engine dies and needs choke to start

[Evil Sibhod]

I've got a 2003 gz with 5100 miles on it, I've only had her for 9 months now but I've never had any problems until this happened. Ok, this problem first occurred Friday afternoon when I was heading down a regularly traveled road to the ATM. I was lucky that I was stopping for a red light because as i slowed down the engine died and so i rolled to the red. Right after coming to a stop I just thought it was weird for it to die, because the light is about 2 miles from my house and the bike was plenty warmed up. At the light I tried starting the engine, but it didn't. It made a deep sound like it turned over once, but that was it. The battery is less than 2 months old so it's not the problem (would have been charged from the ride anyways). I tried starting it multiple times as I was pushing it around the corner into a parking lot. This didn't work at all, so I rocked the bike to make sure I still had gas (i was only at 120 miles and don't even worry about filling up for another 50-60, and I know for sure that my petcock was set to On and not reserve) I had plenty of gas, so i tried starting it with the choke, which did a little better, the engine turned over, but it was struggling so i tried to give it a little throttle which killed it. I got flustered so i decided to switch to Res just in case for some reason i got mixed up, and with no choke it pulled the same as the On position, however with the choke it started up and the engine was absolutely RACING. I immediately disengaged the choke and it slowed down to normal and I was off. I was a little worried about the whole situation and so I took back roads getting home, however I had to cross at one busy street (40mph) and of course as I turn onto it and head down for about a minute I could feel the bike slowing down and then speeding back up while I held constant throttle. The engine struggled and died once again as I was slowing to turn, so I tried starting it back up, but it would not cooperate until I used the choke again.

To test the problem out, I've had it occur at both fast speeds such as above, and also at 25mph in my neighborhood. I know Very little about motors both in cars or motorcycles, but I remembered that the last time I filled my tank the semi was rolling out of the gas station, meaning they had probably just got a shipment of gas or whatever, and so it probably stirred up all sorts of dirt and what not. It had been suggested to me to check the main fuel line to see if there was anything clogging it. I removed that and it was perfectly clean, so I put it back on and the problem still occurs. It seems to happen after the engine warms up because after checking the line I took a ride around the neighborhood and it took about 3 minutes for it to happen again.

My apologies for the length, but as I'm sure anyone of you would be, I'm worried heh. Maybe it's her way of getting revenge at me for listing her for sale...

[alanmcorcoran]

Evil, I had similar problems, check my thread "stalling in first 15 minutes." Can't really tell you exactly what fixed it, but my dealer was able to fix it and evidence points to crap in the carburetor as you suspected.

[Evil Sibhod]

Ok well 2 birds with one stone, mostly to point out how little I know about mechanical workings of vehicles, I'll just assume that what I've said meant I suspected crap in the carb heh. After reading a couple more posts, this one seems the most similar to my problem, viewtopic.php?f=7&t=1403 (http://www.gz250bike.com/forum/viewtopic.php?f=7&t=1403) Also a couple things occur to me. I sometimes hear a Pop when I start the bike (this has been a long time occurrence) most often when I get home from work, I roll up my driveway, and usually shut off the bike while I hit the garage keypad, and there is a small elevation into my garage so being the lazy guy I am, I usually turn the bike on so I don't have to push up hill (Interesting story for a celebration after fixing this problem), anyways when I turn her back on I hear a Pop from the exhaust. It ranges somewhere around a drop-pop or snap level, but a bit deeper (acoustics of the pipe) or maybe snapping a large stick in half, about an inch diameter. I've heard that many times since owning the bike but thought of it only as an annoyance. That same pop has been heard while at a stop light and revving a bit at the babes in the car next to me :D i don't think it's really a Back-fire... not of the Uncle Buck level anyways.

And now a question; Is there any other fuel line that the On position travels but the Res does Not? I think a key thing to note is that the bike seems to run fine when in reserve mode, could it be a clog in the petcock? If so, I had a LOT of trouble trying to get that dang thing off, it looks like you only have to take off 2 of the 4 screws that are on the Bottom of it and it would kind of swing open or something, but I never got any of the 4 screws to turn the slightest bit.

