Motor Overhaul (summer project)

[RamAir]

Hello all! :biggrin:

This is mainly to improve the preformance of the bike but I am also doing cometic upgrades as well. But for this post I will be listing all the upgrades with links that I plan on doing to make the GZ 250 more powerful and better overall to ride. I am looking for better WHP AND better MPH. I know not easy but hear me out on this! So, everyone lets begin strap your selves in boys and girls this is gonna be a hella project and a big dream until I start wrenching in summer. HERE WE GO! :cool:

First things first! Theres no replacement for displacement Soooo
BIG BORE KIT!
http://cgi.ebay.co.uk/GN300-GN250-BIG-B ... 0462854879 (http://cgi.ebay.co.uk/GN300-GN250-BIG-BORE-cylinder-Improve-performance_W0QQitemZ280616259810QQcategoryZ10534Q QcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo% 3DDLSL%252BSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA %252BFICS%252BUFI%252BDDSIC%26otn%3D8%26pmod%3D280 589351554%252B280589351554%26po%3D%26ps%3D63%26clk id%3D6909710460462854879)

Need to knows for me, how sure are we that this will just bolt up and work??
Improvemnets on this I will be getting total seal piston rings for the best power and MPG!

Next, CR I would need to do far more research on this but I would like to use the piston rod outta a 1983 Honda VT500. It beeing a V-twin that means it have TWO 250cc banks. Sooo thats like two gzmotors the bore and storke are just about the same but its CR is 10.5:1 so if that rod has the same bores on both sides I can use it and see if it bumps up our CR to give use more power. The V-star 250 is 10:1 and makes more power and is faster then the GZ and uses 87 octain so I am thinking with the right tune and set-up 10.5:1 will not be that bad! Now I know that piston head and cumbuction chamber also play a BIG part in this so I will be looking into it more like I said. Here is this like.
http://cgi.ebay.co.uk/GN300-GN250-BIG-B ... 0462854879 (http://cgi.ebay.co.uk/GN300-GN250-BIG-BORE-cylinder-Improve-performance_W0QQitemZ280616259810QQcategoryZ10534Q QcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo% 3DDLSL%252BSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA %252BFICS%252BUFI%252BDDSIC%26otn%3D8%26pmod%3D280 589351554%252B280589351554%26po%3D%26ps%3D63%26clk id%3D6909710460462854879)

Here is a list of the honda specs.
http://www.motorbikes.be/en/Honda_VT_50 ... _1984.aspx (http://www.motorbikes.be/en/Honda_VT_500_C_Shadow_1984.aspx)

And the GZ specs just compair for yourself.

http://www.mbike.com/suzuki/gz250/2009

Or even looking into piston options from 600CC bikes with the same rod to see if we could get a higher comp piston head.

Also this cought my eye. Anyone know what this is about?? The new 125GZ's are fuel injected??

http://www.bikez.com/motorcycles/suzuki ... 5_2010.php (http://www.bikez.com/motorcycles/suzuki_marauder_gz125_2010.php)

Really? :retard:

Also I wanna do the oil cooler idea.

viewtopic.php?f=9&t=3943 (http://www.gz250bike.com/forum/viewtopic.php?f=9&t=3943)

And I wanna do up a ramair intake system and heat wrap the exhaust pipes and get a new exhaust system

http://www.youtube.com/watch?v=rkMQu-Fe ... ure=fvwrel (http://www.youtube.com/watch?v=rkMQu-FeRf8&feature=fvwrel)

More for looks and personally I think it would sound better once its a 300cc bike :drool:

And I will also be doing what this member did with the PP and new parts. Pretty much I will be ripping off all the work he did. And if he is still on here that would be great if he can give me some pointers or on how much better the bike was after all of his work.

Here is the link.

viewtopic.php?f=9&t=3050 (http://www.gz250bike.com/forum/viewtopic.php?f=9&t=3050)

And a gas tank mod and all that but thats another thread.

