my 2008 gz250 cut off on me while going 50mph....???

[Shearerforce]

Hello all...I just bought a used 2008 gz250 with 1890 miles on it and the guy took really great care of the bike. I have personally put 147 miles on it so far and have not changed a thing on it. Yesterday I was riding about 10 mins into the ride at 50 mph and the bike stutterrd and lost power a few times then completely shut off. The bike had been perfect prior to this happening. Everytine I have ridden the bike I have had no problems. I coasted to the side of the road and tried to start the bike again. It took a few tries but it started and idled fine. I started back on my way home and the same thing happened at varying speeds such as 30mph and 40 mph. After the bike cutting off about 8-10 times on the way home which is normally a 15 min trip I finally made it. I let the bike sit as it was very hot(motor) and I was worried I blew it up or something. I tried to ride the bike later that night around my neighborhood to see if it would do the same thing and it did. It shut off while gping slow and when I pulled the clutch in. I rode for about five minutes and it cut off about 6 times. I made it back home and parked it. I have not ridden it since. Any ideas on what this could be.....Thanks! Really appreciate any insight.

[Water Warrior 2]

First thing to do is check the oil level. It should be done with the bike in an upright position when you check it. The engine may be low on oil and overheating due to lack of lubrication.
Did you get a maintenance history with the bike? This is very important. Have you ridden before? Owned a bike before? Do you have the owners manual for the bike? All relative questions so we can get a more accurate picture of the bike and your experience and capabilities.
Likely the problem is fuel related but check the oil first. Then go on to fuel comments that will soon pop up to help you and the bike.

[Shearerforce]

I have checked the oil level when the bike us warm and it is right in the middle of the glass circle. Tgis is my first bike although I have had several dirtbikes growing up. Tge guy who I bought it from told me he did the break in oil change at 600 miles but other then that nothing. I called him the day it happened and ge was confused on why the bike was doing that. He said it never happened to him. If it wasnt snowing putside I would go test the bike again....Yes I said snowing! Ugh.

[Shearerforce]

I do have the manual as well.

[mainlinecoffee]

The only components needed for internal combustion is fuel compression and spark. Can you check that the fuel is flowing? Can you check for spark? If it is very hot then it may be warping he cylender head or valves. My Harley got so hot in fifteen minutes I burned the logo in to my thumb when I went to turn it off. Also I am fairly certain that you check the oil cold but don't quote me on it,better to have too much than not enough. Is it possible that the fuel Petcock being vaccum operated is cutting out due to dry rotted lines? Maybe the ignition coil is very sensitive to heat. Can you get a accurate reading of how hot the head gets? I'd be wary of anything over 240 f.

[5th_bike]

Sounds like the gas tank needs a fill up.

Put the gas valve on "RES" (petcock handle pointing rearward) and visit a gas station. There, put the petcock back on "RUN" so you have reserve.

[Shearerforce]

I just checked the oil with the bike cold and upright and the reading was full. I cannot get a temp reading. I am very new to this bike. I am planning on taking the spark plug out to check for spark. Tomorrow it will be better weather and I will beable to do that. Also The lines look in good condition but I wanted to check them for clogs. I appreciate all the help. The bike is so new I feel like is has to be something simple.

[Shearerforce]

I will fill the tank for sure. I know it has a good bit in there....Could it be bad gas?

[Water Warrior 2]

I will fill the tank for sure. I know it has a good bit in there....Could it be bad gas?

Most certainly if the gas has been in the tank for quite a while. It is winter right?? How long was the bike parked and when was it last ridden by the previous owner?
I would suggest installing an inline gas filter and adding a fuel additive to help get rid of any deposits from our modern gas that has such a short shelf life. The filter will catch stuff from the tank before it gets to the carb. Anything in the carb will hopefully dissolve and go away. Worst case scenario is removing and cleaning the carb properly. We have a bunch of members with lots of carb experience and will set you right. I am not one of them with hands on experience. Lynda's GZ always ran like a champion no matter how long it was parked.

[Shearerforce]

When I bought the bike it had about 3/4 of a tank. He rode it seldomly as he told me and I ran about 50 miles or so on that tank of gas. I filled it with 87 regular. I am chompung at the bit for tomorrow to beable to check everything out that you guys have been telling me. Thanks so much for the help!

[mole2]

I will fill the tank for sure. I know it has a good bit in there....Could it be bad gas?

As 5th Bike said, you could be low enough that the main pickup tube is sucking air. Try what he said and see if it runs.


:)

[Shearerforce]

Well to inform I checked the hoses and oil level and spark plug. All checked out fine. I went to the gas station and the bike cut out on me one time at the top of a hill going about 15 mph. I sat there for a minute and sped the idle speed up a bit after a try or two of trying to start the bike. It started up and I cautiously made my way on a two mimute ride to the gas station. I filled up with 89 octane. I hope that is ok....I guess I wanted to burn some higher test to get the bike back right. Im a rookie. But amyway the bike began to idle nicely and the throttle response was quick on a small rev. I rode home with no problems and rode around a bit more to make sure. I am hoping the problem is fixed and I can continue to ride confidently in the reliability of my gz250. Thanks again for the help amd I know where to come when I have a problen.

[Water Warrior 2]

Sounds like an easy fix if that was the problem. The GZ only requires the 87 octane and runs best with it in most conditions. The biggest market for the GZ is 3rd world countries where gas quality is marginal at best.

[jonathan180iq]

Yeah, 89 octane isn't necessary and didn't change anything. It's a full tank of fresh gas. That's what made all the difference.

You'll learn more about octane and things spending more time around bikes in general but especially on this forum. The whole "Good - Better - Best" thing is purely hype. Unless a motor is designed to require fuel that needs to ignite at a higher temp or under more pressure (or it needs fuel that will help inhibit knocking) then you're actually only wasting money if you splurge on the higher octane stuff.

89 isn't really a big deal - but 93 is harder to burn in our little crappy sewing machine engines and you'll end up with less power and poorer gas mileage.

Anyway, one last piece of advice - run a carb cleaner of your choice every other tank or so. You may also want to look at installing an inline fuel filter to help keep the carb spiffy and clean.

[5th_bike]

Your problem will likely return in about 170 to 210 miles, but now you know what to do.

PS did you ever find the "RES" setting on the petcock?

[mole2]

Zero the trip odometer each time you fill up. As 5th_bike said you can usually go 170 to 210 miles between fill ups. Make sure the petcock is in the run position and NOT the res position. That allows you to switch to reserve to get to a gas station.


:)

[Shearerforce]

All noted....the fuel filter? I will have to google that. Unfortunatly after my last post of excitement I have bad news. The bike ran fine on my test drive. I took the bike to work today aboit 15 min trip amd hit 50-60 and made it fine. I started the bike after work and started on my way home with no problems. I got the bike to 50 mph again and the same thing happened abput 10 mins into the ride...stuttered and gasped for power and shut off. ...This happened on 95....pretty big hwy....But I coasted over to the shoulder and tried to start the bike again. It would not start on the first try. All the electric was still on but the motor just cranked. I turned up the idle screw and it started. I knew it was going to be an adventure to get home despite the trip normally only taking 15-20 mins. The bike literally cut out at speeds of 0-40 like 20 times. I had to stop in a parking lot and leave it for a while because the battery died from me trying to start it so much. I called the guy who I bought it from and he came to pick it up. He is going to look at it for me. but I am still wondering what it could be. I am determined to learn more about my bike and understand the reasons for problens that pop up. Thanks again for all the insight.

[Maggie]

Hi and welcome to the forum! Did you check your air filter and empty the little drain hose from the air box? See if that helps and, if not, the next thing I would do is check the fuel filters in the tank, i.e., those attached to the petcock assembly. I actually had a similar problem with my bike (although not as many engine failures) and after following the same suggestions from the awesome people on this forum, the problem has cleared up.

[k1w1t1m]

I would suggest you have either one of these problems

Condensation in the gas and or crappy gas. You can either drain the gas tank and refill with known good gas or use a treatment like Seafoam. Drain the carb float bowl too.

Alternatively there might be a loose electrical connection somewhere. You might have to spend some time going over the wiring harness looking for chafed wires and reconnecting any connectors along with making sure any screw type connections are clean and tight.

[5th_bike]

Sounds to me like the bike isn't getting enough gas. Next time it cuts out on you, put the petcock on "PRI" (pointing down) and see if that helps. If it runs fine after you put it on "PRI", then there is a leak in the little vacuum hose between the petcock and the carburator.

Don't leave it on "PRI" after you shut the engine off, to prevent a puddle of gas under your bike.