Trottle shaft movement…Help!

Re: Trottle shaft movement…Help!

Harylufa said:
Hi All!
I post a video showing how a trottle shaft moves. I have idle problem and my engine is not a 500 RPM as must be. I smell fuel not burned.

How to fix it?
Can this shaft be modified to avoid any movement?

Any suggestion will be very well accepted.
Thank you.

Hary

https://www.youtube.com/watch?v=_XpEGUqNFk0&feature=youtu.be
Click to expand...
Authentically there was dense wool seal in there as well as a sheet metal "retainer". Both are often absent as many (most) of these carbs have been reconditioned at least once in the past and most guys either don't replace those pieces or simply do not tend to them.
 
Re: Trottle shaft movement…Help!

Looks to me like the lever is loose on the shaft. Possibely stake it?
 
Re: Trottle shaft movement…Help!

Looking at the video I can see two things. 1, the lever is slightly loose on the shaft. 2, the accelerator pump link is a little loose in the lever.

No.2 would not cause an idle problem.
No.1 might.

As the idle is controlled by the lever resting against a stop, and the butterflies are slightly loose relative to the lever, they may be floating.

If I had the parts in my hand I would probably be able to see how to tighten the lever on the shaft.

I'm not going to offer a method as it would probably be judged as not best practice by most other people.

The erratic idle may not be anything to do with the lever and shaft.

If you have it running at idle and press on the end of the shaft with your finger or thumb, does it smooth out or make a difference?

If it does, it might prove the looseness in the fit is causing the erratic idle. Either that or you may have reduced a slight air leak at that end of the shaft.

If the other end of the shaft is exposed, a small lever and light spring would hold the shaft at one end of the loose play.

Mart.
 
Re: Trottle shaft movement…Help!

I could not download the video on my cell phone. Wondering which model carburetor you have. If there is excessive radial movement due to wear on the throttle shaft you may need to replace the shaft and/or the bushings it rides in.

Edit: after viewing the video 1 & 2 comments by Mart are good and I concur with him on those. It is also possible that you have some shaft wear at the bushings and some bushing wear as I mentioned. Maybe Charlie ny will chime in with his opinion on this and some suggestions for corrective action. You could also PM him for some advice.
 
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Re: Trottle shaft movement…Help!

Hi all!

First, thank for watching. I found some shaft that use screw. Can this work?

My carburetor is a Holley 94 15/16.

I will disassemble and make a video with more details.

Thanks
 

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Re: Trottle shaft movement…Help!

Try peening or staking the shaft first (Hitting it carefully with a ball pein hammer to mushroom the shaft and increase the tightness of the fit).

Mart.
 
Re: Trottle shaft movement…Help!

Hey Mart, You have better eyes than me. I caught the accelerator shaft moving but didn't see the throttle plate shaft.
Good catch!
 
Re: Trottle shaft movement…Help!

Hi Amigos!
Ok, I will do that, with a Hammer and see what happen.

Thanks you

Hary
 
Re: Trottle shaft movement…Help!

Mart said:
Try peening or staking the shaft first (Hitting it carefully with a ball pein hammer to mushroom the shaft and increase the tightness of the fit).

Mart.
Click to expand...

Hi Mart!

I did you suggested. What do you think?

https://www.youtube.com/watch?v=KXzBGVOTCcs&feature=youtu.be


I have two different accelerating pump link, which is the correct one?

I have a Holley 2100 94 #51main jets and Idle speed is in this Holley (1 3/4 turn) I read in Manual that must be (1 1/2 turn) at 500RPM.

Can you tell me if I am wrong in something?

Thank for the help

Hary
 

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Re: Trottle shaft movement…Help!

The correct accelerator pump link is the one with a "C" on it. Your idle mixture adjusting screws are OK @ 1 3/4 turns.
Have you checked the fuel pump for a missing or broken return spring? (ticking noise)
Could be a loose valve.


You are making good progress. ,..jack
 
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Re: Trottle shaft movement…Help!

Hi Jack!

I actually am using electrical pump. The ticking noise you hew is from left cylinder head (driver side) that noise is not always, but in video I uploaded can be heard. Perhaps, valves breed adjustment, I have regulator valve lifter installed.

The shorter accelerator pump link is "C" stamped on it, so I will change it.

Thank for reading and suggestion

Hary
 
Re: Trottle shaft movement…Help!

I'm not well versed on the 94s but I do know that looseness of the throttle shaft in its bore of most carburetors creates a vacuum leak that is very near the idle mixing area in the venturi. It will not run correctly unless the bore is repaired either with new bushings for those that are replaceable or fabrication of bushings and reaming the bore oversize for those that are not.
 
Re: Trottle shaft movement…Help!

The throttle shaft is not loose or worn in the bore. The lever was loose on the shaft.
 
Re: Trottle shaft movement…Help!

Just stating facts as I know them. I can't tell anything about the throttle shaft bores from a U-Tube video.
 
Re: Trottle shaft movement…Help!

Any visible wear that allows a vacuum leak at the throttle shaft also prevents the butterflies from making a good fit in the carb barrels. Both affect idle control. Most rebuild kits don't contain a shaft or bushings. If your carb is that worn, that is a good case for replacement, because it is also likely that the idle needles and seats are probably damaged, as well. There are good remanufactured carbs today, along with improved new units That will improve performance, and be alcohol proof, as well.
 
Re: Trottle shaft movement…Help!

Hi all!

I checked the shaft and it is ok, I repaired the leverI did the next checking today.

vacuum gauge: 18mmHg
RPM: 550 (at 500 RPM engine tend to stop)
Idle speed: 1 1/2 turn

My engine was at idle speed (garage) during 20 minutes and not stopped. Perhaps it is solved?

Thank for your time and help

Hary
 
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