towershaft/carb sticks?

[noah4009]

I have a 1971 55HP Chrylser. Has single carb. I rebuilt carb amongst other things. I start with throttle at 45degrees. After starting I pull back on throttle and engine continues running high and fast. I went to engine to pull back bar (towershaft) that controlls acceleration. It continued running fast for about 5-10 seconds before idle slowed down. What can I do so towershaft will go back to idle when throttle is pulled back and where did I go wrong when I rebuilt the carb. Seems to stick.

 

[steelespike]

Re: towershaft/carb sticks?

Would be difficult even for a Chrysler expert to know where you went wrong.
Speaking generically disconnect the controls and operate the throttle(motor off in forward.Observe the operation of all components.Most motors have a high idle cold start position perhaps it is stuck on?Try to eliminate components until operation seems normal.

 

[Frank Acampora]

Re: towershaft/carb sticks?

Jeeze, Noah! You sure are having problems with that engine!

When you rebuilt the carb, did you tighten the throttle cam nut too far? even though the throttle cam is carried on plastic bushings with lands it can still be over tightened. The nut should be a self locking type and should be tightened ONLY until there is no wobble to the cam on the shaft. Usually this is just at the point where the nut contacts the plastic bushings.

Second--when you remove the throttle cable does the tower function smootly? You need to check the two nylon bushings that hold the tower to be certain they have not swelled or gotten dirty. That will bind the tower. Also disconnect the timing link from the tower and try to move it. It should move silky smooth. If it binds, then either the magneto carrier is dirty and binding on the plate OR the screws were tightened with the carrier crooked or not properly seated on the plate, thus binding it on the plate.

Of course, before you disassemble anything, you are going to check to see if the throttle cable itself has started to bind--it's not uncommon with old engines. Cure? Buy new Teleflex standard threaded end cables for 30 bucks each.

 

[noah4009]

Re: towershaft/carb sticks?

Hi Frank, Yea having problems. But remember I never did this before and we been thru the head, under flywheel, LU, starter and carb. And I got it running. With your knowledge of course. So I do pat myself n the back. But seems I just need to do adjustment work. Or change parts in that system. Otherwise it now starts and runs smooth, except for this problem. So come on give me a break. I will check everything you said in the morning. Will get back to you. Thanks again, and again and again and so on.

 

[noah4009]

Re: towershaft/carb sticks?

Jeeze, Noah! You sure are having problems with that engine!

When you rebuilt the carb, did you tighten the throttle cam nut too far? even though the throttle cam is carried on plastic bushings with lands it can still be over tightened. The nut should be a self locking type and should be tightened ONLY until there is no wobble to the cam on the shaft. Usually this is just at the point where the nut contacts the plastic bushings.

Second--when you remove the throttle cable does the tower function smootly? You need to check the two nylon bushings that hold the tower to be certain they have not swelled or gotten dirty. That will bind the tower. Also disconnect the timing link from the tower and try to move it. It should move silky smooth. If it binds, then either the magneto carrier is dirty and binding on the plate OR the screws were tightened with the carrier crooked or not properly seated on the plate, thus binding it on the plate.

Of course, before you disassemble anything, you are going to check to see if the throttle cable itself has started to bind--it's not uncommon with old engines. Cure? Buy new Teleflex standard threaded end cables for 30 bucks each.

Hi Frank
Helllllllllllllllllllllllp. LOL Anyway I checked cam nut and its fine and moves freely. I removed cable and tower when in the forward position (accelerating) I bull back manually it is smooth half way then you can feel the bind. It gets hard pulling back. I disconnected the top bar that comes from under flywheel to tower. Now the tower moves free and smooth. I pushed bar that comes from undr flywheel in and out and thats hard. Pushing half way in it gets hard. Whats next? do I remove Flywheel? If so what or how do I clean? Can I spray something up under there and free this?
I removed flywheel and stator. Then cleaned. The 3 bolts that hold down the braker plate had butterfly type clamps that put pressure on the breaker plate. I had to bend them back a little, to relieve pressure. Works fine now. Thanks, you da man.

 

[Frank Acampora]

Re: towershaft/carb sticks?

Now you are getting difficult for me. It has been so long since I have worked on my 55 that it is difficult to remember.

If the magneto plate moves halfway back then gets difficult, it could be due to numerous causes. ONE would be that you are moving it to the cam and opening one set of points--normal. But, as I understand you, moving back would be in the direction of the flywheel rotation and should not cause a de acceleration problem.

However, you could also have a wire binding up, or even a magneto coil binding, so if all else in the system is normal, now is the time to pull the flywheel and check everything under it.

Look for rub marks on the inside of the flywheel and on the coil laminations. I doubt this is the problem, but check anyway. Look for any interference of the magnetos and mounting plate. You may have a longer screw sticking down, or if I remember correctly, the ground wire screw and nut may be causing interference. You should be able to check this wire without removing the flywheel.

Right now, that's all I have.

 

[noah4009]

Re: towershaft/carb sticks?

Not sure if this makes a difference but My 55 is electric coil ignition. Standard. You mentioned magneto. (UPDATE) I removed flywheel and stator. Then cleaned. The 3 bolts that hold down the braker plate had butterfly type clamps that put pressure on the breaker plate. I had to bend them back a little, to relieve pressure. Works fine now. Thanks, you da man

 

[Frank Acampora]

Re: towershaft/carb sticks?

See! When you get old, your memory is the second thing to go--I thought you had said you had a magneto ignition engine.

 

[noah4009]

Re: towershaft/carb sticks?

Well its fixed and thats what counts. I check the forum daily, and all the info I see you give. Believe me, your memory is great. It's just over filled. (LOL)