So to sum this up I wanna do the
Big Bore Kit.
Total seal rings.
Port and Polish.
Cold air Ram air intake system. Custom done by me.
Exhaust system. To over all help flow and help the bigger motor breath better. Same deal with the P&P.


aND i AM HOPPING THAT AFTER ALL THIS i CAN DO THE 16TOOTH MOD OR PLAY AROUND WITH THE REAR GEAR AND GET A TALLER RATIO OVER ALL AND STILL HAVE THE SAME PREFORMANCE AS BEFORE WHEN IT WAS JUST A 250CC BIKE BUT OVER ALL BETTER HIGHWAY POWER AND BETTER mpg SINCE i PLAN ON RUNNING A TALLER FINAL DRIVE RATIO GEAR!

:popcorn: :popcorn: :popcorn:

Any and all edvise and information and input will be most welcome! Sorry if there are any weird mistakes my computer screen is acting up and I cannot fully reveiw what I have typed.

Thanks again guys! :2tup:

[RamAir]

The big bore kit says our motors make,
20.78 HP at 249CC
and the kit will make,
25.47 HP at 298CC.
By my calculations it should be making
24.86 HP at the crank.

Plus all of the other mods I am hopping to be making atleast 20hp at the wheel. maybe even 25hp when fully done. Bumping up the CR will also help.

Just as I posted about the honda bike.
Our stroke 61.2mm
Honda bike 62mm.

Not sure what .8 of a mm will do but until I get more specs and an online CR calculator I willnot be sure of anything.
Also a side not the V-star 250 that has a CR of 10:1 has an HP rating of 21HP over our 20HP. So I could see anywere from .5 to 1 hp with a CR of 10:1/10.5:1. However the V-star have a longer stroke and is more set up more trq then our bikes and more factors should be takin into consideration but 4.5 to 5 hp jump for the big bore kit, .5 to 1 hp jump for higher CR and 5% to 10% increase for the P&P And 5% to 10% for the total seal rings (keep inmind that the (&) will go up with the motor so its 10% power for a 300CC motor once the big bore is done) about 8 hp hopefully and 5hp realistically! Not much, not much at all but lets wait and see! :D

[Water Warrior 2]

Wow, that is quite an ambitious plan. I would really like to see it happen but I'm afraid you might be setting yourself up for an engine meltdown or grenade. The big bore kit sounds great and is more than likely a plain simple R+R kind if job. However I would be leary of trying to raise the compression. A bigger bore, a little more intake and exhaust flow will probably make a noticeable difference without stressing the various parts overly much. That and an extra tooth on the front sprocket will make the bike seem a lot bigger and better.
You mentioned the Yamaha 250. Don't be mislead by it's numbers, it is a V-twin to begin with and has it's own set of rules to play by. I'm not trying to rain on your parade in the least, just me and my err on the side of caution attitude after a few experiments years ago that didn't work out well.

[RamAir]

WW This is what I am talking about man You speaking from been there done that will really help me!

Also This is a two or more maybe year plan. This summer when I pull the motor apart and see if I can save the bottom end then I will be going BB kit. And if I can P & P I will but the CR bump up and the exhaust and all the other stuff will ahve to wait till I can get my hands on a connecting rod or atleast the specs of one.

I head what your saying about the drive train and putting almost 50% more stress on all the parts then they where built to take. But when I am cruzing down the road or highway at half throttle I am putting what about 10hp on all the parts, they were ment to take that stress daily! Now every now and again when I really push it thats when they will have all that power and pressure on them but if its every once in a while it should hold up fine. Thats why the BB kit first and PP and see how reliable it is then I will be moving on! Also that is why I want the oil cooler. So that it helps keep everything living longer and keeps it all healther!

[RamAir]

ONE MORE IDEA

I was planning on Frankensteining a motor. I posted about this viewtopic.php?f=9&t=2777 (http://www.gz250bike.com/forum/viewtopic.php?f=9&t=2777) and a lot of members really helped me out BUT if it is true that the newer heads do have a bit better flow AND get 1 more MPG man then I say do it!! Since my top end spun I am looking for an almost new to new one! And if I was to keep my bottum end, newer cylinder head this would mean.
Better flow.
More MPG.
BB Kit.
P&P < (The added flow of this would complement the newer heads)

And since it will have an oil cooler (I will look for oil coolers for 300CC bikes since the BB kit is what I am after) it will keep it cool. And since they did not report any power losses with the newer head desings I am figureing all my numbers SHOULD still be pretty much the same!

