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Carb rebuild reinatall questions

rockwoodrv9

rockwoodrv9

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I had my carb rebuilt and the new float installed. I reinstalled it and I am having difficulty pushing the throttle lever from the cockpit to full throttle. I can physically move the lever to full with my hand but not with the cable. I did have to take the cable support loose to allow me to remove the old gasket so I am not sure if the carb throttle lever is too tight or I have not got the cable reinstalled correctly.

My question is - should the throttle lever be easily moved from closed to full open?

When I use my hand to move the lever it is easy then gets tight. I cant remember how it was prior the rebuild. Here are a couple pics to show the issue. I think it should easily move from closed to open but wanted to check before I send it back to the shop.

Thanks.
 

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It should move fairly easy. Have you put a little marvel mystery oil on the accelerator pump shaft to help lube it up. New seals can be sticky until properly lubed and worn in. Also, did you lube up your rod eye and bolt with some good high temp grease? I would also use the outer hole as it has more mechanical advantage. IF you can disconnect everything and it all moves freely, then you put it back together, it is somewhat binding, it's in your connections and setup.
 
What is the sequence of the hardware connecting the rod end to the throttle lever?

I.e. thrust washer(s), rod end, thrust washer, castle nut?

If disconnect does the throttle cable move freely, and does the throttle level move freely?
 
The throttle cable moves easily and smooth. The lever on the carb itself is difficult to move the last 25% or so. I will try moving to the end location on the lever to help with the mechanical geometry. Is there a way to live the carb system itself?
 
rockwoodrv9 said:
I had my carb rebuilt and the new float installed. I reinstalled it and I am having difficulty pushing the throttle lever from the cockpit to full throttle. I can physically move the lever to full with my hand but not with the cable. I did have to take the cable support loose to allow me to remove the old gasket so I am not sure if the carb throttle lever is too tight or I have not got the cable reinstalled correctly.

My question is - should the throttle lever be easily moved from closed to full open?

When I use my hand to move the lever it is easy then gets tight. I cant remember how it was prior the rebuild. Here are a couple pics to show the issue. I think it should easily move from closed to open but wanted to check before I send it back to the shop.

Thanks.
Click to expand...
It could be that the throttle arm on the carb needs to be reclocked.
The arm and stops are held together by the castellated nut. If you look you will see that they are held together by saw tooth edges.
To do this disconnect the cable and pull the throttle back to what would be the idle position then clock the arm and see if you get more travel.
Moving the connection out to the outer hole will make it worse.
Also, there is an AD to safety wire these together in case the cotter pin fails.
Good luck
 
rockwoodrv9 said:
The throttle cable moves easily and smooth. The lever on the carb itself is difficult to move the last 25% or so. I will try moving to the end location on the lever to help with the mechanical geometry. Is there a way to live the carb system itself?
Click to expand...
Even without the cable attached? Something would then be binding.
The reference to the Acc pump side might yet apply.
 
I think reclocking the lever could be the trick. I have an engine guy coming to the hangar tomorrow and hopefully will get it figured out tomorrow.
 
rockwoodrv9 said:
When I use my hand to move the lever it is easy then gets tight. I cant remember how it was prior the rebuild. Here are a couple pics to show the issue. I think it should easily move from closed to open but wanted to check before I send it back to the shop.

Thanks.
Click to expand...
Typically when they rebuild a carb, they have to tighten up the bores that hold the throttle shaft, as this interface gets a lot of wear that creates vacuum leaks. They do this by knurling the bore or putting inserts in. If the shaft rotation is getting tight part way through the travel, they must have done something wrong in that process. It should be relatively free moving from end to end. A small amount of drag on a fresh overhaul is expected, as it gives you a longer life. But it should not be tight. The cable will apply some side loading to the shaft, so that could make the issue worse than what you feel when doing it by hand.
 
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Take the cable off of the throttle arm and see if the throttle lever moves easily by hand: if it does the problem is with the cable positioning.
 
I found the issue today. The rebuild carb has a different arm on it and it binds with the bracket. I had to grind part of the bracket and arm to make it move without binding. It took me 2 times installing and grinding to make it work. Now the throttle lever works fine.

I didn’t know there were new parts on the rebuild and they are slightly bigger and rubbed on the bracket.

The cables moved freely all the time. That was the crazy part.

Thanks for the suggestions and help. I still have to adjust the throttle cable but it now has full movement IMG_1259.jpeg
 
This is the area I had to file down to allow free movement of the throttle. They must have replaced the arm and lever on the rebuild and it is slightly larger. it was very difficult got me to see when it was installed. Now I feel a little stupid for not noticing it but happy my carb is back on with both cables working properly!
 

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rockwoodrv9 said:
This is the area I had to file down to allow free movement of the throttle. They must have replaced the arm and lever on the rebuild and it is slightly larger. it was very difficult got me to see when it was installed. Now I feel a little stupid for not noticing it but happy my carb is back on with both cables working properly!
Click to expand...
Looks like they forgot the cotter pin. Don’t want that arm falling off.
 
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