1986 Yamaha Jog Novice needs help

[30-A rider]

Im somewhat expereinced with 2 stroke motors having raced Mx for years and doing all my own work on my KX and CR 500's. I bought a 86 Yamaha Jog Scooter. Got it yesterdaya nd it will start after about 15 kicks and I have ot gas it to get it to start. Will not idle. Will run and accelerate decent at 1/4 and 1/2 throttle up to 29 mph. Full throttle it bogs, slows and eventually stalls if I dont go back to 1/2 throttle.

So last night I take off all plastics and seat etc and I get a look at carb which is gunked up with black sludge like dirt that has been accumulating for 22 years.

I pull the carb and clean it with carb cleaner. Pull the jet clean it etc, pull out idle speed screw etc and get every thing looking new. It starts easier but still requires a twist or throttle while I kick it over and still will not idle. Same with operation only at 1/4-1/2 throttle and full throttle it bogs.

So after I cleaned carb all is the same except it just starts now on 3-5 kicks instead of 15-20.

If I can get it to idle decent and runn through the entire throttle, plan to do a fresh top end with a big bore kit, but not until I can get it to run decent for a starting point.

Plug is new, fuel line is new.

Any help of suggestions on what Im missing veterans?

 

[30-A rider]

Bump? Come one gentlemen. Over 20 views and nobody has any ideas?

 

[darookie]

I know you have cleaned carb , but the problem you describe is consistent with a clogged jet , I would pull the pilot and main jet and reinspect .

 

[StepVino]

Did you clean the idle fuel passages? There should be tiny passages
from the top of the idle jet well, to just downstream of the throttle
slide.

 

[30-A rider]

Ive done all the above. Not being as novice I have the jet cleaning too for each size jet and ran the appropriate size through all and appear clean. With that being stated Ive gone through this carb 2x and now I cant even get it to start! Spark is very good. Evne though Ive cleaned it twice Im thinking I need to soak the carb for a few days, and maybe replace any and all parts I can such a main & pilot ket, needle & seat etc.

Would you guys recommned this or should I look to just getting a new carb?

Finally any recommendations on where to get these parts ( or a new carb) for the best price?

Thanks for any replies in advance.

 

[haman]

false air

 

[30-A rider]

false air? Is this a sight or are you stating something way over my head? What is False Air?

 

[slevin]

intake leak somewhere ? maybe cracked manifold ? or vaccum nipple rotted out ?

 

[DRXRACING]

Will not idle is also consistent with a failing ignition coil, low compression, plugged up exhaust system or exhaust port.
What I am hearing you say is that the carbureator is perfect and it is not the problem. So we have to go on to other troublesome areas.
Years of sitting could also dry out crank seals, intake manifolds, air filiters, etc.
The engine will run correctly but the basics need to be addressed.

 

[tiba_karotsu]

yes, it is an old engine so your intake manifold & oil seals must be suspect, you could also try checking your reedvalves, they are stainless steel reeds if they are stock, try bending them to seal perfectly against the reedcage.

 

[FUracing8]

I was about to say...........

to follow up on what Tiba just said, all this carb talk and no one has suspected the reeds yet.