So Close! Carb problem????

[gentlemanjim]

How black is black? A pic will help. Do they foul and not fire? Too rich is better than too lean. My left plug looks a bit sooty and the right looks nice and tan. Bike runs awesome. No decel popping, crisp throttle response. So I don't look a the sooty plug and don't care. Mixture screws won't alter the jetting other than at idle. You might closing them down until the idle starts to drop and surge then back them out until you get a smooth idle. Let us now if that helps.

 

[Socopunk]

Is Black As Night too black? These plugs have less than 2 miles on them. Left plug was wet with fuel and this is the right one. I accidently wiped off some of the soot on it. gentlemanjim are you talking about the Mixture screws or the idle adjustment screw? I think i'll do the dead cylinder method again, just in case, but would like if someone had a step-by-step on it cuz I got a nice little jolt while holding the plug to ground on a engine fin.

 

[inxs]

- run ' dead cylinder ' through the search function in the tool bar above and see what comes up-about a page and a half of entries...have a good read

 

[Socopunk]

So I've searched and I'm doin' somethin':

1. Start Bike as normal
2. Let warm up with fan on engine
3. Have 3rd spark plug ground to side of engine.
4. Have idle set slightly above average.
5. Remove plug wire from plug on one side.
6. Connect to spark plug that is grounded to engine
7. Get the everloving S shocked out of me while trying to push plug onto plug wire.
8. Wonder if that is normal, or if I'm missing something.
9. Look in the kitchen for thick rubber gloves.

How am I doin' so far?

 

[inxs]

- do you have vacuum barbs?...makes it easier

 

[gentlemanjim]

Start teh engine with on e plug out and grounded. Don't pull the wire while running and switch plugs.

 

[bloodthirstysystem]

those plugs are pretty dark.. i get shocked if i pull a wire when the engine is running.

before setting the idle mixture you have to first set the cam chain, timing and valves. it will never idle smoothly if these aren't done, meaning you'll never get the mixture screw set right.

-pull the hose(or cap) off the vacuum barb on the carb holder.
-set idle mixture screws to factory spec.
-set idle as low as possible, then turn the mix screw 1/8 - 1/4 turns in either direction.

you'll hear the motor either slow down (starving the idle for fuel or air), or speed up (good). find the spot where it idles fastest. then do the other side.

 

[bloodthirstysystem]

you should put B7ES plugs in too..

 

[cooltouch]

before setting the idle mixture you have to first set the cam chain, timing and valves. it will never idle smoothly if these aren't done, meaning you'll never get the mixture screw set right.

+1 -- All too often this basic step-wise process is overlooked. I would add checking head bolt torque as well. So, in order: head bolt torque, cam chain, valves, points (if you got 'em), timing. And only then the carbs.

 

[Socopunk]

Great! I have since put in the correct plugs. Thanks for the info guys. I'm gonna go through the whole check this weekend.

Gentleman, that's where i was going wrong. I will try to start with 2 plugs in and 1 plug wire to a grounded third plug instead of the one in the motor.

bloodthirsty and cooltouch - I will go through that checklist you guys made as soon as I put the bike back together. I yanked the whole butt end off to check for wear on sprockets and such. Nothing. Bike is almost 40 years old, but it only has 2100 miles on it!