Chain fell off now won't start, and I hav spark 250r 2nd gen

[jacobfour]

Chain fell off like 3-4 weeks ago and killed motor I was just in like 2nd gear when it happened. 3-4 weeks later got a new chain on put fresh gas in new spark plug gapped right and now won't start I took plug out and kicked it over and I have spark. So to me its fuel or air related. #money pit #fed up.

[azhondagrl]

maybe it gummed itself up in that time....if you've narrowed down the fact that it has spark then I'd move along to fuel. clean the carb out, just cuz you used fresh gas doesn't mean it doesn't have something sitting inside the carb preventing it from getting the fresh gas flowing.

[Racer-X]

Did you try to start it with the old plug in it? Or starting fluid?

[jacobfour]

Did you try to start it with the old plug in it? Or starting fluid?


Yep and still nothing. Maybe pilot system or something is plugged up. I'm gonna tray and clean it a little better again!

[atc300r]

Check your flywheel key it may have sheared when you stalled it.

[jacobfour]

Check your flywheel key it may have sheared when you stalled it.

That's what I was wondering if somehow when chain got caught n front sprocket and killed motor if somehow timing could be off or woodruff key broke. I'm gonna check today.

[tri again]

I know nothing about 2 strokes but if a lawnmower
flywheel key is 'dented' a few thousandths, they will NOT run.
I'm also not sure where they get their spark timing from.
Some cam sensor like a 4 stroke?
Magnet on the flywheel?
EDIT: sorry, no cam on a 2 stroke.
but there may be a ignition timing sensor somewhere else.

Sudden stop may have acted like hitting a rock with a lawnmower?
shocking something off kilter?
Hope it's a free and easy fix.
Pls let us know what you find.

[tri again]

Yep and still nothing. Maybe pilot system or something is plugged up. I'm gonna tray and clean it a little better again!
Really should have tried to spit with start fluid.
Thinking timing is off or like axhonda said, could be old gas, varnish or semi flotation carb crud
trying to ruin your day.

[jacobfour]

Really should have tried to spit with start fluid.
Thinking timing is off or like axhonda said, could be old gas, varnish or semi flotation carb crud
trying to ruin your day.

Ive cleaned the carb 3 times. Tried fresh gas, checked woodruff key not sheared off, timing stil at proper marks idk what the hell. Il I know is no problems starting chain fell off stuck n front sprocket killed motor spark plug good and new and properly gaped I had a little spark too so idk. The floats work the needle isn't stuck.

[atc300r]

Is your plug wet when you take it out. If so your crank case may be flooded with fuel.Have you tried towing it or pop starting it.

[jacobfour]

Is your plug wet when you take it out. If so your crank case may be flooded with fuel.Have you tried towing it or pop starting it.

I have not tried yet but I do suppose that could be it I have Ben going through jetting proccess for the second time never could get mikuni carb jetted right so got a stock khein and I had been really rich at times I had fouled some plugs during this long drawn out proccess so it might be flooded crank case. I guess I will take spark plug out and exhaust off for a while to help it evaporate out a little.

[tri again]

so? what triggers the spark timing on a 2 stroke?

[jacobfour]

flywheel rotates around the stationary stator and as long as the fire mark on the flywheel is lined up with the mark on the stator every time it rotates by that mark it sends charge up to cdi and then to igniton coil. is my understanding of it.

[jacobfour]

Don't want to admit this but I took flywheel off and the crank or woodruff key is not sheared its fine put it back on install every thing make ridiculous adjustments with idle adjustment screw and give it tons of air and finally get it to run but its running really rich and finally boggs down. Finally decide to check carb again to see about ordering different pilot jet and to lean it out and I'l be damned if the pilot jet wasnt even hardly screwed in. I guess somewhere in the proccess of cleaning the carb 3 times and changing main jets out I didn't screw the pilot jet in all the way it was basically just sitting in there so it was just letting tons of fuel in and flooding the engine, ridiculous! screw the damn thing in and braaaaap. it fires right up. got new chain on took it for a spin and the chain stayed on thank god. now I can go back to setting needle clip and main jet. just about got it dialed in, only took me about 365 days and tons of $ and cuss words and cold beverages but whos counting. I've learned a bunch and if theres any other nubees out there like me just keep at it and learn as u go u will eventually get it just might take u longer and cost more money like myself. I checked manual and I believe it had chain slack at 3/4"? I have it at 1" I dont want it too tight? any thoughts on how tight to run chain?