There is more to this project but if I tell all most here would strat to hate me :neener:

[Water Warrior 2]

I was going to suggest using a 2 valve head for a cooler engine but then my memory kicked in. The big bore pic shows a piston with cut outs in the top for 4 valves.

[RamAir]

Our motors have a 2valve set-up?

If I can amek the oil cooler work I dont mind running at normal temp sence that means its working.
What head has 2 valves?? Plus I want the 4v for better flow! :)

[Water Warrior 2]

Older GZ engines had a 2 valve head. I think you might be hard pressed to find one though. Let's just forget I brought it up.

[RamAir]

Forget what? ;) Still the more info the better! You can never know to much!

Any what edvise would you give WW since you are speaking from past expariance. And also what have you tried in the past?? Any posts of it on here?

[Water Warrior 2]

Past experience and advice ? You can spend a pile of money to achieve nothing noteworthy. For every small achievement that works rather well you have created at least 2 disadvantages that will haunt you later.
Rather than trying for more power, performance or pizzaz I learned to concentrate on reliability and ease of serviceing. I learned the designers of cars, trucks and bikes are better equiped than I am to make things that don't break. I gave up on aftermarket performance parts and stuff because you are at their mercy when things go south. OEM parts are more readily available and they have a better overall quality to them.
I haven't tried modding an engine for a long time and have never had a stocker go bad or die to soon. But don't let me dissuade your plans. I want to see the results with younger enthusiasm and more resources thanks to the internet.

[RamAir]

More resources?? I ahve a 250 cuz I am poor! But whatever you say WW. hahaha But Ill take the yoounger enthusiasm as a good thing! :P Unless you mean young and dumb, jk. The only way you could discourage me outta doing these mods is by telling me you have tried all of them for yourself and not one worked. I am guessing that is not the case?! :D

[music man]

The only way you could discourage me outta doing these mods is by telling me you have tried all of them for yourself and not one worked.


They probably all work, the only question is, and it has been asked on this site many times is, are you going to get anywhere near the performance gain you would need to get to be worth all the time and money you are going to sink into this, and maybe more importantly, how long is your engine, or just the entire bike in general going to last if you do get those kind of gains.

Not that I am saying don't do it, quite the contrary, its your money and your motorcycle, and after having several people come on this site claiming that they were going to do basically this same thing, and then all of a sudden disappear, I am hoping that whether you fail or succeed on this project, that you will stick around and tell us the bad and good of doing stuff like this to the GZ. And hopefully you will stick around long enough to tell us the long term effects of them too.


Good luck

[Water Warrior 2]

More resources?? I ahve a 250 cuz I am poor! But whatever you say WW. hahaha But Ill take the yoounger enthusiasm as a good thing! :P Unless you mean young and dumb, jk. The only way you could discourage me outta doing these mods is by telling me you have tried all of them for yourself and not one worked. I am guessing that is not the case?! :D
Young and searching for knowledge and experience.

I am wondering though, is the cost of these mods going to any less overall than just insuring and operating a 500 cc bike with the performance you can use without all the wrenching and potential reliability issues down the road ?

[RamAir]

Ok how about some numbers.
New (meaning old used motor) $600 Canadian BUCKS! <<<< There you go boys theres my summer money!

Oh wait first things first WW Are you adding in the cost of 3 or 4 grand for that 500CC bike. If all these mods work I plan on keeping this bike for years untill my insurance for a loarger bike falls within what I have set aside as yearly insurance allawonce for myself!

BB kit. about 100 bucks.
Newish head. what? 100 to 200 with cam and all.
Oli cooler what 50 bucks?
So total 350 bones.
New uesd motor 600.


Also If and when the motor is running with all these mods then I will pick a weekend and do the PORT AND POLISHing. Again That guy never replyed to his thread other then once to say how it went but from that one post he posted good things.

You guys tell me ;)

Bam my motor is now running considering the bottom end is fine cuz these motors up around here are hard to come by!

So right there in the aboce since I plan on oil cooler BB kit and newer head for this summer ythen I am good to go so...

Plus all the port and polishing will be great practice for future projects. GUY KEEP IN MIND I plan to own bike in the future and mod them both crusers and sport bikes. I even wanna get into racing them. And why not practice on a cheaper bike like the gz where oem and after market parts are not that bad when it comes to cost. Btter to blow $600 GZ motor then a $1500 V-star or honda shadow or whatever else bike you wanna include in this sntince!

