Just got my engine back from the machine shop after having it stripped and rebuilt, inc gearbox.

Now it bogs out on tick over and wont rev without bogging and cutting the engine. In fact its hard to keep it running in neutral, as soon as I put into first it dies

I have already stripped and cleaned the carb and jets, replaced the air filter and spark plug, added fresh mixture, and checked the reads.

Can anyone suggest anything else please??

Is this sort of behavior expected if the piston is in the wrong way???

Thanks, Jon

KX125 1992

just checked the piston and its in the right way.

Anyone?

Did it run ok before it went to the shop?

Hi nublud, yes it ran fine before. The gearbox was knackered but started and engine ran sweet. Its been in the machine shop for a few months as the gears were hard to get hold of. Spent all weekend on it with no luck, sounds like a fueling problem so will take another look at the float pin but tbh I'm about out of ideas so will be a trial and error of new part, jets, reeds etc. I usually work on cars so I'm not as clued up as most on this site, any pointers would be greatly appreciated
p a while as the gears were hard to come by.

Spend

Do you know if the shop did anything to the carb? Sounds like it might be running too rich, like maybe too large of a jet somewhere. You're right, there may be some trial and error involved. The stock main jet should be a #158 but could be anywhere from a #152-#178 and the stock pilot jet should be a #48 but could be a #42-#52. If the carb was stock, check for the stock jet sizes and make sure your needle is seated and functioning properly. Also, check your float valve again. Check your pilot air screw and your throttle stop screw before you tear everything down. Let us know how everything checks out.

Thanks Nublud, especially re jet sizes, I'm on 16hr shifts until Friday so I'll post my findings then. The carb has been sat in my garage for past few months, only the engine was taken to the machine shop. I've not upgraded any parts in the past 7 months of owning but can't comment for previous owners, I will order stock jets anyway to eliminate any possibilities, also whatever other consumables the supplier has. Update on Fri.

T

Last nights findings were that the main jet is 160, the float valve appears to be working ok. Before I had chance to check anything else a mate brought round a spare coil so we tried that before retiring to the pub. Result= same problem. Kicks up reluctantly and then bogs until it cuts out.

This morning I'll be taking the carb off (again) for final checks before I call the local kawasaki specialist.

It has a 50 pilot jet, (Keihin carb - assuming standard as my mates is the same) and a dyno-port exhaust. All jets inspected again, no blockages, petrol flow is good. Adjusting the air screw makes no difference. Sounds daft but I'm now going to remove the exhaust to make sure its clear and seated correctly. Failing this I have a large lump hammer if anyone needs any KX parts... :D. lol

SORTED IT!!!!! there was loads of something in the exhaust blocking air flow, must have got there somehow whilst on the side in the garage whilst engine was being rebuilt. Runs sweet now.

Thanks

Good job I checked that before calling the kwak specialist. That would have been embarassing. Off to enjoy myself. Thanks for your input Nublud