High Idle

[russ]

check all passageways are open in carb. mine was like that and I found a blocked passageway, opened with small piece of wire and cleaner , works great now.

[brewsky]

Wonderful!

These are the ideas I needed.
- I checked the o-ring at the air bypass screw....it was missing! I think I may be on to something but I have a bit of a dilemma. My Clymer manual shows the o-ring between the spring and the threads of the screw. This doesn't seem to work. There is a groove just under the head of the screw and I assumed that must be where the o-ring went. Tried the bike with the new o-ring and no difference. I'm not quite sold that the o-ring is installed correctly though. Do you have a picture of an air bypass screw with the proper position of the o-ring?

I still have yet to check that my timing advance has not jammed in the advanced position.

I will go through the list this weekend.

Thank you very much!

Some carbs had 0-ring screws and some didn't.

The ones that did had a deep groove just under the head, the others just a shallow "groove".

Attached pic shows both types, with the ones shown with no o-rings don't get one.

[Wetwilly]

Thank you for the pictures brewsky. I have the shallow groove kind so I guess I don't need the o-ring.

I apologize that I didn't get to the bike sooner but some friends needed help with their mothers handicap access van...

I did, however, get to work on the old bird tonight. I pulled the carb and re checked my passages then I re-assembled it and blew through it covering the hole where the throttle cable enters. There was quite a bit of air that would pass through. So I did a fairly un scientific thing, started plugging holes that would allow air to pass through the carb.

I started with the vent tube...no change. As expected really.
Then I rolled up a bit of paper and stuffed it into the hole for the air bypass...still no change. Ok, now what? I got tired of wrapping my lips around a fifty year old carburetor, though I'm sure that appeals to everybody right? So I capped the air inlet side of the carb and fed low pressure air into it...a flow test so to speak.

I still got, what I would consider, a large volume of air through the carb for this size of engine.

I'm at a loss ladies and gents.

The last thing I can think of is what Rusty posted about a carb that had a slide that was so worn out that it just let the air go past.

Any other ideas I would be open to but I'm ready to start looking for a replacement carb. What kills me is that it ran and idled for me quite well when I first got it a year ago. Now, no love for me. Does anybody know of a good replacement carb I could use...or maybe an exorcist? Hahaha

[brewsky]

No need to look for another carb just yet.....

Make sure the timing and points are set correctly first.

As mentioned, make sure ALL passages in carb are open, and make sure the slide is bottoming out all the way.

Also make sure the air and idle screws are in the right holes.....the one with the "chopped off tip" (air screw) is closest to the engine, and the rounded one in the middle of the carb (idle speed).

Remove both jets, put a flashlight in the carb throat and see if you can see light thru the slow jet opening.

Make sure you can see thru the slow jet and that the side holes are open.

Get a can of spray carb cleaner and spray into the small left hand opening in the mouth of the carb and see where it comes out (wear goggles)

Blowing thru the carb carb throat won't tell much since there are several ways air will escape you won't be able to cap at once.