[mr. softie]

There are two bolts that hold the petcock onto the tank. Those 4 screws just hold the petcock assembly together. There is a vacuum operated valve in there that only allows fuel to pass when a vacuum is applied, like when the motor is running. This is for the "ON" and "RESERVE" positions. When the lever is moved to "PRIME" the fuel bypasses this vacuum operated valve. So if the bike runs ok on "RES" the vacuum operated valve is probably operating correctly. Look at page 35 of the parts manual. It shows a drawing of the petcock. There are also a few posts on here that show photos of the petcock. Or check here: http://fiche.ronayers.com/Index.cfm/Module/Main/TypeID/26/Type/Motorcycle/MakeID/2/Make/Suzuki/YearID/44/Year/2003/ModelID/6180/Model/GZ250/GroupID/250326/Group/FUEL_COCK If your fuel level is low of course you need to be on reserve for the motor to run. At 120 miles you could be hitting reserve level. Or the tall (ON) fuel tube could be clogged. The tubes have a fine mesh screen portion. To clean them you need to remove the petcock from the tank. Empty the gas into a suitable container and remove the petcock from the tank. I think removing the petcock is easier with the tank off the bike but not necessary. Clean/inspect the tubes/screens. Make sure the little petcock valve vacuum line is attached at both ends when reassembling everything. Sounds like a fuel delivery problem to me. I would check the fuel level in the tank, then the petcock screens, and it wouldn't hurt to put a new fuel line and one of those tiny plastic inline fuel filters on it (auto parts store). Let us know your progress. The post you refer to didn't have a resolution.

[Easy Rider]

It made a deep sound like it turned over once, but that was it. The battery is less than 2 months old so it's not the problem

Other advice is good so I won't go over that ground again.

Terminology is important in trying to describe the problem to others.....and get help.

If it REALLY "turned over" only once, then you have a battery problem. The rest of your message tends to indicate that it was turning over fine but just not FIRING. As far as finding the problem, there is a BIG difference.

A brand new battery CAN go bad; did you charge it before installing it? (Although I don't think that is a factor here).

Before you get carried away, you might want to drain some gas out......incase there is water at the bottom of the carb/tank.
Find the drain hose at the bottom of the carb. See the screw at the top of the hose; that opens the drain. Put the hose in a can or similar.
Put the petcock to PRIme. Loosen the screw until gas flows. Drain out a pint or so. Close screw. Put lever back to ON (forward). Test ride.

[Evil Sibhod]

ok, yeah as I've read I wasn't sure if I was describing it properly, when the problem occurs it does not Fire, but it turns over fine. I have had a battery problem before (before I got the new battery, the old one was probably the original) where it was too cold to start the bike at all, and this was unfortunate because I was at work and it was 2am, so I ended up leaving her there and walking home, pushed her back the next day. I should have known it was going to happen because when I tried to leave for work I had to push start her, which is really putting it in 2nd and rolling down my Very steep driveway. Seeing as this was my first winter owing a bike I wanted to ride as Much as possible, and so even when it was 30 degree Fahrenheit out, I was pushing her up and down the street until I got it running. This was very exhausting, especially for the few times that I actually did give up and had to push it back up my driveway, in gear I could only move a couple inches each push, then would have to rest a bit.

Enough digression, I ride to school every day and so today I decided to just start it in Res and not even try ON, the entire way there, and back I had no troubles at all. This causes me to believe that maybe, JUST Maybe I forgot to roll the trip meter back after filling up, combined with this is the first time I filled up since my winter tank which had a bit of fuel stabilizer in it, "Sta-Bil" which I bought at Advanced Auto Parts, and I just didn't get a full tank because it was still cold and I didn't want it to expand too much or something. I know this much for sure; I was not at my usual fill up point, which is 180 miles.

Basically my question is, should I first try getting a full tank? or at least 2 or 3 dollars worth (I think prices are $1.93 in my area right now). It seems like that at the very least, more gas would just mean I drain a bit more if that does not solve the problem.