And if after all of this work does not infact work out I will be parting out the bike or selling it as a parts bike and taking a year or two off to save up and get a bigger bike. And since I will be older insurance will also be cheaper.





NOW What I need here from poeple would be help with the carb jets. I need to know what size I would need for a 300CC bike.
Also factor in that you guys who do the carb jet mod do it for a 250cc bike. I want the same increase you guys give your 250s to mathimadically be the pretty much same on the 300CC motor. Am I making any cents here? LOL Bear with me. sorry :P

[blaine]

When I re jetted my carb I went from #120 M.J to a #132,shimmed the needle,and adjusted the idle jet.I was running a after market exhaust,and air filter.
:cool: :)

[Water Warrior 2]

That sounds like quite a quest for knowledge and experience. Now your ideas make more sense when the future bikes and plans are added in.

[RamAir]

That sounds like quite a quest for knowledge and experience. Now your ideas make more sense when the future bikes and plans are added in.


Yes you are right Sir. WW I should have also added that in. Just like a winter beater car that I ahve with the turbo motor I just put in the thing.
Car 300 bucks! Almost NO RUST One owner (my friends dad Ii knew the guys)
Doner car with short block rebilt motor 350 bucks. Plus newer suspenssion from the car and a whole bunck of other stuff


Supplys and all will run me in the thousands when the car is at the standerd that I want it to be but for a $650 dolla car with almost new motor and almost no rust body its a great learning project.

I also went to school for auto mechanics for 2 years and once I am done studing for my other carears I will start on my way to becoming a lincensed tec.

So I hope all of you see that there is method to my madness now although be it extream madness yes. :retard:

[RamAir]

Blaine I am guessing you left the idle jet alone? And did you get the jets from eboy?
Thanks for the input. And you to WW.

P.S. If anyone sees me going in a bad deriction throught this build speak or rather type up. It takes a lot to offend me and if its gonna save me time, money and stress then thats even better. I am not trying to sound cocky or that I am such a great handy man here. I just like to dream big, then when I wake from my slumber I make my dreams come true azz all! :D

[blaine]

Blaine I am guessing you left the idle jet alone? And did you get the jets from eBay?

Yes,I only adjusted the idle jet.I bought the M.j. from a after market shop in my area.This shop is a excellent shop that can order me almost any after market part I need,without the hassle of ordering from eBay,or the extra cost of shipping.Any good motor cycle shop should be able to provide you with the M.J.s you need.
:) :roll:

[RamAir]

Sorry M.J.'s? Motorcycle jets??

[blaine]

Sorry M.J.'s? Motorcycle jets??

Main Jets. :biggrin: :cool:

[trykemike]

Hey Ram !

I like your enthusiasm . When I was 17 I had a 125 cc honda parallel twin. Small bikes were the norm. Yamaha 100 cc twins suzuki 120 cc singles honda 150 cc twins. I needed more power so I had a custom cam-shaft ground and 160 cc honda pistons and a velo-stack and uped the main jet from 75 to 95 and added shorty triumph mufflers with out baffles. Performance gains were incredible. The bike could burn 6 feet of rubber and wheelie at will. Top speed increased from 68 to 80 mph. Fuel economy was 40-50 mpg. The bike made weekly trips from scarborough to wasaga beech at 60-70 mph. I had fun and once drove to parry-sound and back. I later bought a 350 cc honda scrambler and only removed the baffles and richened the mixture. THE 125 WAS A LOT MORE FUN.

[RamAir]

Trykemike You just added fuel to the fire my friend!

Now I dont think Ill be grinding get a custom cam-shaft we will ahve to wait and see. But some stuff I am dreaming about is a 5angle valve job, ceramic coating the whole cumbustion chamber, head, valves, piston top, and so on and so on.
My Ram air set-up (if I can get some kinda pics Ill have to put them up) will have velosity stacks on both intakes.

You still livin in scar town?

[RamAir]

Does anyone know the size of the SUZUKI GN 400 mian jets?

Cuz what I can ruffly calculate a (I am guessing its the size) 144 jet would be great for a 300cc bike and a 158 or 160 would be great to making more power with a 300cc motorbike. Does tha sound about right?

