I feel like I've made a mistake, but love the bike now.
 

So I don't quite know how i stumbled into the highway speed posts last night but anyway I starting reading one and it concerned me so I searched for more.

Now I hope some more experienced riders can help me here but basically am I am going to destroy this bike in short order if 75% of its life is spent at 70 - 75mph? I've had two bikes for a while now, both my Burgman 400 and my 1999 Honda Helix 250cc scooter and use the Burgman for weekends / long trips and fun. The Helix is same engine size / configuration / horsepower as the GZ and they basically offer the same performance / power, however I've run the Helix at 70 - 75mph for years now (89,000 miles) with no problems and I expected the GZ could handle it the same. From what I read this is not true with the exception of Jonathoniq chiming in on these threads to set everyone straight.

So here is the thing, if it can't handle it then I will be disappointed because I like it but I don't want to just blow engines on this bike for fun. I am happy with the highway power and passing abilities of the bike so my post is not related to that aspect but rather will this destroy the engine in daily use. The reason I got this GZ is because I like the $$ savings from the Helix 250 all these years and I really like it on the GZ to, it does even better on gas and so far the tires are lasting great.

So help me out here with your thoughts - do I sell this bike and looking for another late model Helix to continue on my commute or will this bike handle it. I like the Helix but at 90,000 miles now it's age is showing and its starting to become troublesome honestly - I am not interested in doing what's needed to fix it up either so it will now serve as a backup bike to the GZ and it will assume the commuting duty. But if I got the wrong bike for the job then I will pickup a used Helix or Honda Reflex 250 with about 85,000 less miles than my current one for the task

Also - I read in alot of these posts people are not able to get above 65 or just barely to 70. I am no feather weight at 250lbs, probably 275 with gear and my backpack and mine does 70 without WOT and will easily get up to about 83mph if I want, but I don't regularly go more than 70 - 72 range with a few 75mph bursts to pass trucks or something. Why would mine seem so much faster, it appears to be stock to the best of my knowledge?

Be prepared to blow it up at your commuting speeds. The GZ is not really a higher speed commuter. You can not make it more powerful and tinkering rarely does anything but make it run worse.

The GZ is primarily a 3rd world market bike. You have slightly less than 20 hp and 249cc's. Go for a more powerful bike with faster gearing.

If you can find one of these, it may suit your needs:

http://www.motorcycle-usa.com/235/17...de-Review.aspx

Thanks man!

The GW250 is produced in China and was first introduced there. Built to Suzuki standards and has developed quite a following. Lower labor costs in China allow Suzuki to sell the bike for less than a Japanese built product. A good bang for the buck.

I can't help it but I love this bike and it still makes no sense to me how driving it at 70mph is harming things. I mean according to research done last night its top speed / redline of 9000rpms hits at 89mph. So how can me staying this far from the redline still be destroying it? I understand the air cooled engine probably is not enjoying traffic but the highway speeds baffles me, I am not running it 80+ ever, 90% of the time 68 - 72mph which is well away from the engines rev limiter. I already bought it and love it so I will take the chance and be faithful to maintenance and see how it handles it. I will be the official GZ torture tester LOL

It in no way feels or sounds stressed to me at those speeds and I am not holding it WOT to do them so I just can't understand how I am blowing it up.

It may not sound stressed to you but it will when a valve grenades. Other members have discovered this the hard way. High continuous revs will pound the valve seats to death and proper valve clearances close up. It will sound nice and quiet until there is a bang. That can take out the entire engine.

I think it's like with anything else in the motoring world, if you work it harder, just do more maintenance... I mean, eventually all motors blow. By their very nature, engines have a limited lifespan. If you know what you're getting into, and you take as many precautions as possible, then just ride the bike as you need or like and don't worry too much about it.

There are things you can do to lessen stress, like play with some different gearing combinations. Since you're going to be on the highway and need the top speed, I wouldn't recommend the 16T front sprocket unless you pair that with a slightly larger rear sprocket to counter balance it. You could also stay with the 15T front and get a slightly smaller rear for the same effect.

just keep it, slow your roll, allow extra travel time, and use more secondary roads; I rarely push mine past 45-55 mph and when I do it is done with steady incrimental increase in speed and I limit times at high speeds to 15 minutes or less (30 minutes max); want more speed...ride your Burgman

I've had some lengthy discussions with two mechanics I trust alot and I am glad I did. He said 70mph is not going to destroy this motor but rather will kill the mpg's some. He said the rev limit shows 9000 in his manual and 70mph is more than 1500 rpm's away from this point. Both of these guys confirmed that the bigger concern is the stop n go traffic in the afternoon. Going home is when I am less rushed to get there so I am going to take some state highways I've found recently to avoid all the traffic and they are actually only 8 miles further but have been saving my mental sanity in the afternoons LOL.... As far as the higher speeds he basically said it would be nice to change the oil more frequently and NEVER ignore the valve adjustment interval if I run it harder. But I never do that to any of my bikes anyway so that's no issue. I am going to change the oil every 2000 miles, filter every other time and be the one to find out just how much she can take. I can't believe I've already put 3700 miles on it, but then again I put 520 on it last weekend in the mountains of NC :-)

This thread makes me wonder...

