I'm running PA50ii bottom with DR70 kit, boysen kitted reeds, stock carb with 90 jet. Motor suddenly won't idle and has lost power. Idle is surging. I check and cleaned carb but no change checked for air leaks at carb and block, nothing. Anyone have any thoughts.
I had inconsistent idle, fouled plugs and all types of wacky shit on one of my builds. turned out to be bunk electronics resulting in weak and inconsistent spark.
seems like you've looked at everything else might want to check that next.
welch plug? air leak somewhere would be my guess.
For clarification did it start doing this the first time you started it after installing all you upgrades or did it run fine for a while and then start not idling?
If the latter I would also guess wiring - check all connections and make sure they are solid it is also possible that the ignition system is going bad.
If it didn't run correctly right after your install then I would first check the plug for excessive oil residue (improper fuel/oil mix) and make sure you properly torqued down all the bolts for anything you took off. Properly gap you spark plug it maybe the DR kit needs more or less gap, I would ask around for that info. Good luck
Adjust your air fuel mixture screw as well, you will have to lean it out a bit I believe.
The bike ran fine after all the upgrades. It also has a LeoVince exhaust. The idle problem came on after about putting 200 miles on the kit. First it wouldn't stay idleing at lights without goosing it so I adjusted the idle screw and played with the mixture screw. I took it out for a spin went up a nice hill but started losing power. When I got back the idle was real ruff and then it would die. I changed out the spark plug because she look a little black and switched out the 92 jet I had and threw in the 90. There was no difference in the bikes performance and it wouldn't stay idleing for long. I know the headgaskets are fine so I'm not losing it there. I'm at a loss and fear the bottom end seals are shot. But I'm not sure of the symptoms for that.
The manual I have been reading lately for the Hobbit states these things as issues for rough idle. Since you figure the fuel system is OK I'll skip to the electrical and other issues.
- Check your spark plug and/or buy a new one. Properly gap a new plug.
- Check you points for dirt/corrosion and make sure it's gapped correctly.
- They do mention a blown head gasket as a possible cause. You should consider re torquing your head to proper specs since engines expand and contract with use.
- Choked silencer on your exhaust.
The case gaskets if worn usually only cause air leaks which makes for a lean condition since more air is drawn into the case. Since you mentioned your spark plug was dark that would indicate it's not running too lean and probably your issue is with the ignition system. My guess would be the contact breaker points or old plug. I don't know much about the coil but I imagine they do fail eventually that could also be an issue. Hope this helps.
I understand the logic and now suspect it's electrical. Since I already renewed th plug I'll switch out the points with a new set I have on the shelf and see if that clears it up. If not I'll switch out the coil.
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