[RamAir]

OK GOT A QUESTION! Hope I can get some help!


Gonna be pulling apart the motor that spun the top end soon and wanded to ask if the lower end looks good just bolt it back up? I hear never reuse rod bearings and stuff like that but I mean if they good and I dont need them will my motor be fine to just slap it abck together?

[blaine]

OK GOT A QUESTION! Hope I can get some help!


Gonna be pulling apart the motor that spun the top end soon and wanded to ask if the lower end looks good just bolt it back up? I hear never reuse rod bearings and stuff like that but I mean if they good and I dont need them will my motor be fine to just slap it abck together?
If you are not dissembling the bottom end,You should be fine,just to put a new head on. :cool: :)

[RamAir]

I wanna take the whole motor apart. It spun the top end but it still had all the oil in it! I think it cloged a vane or something like that and thats why it spun the top end. I just wanna be sure that the bottum end is fine! Although you have a good point that would save me a lot of time. I am just worried that its cloged near the pump and I bolt a new head on and it spins thta as well! :O

[RamAir]

Are there any rebuild kits anywhere for our motors? I cannot seem to find anything really.

Also anyone running a wider rear tire? or front?

[blaine]

Are there any rebuild kits anywhere for our motors? I cannot seem to find anything really.

Also anyone running a wider rear tire? or front?
Don't know about the rebuild kit,but I ran a 140 on the rear of my G.Z.
:) :roll:

[RamAir]

Ya ill take a lookin at Suzu but I dont want it costing half a bike just to get the motor like new.

And you had no problemo on them 140 rear?

[blaine]

No problems.With the 140 tire,it changes the gearing about half between the 15t and 16t as it is wider & not as tall.
:cool: :)

[RamAir]

Hmmm that would be a nice comprimize!

Why is it not as tall? Whats the overall tire size? I mean all the numbering?

[blaine]

Hmmm that would be a nice comprimize!

Why is it not as tall? Whats the overall tire size? I mean all the numbering?
Same size as original tire.The wider the tire the lower the profile.140/90-15.
:cool: :)

[Water Warrior 2]

The 140/90-15 is 4.96 inches in height.
The 130/90-15 is 4.606 inches in height.
The 140 will give you slightly taller overall gearing.

[blaine]

The 140/90-15 is 4.96 inches in height.
The 130/90-15 is 4.606 inches in height.
The 140 will give you slightly taller overall gearing.
Thanks.I didn't know the difference in height.But I could feel the difference with it on the bike.
:cool: :2tup:

[Water Warrior 2]

The 140/90-15 is 4.96 inches in height.
The 130/90-15 is 4.606 inches in height.
The 140 will give you slightly taller overall gearing.
Thanks.I didn't know the difference in height.But I could feel the difference with it on the bike.
:cool: :2tup:
The width is 130 mm. 90% of that figure is the height
The width is 140 mm. 90% of that figure is the height. This will raise the bike a whopping .354 inches. Total height of the tire will be 0.354 x 2 = 0.708 inches. Oh boy, maybe I should figure the difference in the amount of rotations in a mile now. Then I could figure out the actual difference in gearing based on those figures...................or I could just go for a walk.

[mrlmd1]

"This will raise the bike a whopping .354 inches."
And that's at rest, unmounted, not weighted down on the bike by the weight of the rider, fuel, frame, etc, compared to the other tire. So the effect is probably not even measurable or noticeable by a rider. If the tire diameters were actually measured on a fully loaded bike, my bet would be that they are even closer in measurement than what WW posted,
I think the difference is in your head. :poke2: :neener:

[blaine]

"This will raise the bike a whopping .354 inches."
And that's at rest, unmounted, not weighted down on the bike by the weight of the rider, fuel, frame, etc, compared to the other tire. So the effect is probably not even measurable or noticeable by a rider. If the tire diameters were actually measured on a fully loaded bike, my bet would be that they are even closer in measurement than what WW posted,
I think the difference is in your head. :poke2: :neener:
The only time I noticed any difference was on the hills,it might also be the weight difference of the tire.I also had the 16t sprocket .Like you said,the difference might have been in my head.
:2tup: O_o

[RamAir]

Ya when you said "cut the gearing in half" I thought you got a 140/45-15 tire or something!!

