Help. Older Motorbike in Thailand, engine keeps getting ...

[Guest]

Have a 100cc road motorbike/scooter. About 15+ years old.

The engine is getting very hot under relatively light loads and in mild weather under short periods of time (20 min). The idle will get very high at stops...the bike gets 'jerky' and engine sounds 'grainy' if that makes sense. It SEEMS almost as if it's driving without oil or the oil isn't making it to the engine... oil level is fine and not old.

The engine was rebuilt about a year back because it started to smoke and overheat badly. Still was overheating and after 10 months or so it started to smoke again and be very unreliable and running super hot, so had it rebuilt it again couple months back. Now smoke gone, but still getting so hot and running high idle and losing a lot of it's power after overheating.

Any guesses to what the problem might be? The clutch IS seeming to have some wear and is 'jerky' sometimes...Could that make the engine work extra hard? Sorry, I don't know a lot about mechanics, but I know I'm tired of having to pay to have the engine rebuilt.

[Guest]

is it a 2 stroke with seperate oil bottle, sounds like the oil pump or strainer need attention as its getting starved of oil.

also check engine oil level.

[Guest]

Hi, thanks, it's a 4 stroke and the oil level is good.

[Guest]

how is it cooled..?

[Guest]

It's air cooled. Here is a picture of a similar model, but mine is older. Even when I drive it pretty slow it gets very hot, starts to idle high etc... and eventually kills the bike.

http://img2.pict.com/ab/9e/c2/3709494/0/1277287675.jpg

[Guest]

is the choke manual, does it switch off with the lever? check for movement at the carb end of the cable.

otherwise

i'd suggest then that the oil needs changing, or that the fuel mixture is off and its running hot,