Super B Gone NUTS

[MNicholson]

Went for a ride today, a short one, about 50 miles. On the last ten my idle was rediculously high and my idle adjuster screw didn't change it a bit. I have a super B (no accelerator pump) and was able to adjust the idle in the past couple of days.

Any ideas what would cause a crazy high uncontrollable idle?

Super B
69 xlch ironhead
.068 main jet
.0295 intermediate jet

[Guest]

Is the butterfly closing properly? How old is the carb? If the holes for the throttle shaft are worn it could be rebuild time.

[spidr]

Sticky cable?

[RustyShackleford66]

Air leaks at intake manifold seals or throttle shaft.

Advance unit not retarding at low RPMs

[RetroRob]

Sticky cable?

Look for a kink in the line

[MNicholson]

@ARBY
the butterfly is indeed closing properly. I rebuilt the throttle shaft last week. This is an old super B so I couldn't replace the throttle shaft holes with the shims that came with the rebuild pack.

definitely not the cable.

Would a small air leak through the throttle shaft holes cause an insanely high idle (i'm talkin full throttle sounding) I doubt it would cause that much of a problem.

[MNicholson]

Air leaks at intake manifold seals or throttle shaft.

Advance unit not retarding at low RPMs

You think this could be a magneto issue?

[GermanG]

You think this could be a magneto issue?

The magneto does not have an advance unit. You have to advance and retard it by hand. Makes kick starting much easier.

What rusty says might be right! There is an air leak between manifold and cylinder heads, either the clamps are loose or the manifold o-rings are damaged.

[MNicholson]

Well figured out the bad news. Both of the bolts holding the butterfly in place broke loose their locktite and went for a ride. I found one in the manifold... the other one

sucked into an intake valve and is bouncing around above my piston?

got shot out the exhaust pipe?

we'll find out i guess.

[13clicks]

Well figured out the bad news. Both of the bolts holding the butterfly in place broke loose their locktite and went for a ride. I found one in the manifold... the other one

sucked into an intake valve and is bouncing around above my piston?

got shot out the exhaust pipe?

we'll find out i guess.

Pull the spark plug and fish it out with a magnet on a stick...

[sportyguy]

Damn I better double check mine! Gone nutz or a screw loose?????? Looks like you were right all along!

[MNicholson]

Damn I better double check mine! Gone nutz or a screw loose?????? Looks like you were right all along!

almost makes me feel better!

i still have compression in both cylinders and the walls look alright. the tops of the pistons are both dinged up and the bolt is nowhere to be found. looks like it shot out the tail pipe.

now onto the damn air leak at the throttle shaft...