[Easy Rider]

Basically my question is, should I first try getting a full tank? or at least 2 or 3 dollars worth (I think prices are $1.93 in my area right now). It seems like that at the very least, more gas would just mean I drain a bit more if that does not solve the problem.

Yes, that sounds absolutely logical to me. Certainly can't hurt.

Another basic item, just for grins.
Petcock:
Lever handle forward=ON
Handle down=PRIme
Handle back=REServe

[Evil Sibhod]

Ok, I just got back from the gas station. Took the long way home with it on ON, and there were no problems. It was only a 3 mile trip, but I got up to 50 on parts so I think I just had some crazy, no reason for it to happen ever, confusion with how much fuel I had. If anything funky happens within the next few days I'll post back.

I can't count how many time's I've checked the manual for the petcock positions heheh, but I finally got the hang of it when I thought, "well it can't turn full circle, so obviously the long end is the indicating end..."

Thanks for all the suggestions and help

[adrianinflorida]

How much fuel did it take to fill the tank? Maybe there is some crap around the bottom of the "On" filter/tube and on most of the "Reserve" tube. Couldn't hurt to take the petcock out next time you're near empty and check for clogs, dirt gunk, etc.

[Evil Sibhod]

I put in 2.5 gallons, and that brought it up to Just below the opening. I'm not sure how much of the 3.4 is dedicated to the reserve, but .9 gallons seems like it would be a lot. More gas still did seem to help though, I took her out a couple times today and did not have any problems in the ON setting.

[adrianinflorida]

According to the manual, 2.7 Gallons in the "On" setting and 0.8 Gal in "Reserve" for a total of approx 3.5 Gal. Of whic 3.3-3.4 is probably useable.

If you put in 2.5, you probably had about a gallon left, and should have been a bit above the reserve inlet. I really wonder if you have some debris casuing some clogs in the petcock.

[mrlmd1]

Why are we all making this so complicated? He may have just run out of fuel and needed the reserve setting to get the bike running again.
Keep track of your miles after you fill the tank (with the petcock in the ON position - see the arrow on the long arm, pointed forward), fill it every 150 miles, and see if the problem is solved. If you have run out of gas and emptied the carb bowl, switching to RES will still take a few seconds to get the bike started, and with the choke on and the engine warm, of course it's going to race. Just don't run out of fuel again.

[Easy Rider]

Why are we all making this so complicated?

I think the "collective" had already arrived at that conclusion!
No need for too much.... :poke2: :poke2: :poke2: :biggrin:

[Evil Sibhod]

well i suppose my biggest error was in guessing how much the fuel would expand between filling it up at 35 degrees Fahrenheit to the projected 70 that it was when I filled up, and this made me forget that I probably couldnt put as many miles on that tank as usual, but it's working fine now

[mrlmd1]

The volume expansion of gas between 35 and 70 degrees is insignificant - I just looked it up on the web and the standard coefficient of gasoline expansion/contraction is 0.069% per degree F. (0.00069/degreeF), and on another site it says the volumetric coefficient of expansion of gasoline is about 0.058%/degree F. (.0.000528/ºF). That's even less.
Using the higher figure of 0.069% expansion/degree F = 0.00069 x # of gal in full tank (say 3.4 gal in full tank) x 35 degrees temp diff = 0.08 extra gal., or less than 1/10th of a gal. difference with 3.4 gal at 35 compared to 70 degrees. Don't worry about it, and don't even think about it, you are not going to be filling up the tank to the very tippy top anyway.
And the fuel in the inground tank at the gas station is pretty much at the same temp all year long when you fill up anyway so you would be getting for all practical purposes the same amount (volume) of fuel each time, whatever the meter says, irregardless of ambient temperature. There may be a difference between Canada in the wintertime and Arizona in the summertime in the amount of gas you get per the meter read, but in one locale, the difference is minute.

[Evil Sibhod]

Yeah, good point, and thanks for looking it up, I was going to but didn't get a chance as I just got home from work. Makes sense though, I just never worried about it with my car because I could leave the nozzle in and just let the fumes hit the auto shut off, though that was back when gas was 4 dollars and my F150 was costing me 45 for half a tank, and I could watch the fuel gauge go down as I drove.