LOST POWER

Zeppo Stegioni /

Was riding my 2000 Tomos Targa yesterday and I suddenly lost power. Thought I may have heard a little click, like the sound of something breaking, right before I lost power. After it happened, the engine still ran fine and I could even get the clutch to engage at about 8 mph, but there was absolutely no power. Any ideas? Broken piston ring? Fouled exhaust? (but I've had that problem and it never led to total loss of power like this time). Thanks.

Zeppo

Re: LOST POWER

if it runs fine at 8mph the igniition seems to be ok.

check throttle linkage .. choke linkage.. anything else that might have slipped or somehow be limiting carburetor operation or air intake, etc ..

there's no point in guessing about rings .. gotta pull the head and cylinder and check things. A broken ring may be visible through the exhauist port but maybe not.

An exhaust restriction could do it. Maybe something broke loose in the pipe and is blocking it.

More info would be useful.. like is the bike modified or stock.. and what were the conditions when you heard something break... top speed down a hill or just cruising along, minding your own business..

Re: LOST POWER

Zeppo Stegioni /

The bike has not been modified at all--same basic condition as when I bought it in 2001. I was cruising along a flat, open road at about 28 mph when I lost power completely. After it happened the first time I took off the cylinder head, cleaned out all of the carbon deposits, cleaned carbon off the piston top, cleaned and oiled the air filter, checked exhaust port and the pipe--everything seemed fine. The next day I rode 16 miles in one direction in the morning with no problem, then 13 miles the other direction in the afternoon--when I lost power again! I checked the carb by the roadside and everything seemed fine.

So I think it must be the rings (sometimes the built-up carbon forms a good seal and other times it doesn't?), but I don't know how to pull the piston. Do I have to open up the crankcase to get to it? When I remove the cylinder head, there's just the smooth top of the piston and nothing to grab. Any advice on how to do this would be great. Thanks.

Re: LOST POWER

you have to un bolt the head and then take off carb and intake and then make sure the block behing your intak is ready to come off and wiggle it off the 4 long screws and then you must take off the piston with the side clips that hold the middle of the piston on and then your getting into a complicated piece of work, i suggest get a manual, then try this

Re: LOST POWER

Don Pflueger /

what do you mean by "lost power"?

did the engine die, or did it just slow down? next time it does this, loosen the gas cap and see what happens. it may be a plugged vent. it may also be a bad spark plug. carbon does not create a seal. no sense in pulling the top end down until you diagnose the problem and know thats what needs to be done. how much compression does the engine have cold, and hot? what color is your spark plug? maybe the ignition system is failing. check out my thread here and build a spark tester to see if you are losing spark when it dies. http://mopedriders.org/viewtopic.php?t=2075&highlight=cheap+simple+tools

i think you have a fuel problem myself.

Re: LOST POWER

Don Pflueger /

man that was one long confusing sentence.

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