WOW 16T na d a 140/90 I wonder what your rpm is on highway speeds! Must be nice and quiet! Man you must get great MPG Also with all that combined! Niceeeeeeeeeeee.

[Water Warrior 2]

Ya when you said "cut the gearing in half" I thought you got a 140/45-15 tire or something!!

WOW 16T na d a 140/90 I wonder what your rpm is on highway speeds! Must be nice and quiet! Man you must get great MPG Also with all that combined! Niceeeeeeeeeeee.
If I remember correctly a 16 tooth front sprocket cuts the RPM by 400 or so. And a 140/45-15 rear tire would be a really really really low profile tire. The overall diameter of the tire would be less so the RPM would increase.

[RamAir]

At WW No earlier when blaine said it cuts the rpm by half I thought he had a lowpro tire!

But with a 140/90-15 its a bit larger! Plus the 16T so I would say his RPM are what 450 or even 500 less on the highways?

I wonder what 5th feels like around town! :)

[Water Warrior 2]

At WW No earlier when blaine said it cuts the rpm by half I thought he had a lowpro tire!

But with a 140/90-15 its a bit larger! Plus the 16T so I would say his RPM are what 450 or even 500 less on the highways?

I wonder what 5th feels like around town! :)
Not good I would think. You would not have any real power to get out of the way of trouble. 3rd and 4th might be kinda nice though.

[blaine]

3rd & 4th was excellent around town.Forget 5th.I wish I could change the gearing so easily on my 454,but it's belt drive.It comes with a 140/90-15 tire.I can go up to a 150/90-15.It don't help that it is basically a sport bike engine in a cruiser frame.At 60 mph it's revving right around 5500 rpm.But that's the nature of the beast.These little engines love to rev.
:) :2tup:

[RamAir]

At WW No earlier when blaine said it cuts the rpm by half I thought he had a lowpro tire!

But with a 140/90-15 its a bit larger! Plus the 16T so I would say his RPM are what 450 or even 500 less on the highways?

I wonder what 5th feels like around town! :)
Not good I would think. You would not have any real power to get out of the way of trouble. 3rd and 4th might be kinda nice though.

When no one is around me and I am on flats or even a little bit of a down hill (simply put in a postion that will not put stress on the motor0 I almost always am in top gear as long as the revs are high enough that the motor is not shaking or sputtering. That way you get the best MPG IMO anyway. :rawk:

[spicciani]

I hope you document this throughly , sounds like a great project

[RamAir]

Oh yes pictures and everything.


However I have not even been able to get my bike on the road yet due to lac of funds! Having expencive toys and needing new tires and all really sucks! Boooo.

Also I have not posted on here in a while but this is not just a reply post its also a "I am still here and this is still on" just barepaw with me here poeple it will atke some time :(.

[geezer]

if your using brand new pisto pin bearings i would go for it. i wanted to warn y about port and polishing. i belive that its bad for the carb'd vehicle due to reduced tubulance in the intake track. the air and fule wont full y mix. if i wer you i would do some research maybe go see a machinest and ask ther opinion

[RamAir]

if your using brand new pisto pin bearings i would go for it. i wanted to warn y about port and polishing. i belive that its bad for the carb'd vehicle due to reduced tubulance in the intake track. the air and fule wont full y mix. if i wer you i would do some research maybe go see a machinest and ask ther opinion


Thank you very much geezer I really do appreshiate it! I do not minde anyone chimeing in with anything they think might be helpful on this or any build. The worst you could do is post something wrong, I will be checking everything I wanna do with pros!

I was considering one of two things for what your say geezer and belive you me I have considered that cuz even on PFI its the same thing, pretty much only derect injection is where it would help when PP, or forced induction.
I would love to source out a 08 or 06 head cuz thats when they made the domechanges to get one more MPG outta the bike, (they ran hotter but since I ahve the oil cooler I fig. no big right) but anywho having two heads and doing the PP myself on one head while still riding the bike. So no cost or downtime for me and then I just switch them, and if its not that great I can always go back and switch them again.

Two! I was gonna fab up a 'ramair' intake system on the bike and use those stu[ed little turbonotics things that they say inproves HP and MPG. Thats not why I would want one I want one to make the air swire around in my intake tubing cuz once I PP everything smooth I need something to help mix gas and air.