I have heard mechanics and old timers tell me the drawbacks of using to many
revs and to much throttle on a smaller motor as opposed to less on a bigger.

I'm using my bike as a commuter.
I've split my 45 miles a day up in order to keep from having the bike non stop
at freeway speeds.

First few miles are surface streets. Max 40 mph * nice and easy *
Then 7 miles between 55 to 60 mph. * I intentionally keep it under 60 *
Then another 4 or 5 at about 40 mph. * again. Nice and easy *
Then the last 5 or so at 55 to 60 mph. * again. Intentionally no higher than 60 *

Heading home is the reverse.

Pretty much never at WOT.

Is that something this bike can live with for a while?
Or am I gunna burn rings and sink valves into seats doin this?

With regular servicing your bike should last until you are sick of looking at it.

Something you can do to extend tire life for commuting is adjust the air pressure. Set both ends about 2 psi over the 2-up figures on the sticker. It will still handle well and brake well.

I rode my G.Z. for 3 seasons & 35000 Km.When I sold it showed 48000 on the clock.That was in 2010.A woman bought it & it is still running fine today. ;) :)

Yep he basically said this bike doesn't have the HP to run itself at self destruct speeds LOL....

He told me to be-careful in to much walking speed traffic in extreme heat though.

Now that may become an issue for me :~(
But I did know that air cooled engines do have issues with bumper traffic on a hot
summer.

Air cooled bikes have a fine line with cooling and heating issues. The cylinder fins must remove/radiate heat but must also let the engine warm up from a cold start condition.
Never had a problem with my 1988 KDX 200. Large fins to radiate heat during low speed gruelling trails in the warmest of days. My friend had a 1988 Yamaha DT 200 with liquid cooling. It wouldn't cool at low speeds and would overheat, overflow the coolant recovery system and loose all it's coolant. He bought a small fan for it and I installed it for him. Switch for off and on. Simple and effective. The temp guage would still get into the warm zone but amazingly would cool off to operating temp within a minute of idling at the end of a climb.

Adding a small oil cooler to your bike would not only increase overall oil capacity but it would also help keep some of the temps down... Just a thought.

I like the idea of that honestly, I wonder how hard this would be to do on the GZ? I'll have to research it.

It's not that bad. I know there is one someone on the forum, but to be honest it was posted so long that I don't even know where to begin looking...

You can find one specific to the GZs oil fill hole thread, which would be your return line. The bottom feed line, form what I remember is a port that you have to make out of the crankcase. That's the hardest part, from what little I remember. But with the right size hole all of the parts after that are just a matter of mounting and then refilling with extra oil.

You'll have to do some more research obviously. But adding oil coolers to air cooled bikes is very common in the bike world so there should be plenty of info for you to find.

Seems to me that the oil supply line for an oil cooler is attached to the engine where a oil pressure gauge would screw in to check oil pressure. There was some discussion as to whether the added line would actually reduce the oil pressure during regular operation. That in itself is a reason for more in depth investigation of an oil cooler.
A larger oil pan with cooling fins might be possible without any oil PSI reduction. Even an extra half liter of cooled oil might make a world of difference in a hotter climate. Could be a good mod that is maintenance free.

It seems to me....
There are three screws holding a small plate labelled 'oil filter' on the right side of the engine.
Couldn't that be a great place to cnc mill a small round chunk of aluminum that would then circulate the filtered oil out one fitting *here is your cooler* and back into another fitting to return to the engine???
The rest would be easy... I would think...
How many psi does the gn250 motor run it's oil at?

I mean. This is positioned higher than the sump so... Isn't it after the pump?

The more research I've done the better I feel about this bike. I am just not going to worry about it. Do my maintenance and I think it will be every bit as good to me as my old Helix has been :)

'Atta boy

I'll approach this thread from a different viewpoint...

at the end of April I was involved in a low speed collision while on my '09 GZ250; essentially I bounced off the front bumper of a car and the bike fell over on the opposite side; the insurance company inspector took into account anything that had a mark, rub, scrape in addition to the truly broken stuff...luckily the engine guard took the brunt of the hit or the bike would have been totalled due to the additional damage; there were parts on the replacement list that were salvagable and needed some clean up and others were replaced with lower cost aftermarket parts that saved alot of $$$ (important or mechanical necessary stuff was replaced with OEM stuff)

I was a persistent pain in the ass but it paid off...I have my GZ250 back at nearly 97% of what she was before the crash! she has obvious marks on the very back edge of the exhaust and the engine guard that confirm the bike's been down (and I'll lose resale/trade value in the future); I look at it this way...an '09 GZ250 with less than 5500 miles is a better machine than a good quality 50cc scooter (which is what I would have opted if my GZ250 got totalled out);

I have learned to work within the limitations of my GZ250 and hope to have her around for years to come! as an alternate I have an '06 Honda Shadow Aero 750 with @ 10,500 miles...she gets used when riding in a group event (charity/benefit ride) or at higher speeds or to destinations further from home

'Search' helps, here is the 'oil cooler' thread:
http://www.gz250bike.com/forum/showthread.php?t=7085