hey sometimes my tb 250 will start making a low, choking sound and start slowing down at full throttle(and sometimes 1/4, 1/2 or about 3/4 throttle) , but if i let it idle for about 10 min it will stop(most of the time). It doesnt do it oftem, but its real irritating when it does, because sometimes i have to go at what seems like 0.0000001 mph back to the start of the trail. Oh and most of the time it does it when ive been riding hard for anywhere from 1-4 hours, and every now and then, it does it from the moment i start it up. Anyone know why it might be doing this?

 

It starts to make the sound when it starts up cold, rite? After it warms up dose it start to go away?
If so it might be piston slap, It just might be time for a top end rebuild!!!



Give me more details can you hear where its coming from?

 

Im not sure if you meant "start up cold" as it being cold outside or like the first start of the day, but ill explain both.
The most recent time it happened was on sunday, it was about 80 degrees here (I live in texas) when I started it up and put it away. It doesnt usually happen right at startup, thats only happened once(explanation at the bottom)
but the engine was defendly warm, I was riding on a short track (realy short, my friend made it in his backyard, it takes only about 14 seconds to do one lap) I would pin the throttle, and out of nmowhere it would make the sound, it sounded like it was coming directly out of the engine, couldnt tell where though, and it started to slow down as if I had put it in neutral. But, if I let up on the throttle, everything would turn back to normal and it would work fine unless I pinned the throttle(then it would do it again, I stopped it, turned it off and let it sit for about 15 minutes, then started it and let it idle for about 10 minutes, and it worked just fine.

The one time it had done it from startup was when it was doing it real bad the night before( I couldnt get it over probly about 1/8 throttle before it started to do it) and I parked it in the shed and went to bed, then I came out the next day and started it up and it was doing the same thing right away just like the night before, I then let it idle for about an hour, and it worked fine from there.

Also sometimes it will do it, I will let up on the throttle and it would sound like it was shifting something inside the transmission, then it would be just fine.

 

Hummm, it slows down when it makes the noise... Here is a test start up your quad stand by it lisen close rev it "but not too high" and when you let off the gas if you here the noise its the top end, Other than that this one has me stumped.....

 

nope it didnt make the noise when I did what you said to do, I think I might just wanna take it in and let my dealer look at it....

 

I would call rick ritter first, He should be able to help he is a nice guy to deal with, He answers the phone 99.9% of the time... You can get his # from his web site www.rittercycle.com

 

how long since you checked the spark plug???

 

check your fuel lines or carb it could be oil build up. it is 2 stroke right

 

yeah, its a 2 stroke

 

i know this might be stupid really but did u ever clean or replace your fuel lines that could be a problem it was on my suzuki it didnt want to run any higher then 3/4 throttle and it was boggin out and i replaced the fuel lines. problem fixed. it could also be your carb. prolly not tho