Let me know what ya think :2tup:

[blaine]

I would love to source out a 08 or 06 head cuz thats when they made the domechanges to get one more MPG outta the bike, :2tup:
They came out with the"swirl combustion" head in the 04 model year.
:biggrin: :)

[geezer]

wow dude you got it at all angles :2tup: still bottom line i would go see a performance engine builder and see. i happen to kno wthat those swerl things are a scam, they do nothing but act as a restriction. and once the so called "mixed air hits the carb it will go back to where it was and you still wont get the swerl you need for proper cumbustion. i actually went to school for 2 years on automotive and thats where i learned this stuff. if i were you i would make the intake and exhaust ports bigger, gasket match and 3 or if possible 5 angle valve job and thats where you will find more power. as i said if you think im full of it go see that engine builder.

someday ill have a GZ300 i cant wait to i plan on leaving the bke stock looking but getting new emblems made that say gz 300 instead of 250 that would be pretty cool

[Water Warrior 2]

wow dude you got it at all angles :2tup: still bottom line i would go see a performance engine builder and see. i happen to kno wthat those swerl things are a scam, they do nothing but act as a restriction. and once the so called "mixed air hits the carb it will go back to where it was and you still wont get the swerl you need for proper cumbustion. i actually went to school for 2 years on automotive and thats where i learned this stuff. if i were you i would make the intake and exhaust ports bigger, gasket match and 3 or if possible 5 angle valve job and thats where you will find more power. as i said if you think im full of it go see that engine builder.

someday ill have a GZ300 i cant wait to i plan on leaving the bke stock looking but getting new emblems made that say gz 300 instead of 250 that would be pretty cool
Geezer take a moment will ya. Air and fuel meet and greet in the carb. Go hand in hand to the intake valves and then into the combustion chamber as the swirl head gives then a whirl.
Are you actually thinking of one of those aftermarket devices that swirls the the air before it enters the intake and fuel system. Commonly sold for cages.

[geezer]

yea i was thinking thats what he was talking about, the spin disk things people put into there cars thats supposed to give air a denser charge or sumptin. i guess i misunderstood him. but my point still stands, port and polish in my opinion is not a good idea, the end

[jonathan180iq]

From my experience, port and polish is a great idea on most applications, if you are racing.
Port matching manifolds and smoothing intake and exhaust ports are only going to help increase air flow in and out of the engine. Thing is, most people don't ever really need anything more than the factory job and honestly probably couldn't tell the difference anyway... Especially the casual rider.

And those twisty intake things are crap. ( I fell for them when I was younger. http://turbonator.co.uk/) The only way to get more air into the chamber is too cool it, or force it in, or both. You can make one yourself and test it if you don't believe me. All they do is take a piece of scrap sheet metal and cut little teeth in it and bend them so it looks like it might create a vortex.

[RamAir]

Thanks for the input guys kep all that good info and years of expiriance comin! (muahahah I will learn!)

Ok fo the record I ahve heard of engines not runnin right with a PP, and no they where not racing them so ya I agree if your gonna be pushing the motor and so on a PP will be great. If you go to get milk and back then you will just waste your time and money.

Jonathan you said about Port matching, YES I 100%, its pointless to PP something then slap it onto someyhing smoller!
One peace of edvise someone gave me that used to race, build race cars and engines and so on is (he also did it with his head when he worked on them) (side note yes a 5 angle valve job is in future works when the head be be'in PP'd) he told me make sure everything is "glass smooth!" Your valves and head! That way you get great air flow, and its much harder for carbon to stick to it and build up on it! He also said when you take your head in and its beeen cleaned up nicely and its all the head rebuilder will take a look at the head and know that whoever brought that head in means busniss and not just, ya a five angle job cuz iot sounds cool, and he wil take his time on your head and do a great job.

Ill find info that shows the cut swerls inprove airflow! Now this was just on a headed peace of pipe not a motor demanding airflow! Like I said I will be moving the intake (if I can do it well and nicely) to the front of the bike with a volacity stack right after the filter to help airflow. And what I wanted the swerly things for was to better mix the gas and air. I was even thinking of looking into some kinda small swearl pattern on the valves themselves so thta when the air was comin right off them it would spin up.


