250 died on me today. what happened?

i had just gotten back from an hour of riding and my step-brother comes out with his new pipe on his yz125 begging for me to come out again with him so he can try it out. so i go along and down the trail the thing starts loading up on me but when i hit the gas it bogged. i come to a stop and it wont start. i let it sit for 2 minutes, kick it and it runs fine for about 5 minutes then begins to do the same thing. so i decide im gonna head home. it runs fine for another 300 feet then finally loads up, bogs and dies and i had to be towed home by a quad via an old hose.

what gives? it's almost doing the same thing it did when my carb was clogged. good gas. sketchy pre-mix (halvoline tw-3) but seems okay. what are the causes for loading up and bogging like that? it was just sitting there and idling like BWA BWA BWA BWA BWA. then when id hit the gas GURGLE BLEHHHH dead. :thumbsup:

sounds like plugged jets

you ran out of gas! No seriously, re-check the carb.

Put in a new plug, check the carb again and then if that dosen't work unhook the kill button, sometimes they cause trouble. Is the compression good? A fouled plug will do that sometimes so try that. Ed

I would also say fouled plug. I know my 2 strokes were always touchy on what kind of gas and premix I used. Once I found a combo that worked I would stick to it. Otherwise you will foul plugs all the time. One thing that always worked for me was half race gas half super unleaded.

I would also say fouled plug. I know my 2 strokes were always touchy on what kind of gas and premix I used. Once I found a combo that worked I would stick to it. Otherwise you will foul plugs all the time. One thing that always worked for me was half race gas half super unleaded.

I believe your supposed to JET the carb!

well ya that to

plugs gonna be the first thing i check. but usually when i foul a plug it just dies. ive never seen it load up and ping so loudly.

Pinging and loading up, maybe bad gas, water and oil steetling to the bottom of the tank and trying to keep running. Or maybe the black box going bad. Just some thoughts. Good luck Ed

i would check the carb, then check compression

i had the same problem. turns out my main jet fell out into the bottom of my float bowl.

i was having similar problems with my 250, mine would load up when your not on the gas and the plug would foul, I did my reeds and it ran perfect after that, i used Boyesen power reeds

If it was running fine before, I would suspect either something broke (reeds,etc.) or something got clogged (jets, plug). I wouldn't change any settings to compensate for it. Start at the airbox and work your way in.

one time me and my friend went riding and the same thing happened to his 99 yz250. Turns out a small fall earlyer caused the spring holding the exaust tight against the engine fell off and the exaust gasses were leaving directly out of the engine. When that happened his plug fouled so even after we fixed it it wouldnt run. but i dont really know much about 2 strokes so i dont really know.

I would check all the same things these guys said and if you still have the same problem I would unfortunately suspect a serious problem with the cylinder and piston. I had a buddy that had the same thing happening to his TM and when all was said and done he got home pulled the pipe to look and sure enough the piston had pertty much exploded the skirt and destroyed the cylinder wall. But he ended up not having hardly any compression either. So if you still have good compression that is probably not the case.

found the problem. totally gunked and clogged petcock/fuel filter. took it out, bathed it in carb cleaner. added some carb cleaner to a new tank and its running crisper than ever before.

It always seems to be the dumbest things eh?:thumbsup: or the things you would never think to check..

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