FL250 lost power

[kleake]

I'm new to the forum, but it appears to have alot of good info and I hope to be on it more. I found it while searching for a solution for my issue.

I've got an 83 (I think) FL250 that was running fine, then all of a sudden it lost power. It does still run, but won't hardly idle, and it doesn't have near the power it had. I used to be able to drift it all the way around my circle drive,,, now it won't even do a donut in gravel. I have pulled the top of the head off and the piston has plenty of play in it so I'm thinking the top end needs replaced, but what caused the sudden loss in power? I do alot of mechanic work, but haven't dealt in 2-strokes much at all. If it is the top end, does anyone have a good source for parts for these old toys?

Thanks in advance!!!

[nutz4sand]

Welcome

You'll have to search for parts. You need to do a pressure test on the crankcase. If you lost a bottom seal on the motor (seals go bad and a crankshaft bearing will tkae one out quick if it fails)

But a crank seal going out will cause a lean condition and the pistons will fry within no time if this happens. Could be the case.

[odypilots]

It could also be a stuck piston ring, causing a loss of compression.

[bainer1290]

eBay has lots of FL250 parts

You should put the head back on and do a compression test to see if it is the top end, if compression is good then I would move onto the crank seals as mentioned above or maybe even check the carb.

[kleake]

I haven't actually done a compression check, but I do know it's way down from what it was. It doesn't take much effort to pull it now like it did. I'm guessing top end, but I haven't known of one to quit all of a sudden, normally I have seen them just wear over time.

[nutz4sand]

A crankcase leak will burn a piston down in seconds. But the piston will show its burnt. Does your piston look ok? Does it have visable damage?

[kleake]

I couldn't see any visible damage looking at the top of it other than I could wiggle it in the bore. I didn't pull the jug yet, which would likely tell me what the problem is. I may tackle that this weekend. I assume I can do this in the Odyssey without removing the engine since it is pretty easy to get to?

[nutz4sand]

Don't tear it anymore apart till you put it back together to do a crankcase pressure test!!!!!!!!!!!!!

If you rebuild the top end and the bottom ends got a leak the new top ends life will be measured in minutes OR LESS!

[kleake]

Makes sense, how do I do a crankcase pressure test? turn crank to bdc, then put some pressure to the vent hose and see if I hear any leaks or is there a better way?

[nutz4sand]

Go to this link an read my second post down. If you still got questions after that just ask.

fl350 engine help...please!