Its not to get "more air" inthe motor (thats what my ramair setup will be for) its to get the air/fuel mixing better since I will be removing all turbulance in the head before the intake valves.



THERE YA GO YOU ALL AHVE MY PLANS NOW! Go nuts with the edvise! I love learning. Again I have to look into what i just type down here. Cuz this stuff is all wants but if I find info that saiys "waste of time/money" "dont do it does not work" and so on I will change my plans! This is a wishlist and I will see what os doable and so on!

[jonathan180iq]

If you're going to do this, let it be done by a shop with experience. It is possible to "over-polish" , if you will, and actually wear away at the surfaces causing mating suface air leaks, which is something that you don't want.

[RamAir]

If you're going to do this, let it be done by a shop with experience. It is possible to "over-polish" , if you will, and actually wear away at the surfaces causing mating suface air leaks, which is something that you don't want.


I will only be polishing where the air will be running into the motor and the dome, not where the valve seats or any other places like that. Ya I know when you redue that you use the sandy like stuff to set the valve into the valve seat so that it seals full. (I have also takin to years of automechanics in school ;) cuz thats what I wanna be when I grow up! LOL) Thanks I will be consalting rebuilders and friends who have raced and built there own cars and see what they say. PLEASE keep in mind this is just for better airflow and will not be for racing or superhigh preformance but it will be a good experiance for me to partice on a smaller motor before I start PP my cars heads. And will not take like 40hours to do this, I will take my time and do it right but I will not be spending enourmouse amounts of time on this cuz its just not that worth it. I just want MORE GZ under me! :rawk:

[geezer]

what you want and need is more torque! have fun bra

[RamAir]

About as much as you can get outta a 250! I just want more! I dont have the money for a bigger bike and I love the GZ. Its so cheap to run and all. Plus if I put enough work into it I might just keep the bike in the family! We will see. I will make sure all that I learn and do ends up on here!

[RamAir]

One more thing I should add. I am also looking into going LED for the front and rear turn signles and the rear brakes light! It will be less drow on the electrical system, small yes but might pic me up a MPG on those long trips and so on!

[geezer]

see thats the beauty of this bike, cheap and easy, so get in ther and tear shit up!

[jonathan180iq]

One more thing I should add. I am also looking into going LED for the front and rear turn signles and the rear brakes light! It will be less drow on the electrical system, small yes but might pic me up a MPG on those long trips and so on!

All of the Suzuki cruisers use the same turn signals. So if you can find LEDs for one, they should work on your bike.

[RamAir]

One more thing I should add. I am also looking into going LED for the front and rear turn signles and the rear brakes light! It will be less drow on the electrical system, small yes but might pic me up a MPG on those long trips and so on!

All of the Suzuki cruisers use the same turn signals. So if you can find LEDs for one, they should work on your bike.


Ok great! Ill post what I find and so on.


And @Geezer addaboy! You said it myfriend! :rawk:

[Water Warrior 2]

Signals and brake light are only on for a short time. There is really no noticeable advantage spending the $ for LEDs. The front amber running light portion of the signal and the tail light have a low power draw. If you replace your signals with LEDs the flasher will not work properly so then you need to buy an inline load gizmo to make things work. You defeat any power saving and spend bucks doing it.

[geezer]

dont led's use less power, thus needing the resistors aka gizmos?

[blaine]

dont led's use less power, thus needing the resistors aka gizmos?
Yes,the led's use less power,but what is saved is used by the load equalizer (resistors) to balance things back out,so the signals will flash.One way around this is to remove the flasher wires from the relay and install a electronic flasher.
:) :cool:

[mrlmd1]

That's a mod for lots of money and very little, if any, gain.
And I seriously doubt switching to a few LED bulbs will affect your fuel mileage, other than by lightening your wallet so there is less net weight to push around.

[RamAir]

That's a mod for lots of money and very little, if any, gain.
And I seriously doubt switching to a few LED bulbs will affect your fuel mileage, other than by lightening your wallet so there is less net weight to push around.
:haha2:

True to that point! But mostly I owuld like it for the looks! Done right LEDs doo loook sweet!

And yes you are right, this is not some stretch limo with tens of lights on at once. :whistle: