1959 Rapier Carburetor Idle

[husky drvr]

I usually give links like that much sooner. "Sorry 'bout that, Chief."

Since your sII isn't in that manual and you were asking detail, instead of system questions, I didn't realize you might not have those links.

You're still welcome to ask questions.

Have a good day,

 

[Chrisp Rapier]

My carburetor woes continue. I never got the idle to step down enough and I could not balance the carburetors. I have yet again an air leak around the rear carb spindle. I have also developed a drip down the barrel of the front carb after shut off. I am assuming it must be a float/shut off issue. Perhaps something else. I know it was not happening before but the fuel filter I installed under the car was full of lots of sediment.

I guess I am removing the carbs for the umpteenth time.

 

[bernd_st]

Don't give up on your good old Zeniths please. Lots of sediment in the fuel filter doesn't sound good. You may need a thorough fuel tank clean up. For the carbs pls. post some pictures here - will try to help based on those...

 

[Chrisp Rapier]

Don't give up on your good old Zeniths please. Lots of sediment in the fuel filter doesn't sound good. You may need a thorough fuel tank clean up. For the carbs pls. post some pictures here - will try to help based on those...

I will keep fighting the good fight. The Zeniths ALMOST are working well. The gas tank was not great. But it was not all rusted but it did have rust on the top side with pin holes that I brazed. The nice thing about the tanks are that when you remove the gage sender, you get a pretty good look and access inside. I cleaned it out real well but the baffles inside block access the the sides. Inside the tank was a bunch of small stones that were stuck to the tar residue from dried up old gas.There was even a small plastic toy inside the tank. I think where ever the car sat children were opening the tank cap and dropping crap inside.
I have a new temporary fuel filter in place and I will see if that gets all junked up too.

 

[bernd_st]

Good luck for cleaning the tank further. With all those issues you describe it appears to need further attention.

The air leak around around the rear spindle and the idle stubbornness also do require attention. Fuel dripping to be cured as well. You better inspect your front carb float valve for proper shutting. The valve needle tips do wear specifically on "dirty" fuel. Perhaps there is sediment in the float bowls too. This may also be the cause of blocked or at least partially blocked idle channels...

 

[Chrisp Rapier]

Good luck for cleaning the tank further. With all those issues you describe it appears to need further attention.

The air leak around around the rear spindle and the idle stubbornness also do require attention. Fuel dripping to be cured as well. You better inspect your front carb float valve for proper shutting. The valve needle tips do wear specifically on "dirty" fuel. Perhaps there is sediment in the float bowls too. This may also be the cause of blocked or at least partially blocked idle channels...

You are very correct. I examined the float needle. It's badly deformed. I replaced it with a much better used one, I had on hand. The bowl had sediment on the bottom. Hopefully the front carb is sorted out. I am working on cobbleing together a better spindle for the rear carb. I have to extract a broken off needle screw from a spare I have. I am not doing anything with the tank other than the new filter I put in place. If that stays clean then all is well. If not? Then I will have a go at the tank some more. Thanks for the accurate input.

 

[bernd_st]

Well, spot on. You may also inspect the needle seat with a bright LED lamp. It may have worn too. If you exchange the valve better to exchange the brass seat too. In case of light abrasion some guys were successful by lapping the valve in ( with engine valve grinding paste, but must be done with both bits outside of the carb). On a side note your main body top sealing surface seems to be also uneven, but can be adressed later...

 

[Chrisp Rapier]

Well, spot on. You may also inspect the needle seat with a bright LED lamp. It may have worn too. If you exchange the valve better to exchange the brass seat too. In case of light abrasion some guys were successful by lapping the valve in ( with engine valve grinding paste, but must be done with both bits outside of the carb). On a side note your main body top sealing surface seems to be also uneven, but can be adressed later...

I did not lap the needle into the seat, nor did I replace the seat. All I did was polish the seat with a Q tip in a drill with some tooth paste as the abrasive. I also blew out the passages and cleaned the idle jets on both front and back carbs. Curiously enough, the rear carb was clean inside. I put in a different throttle plate housing. ( Do not know what the term is) And a different spindle. It's not great. I put it all back together and started the car. It was the end of the day and did not dial it in yet. It does seem that the carbs are more balanced already though just judging by palm over the barrels. Also the front carb is no longer flooding, so the float assembly is working properly and the garage no longer smells like gas.

 

[bernd_st]

Sounds good progress with appearantly the most urgent topics cleared. Like the Q tip idea with tooth paste
May be able to help with a repro throttle spindle ...

 

[Chrisp Rapier]

Sounds good progress with appearantly the most urgent topics cleared. Like the Q tip idea with tooth paste
May be able to help with a repro throttle spindle ...

The throttle spindle is half the problem. The other half is the wallowed out throttle spindle hole in the housing. It's funny because I have six carburetors. You would think I could manage two good ones out of six.

How can you help me with a repro spindle?

 

[bernd_st]

All Zenith spindles are more or less worn that‘s why I did a repro run. Never saw the housing or the casted spindle bush worn in all those rebuilds I did over the years. Are you sure about it’s only half the problem ?

 

[husky drvr]

because I have six carburetors. You would think I could manage two good ones out of six.

Yes, I would believe finding unworn parts is a problem. The set of Zeniths from my father's sII Rapier are very well worn and leaked badly. We installed them in the Husky for a short period with the sIV Alpine engine. Those carbs were taken out of service before my Dad bought the Husky in early '64. The Rapier died due to an engine failure I THINK was due to the dealership being unable to keep the crank pulley tightened until total failure. They let him salvage pieces and parts before scrapping the car. So those carb's had been in service for less than five years and were already very badly worn.

Just a thought,

 

[bernd_st]

My theory is the Zenith throttle spindles were installed without using any grease. Furthermore and that can be regarded a real design flaw they were only bushed on one side. So in fact the soft brass spindle material wears rather fast. Perhaps also the lever arrangement on the Alpine/Rapier puts heavy loads on the spindle ends…

P.S. Wrecking an engine because of loose pulley is a real nightmare. Have seen a couple of loose pulleys over the years. Another Rootes design issue especially when the Workshops disregarded the proper and extremely high crankshaft nut tightening torque. However it always starts with an audible „knocking“ noise…

 

[Chrisp Rapier]

Sounds good progress with appearantly the most urgent topics cleared. Like the Q tip idea with tooth paste
May be able to help with a repro throttle spindle ...

Well you were correct again. The float needle seat was probably not sealing off properly. I replaced the seat with another one on hand. I am not sure if this has solved my float bowl issue. The reason I am not sure is because the act of changing it seems to have created a new problem.

Everything was running well before I changed it. For the first time I was able to balance my carbs and reduce my idle. The rear carb that had the spindle problem is now good. It adjusts properly. My front carb however will no longer adjust properly with the mixture screw. I did not remove the front carb to replace the seat. Nothing should have really changed. Now the car is runny badly, stalling out at the stop sign. All I can think is there must be an air leak created by removing the top of the carb.

 

[bernd_st]

Pretty weird. If I were you would switch back to the previous seating and check whether the iseue is fixed. Can't realy believe you created an air leak unless the top seal got damaged...

 

[Chrisp Rapier]

Pretty weird. If I were you would switch back to the previous seating and check whether the iseue is fixed. Can't realy believe you created an air leak unless the top seal got damaged...

The gasket is not a new one, so it could be that. When it is not hotter than hades here I'll go spray some carb cleaner around it and see if I get a reaction. If not I'll change out the seat again.

 

[bernd_st]

The seat and the needles were originally sold in pairs. I never quite figured out why, but appearantly there must have been tolerances...

 

[Chrisp Rapier]

The seat and the needles were originally sold in pairs. I never quite figured out why, but appearantly there must been tolerances...

Given the crazy amount of wear that was on the needle I replaced, there either must be a lot of force generated by the float configuration or the metal compound must be particularly soft.

I have valve lapping compound but I cannot imagine how I would lap something so small.

 

[husky drvr]

The gasket is not a new one, so it could be that.

There is a vacuum channel that runs to the carb top to support the use of the "power valve" system.

Obviously, that channel runs through the thick, spacer gasket between base and carb body.

Both would be possible places to check.

Just a thought,

 

[Chrisp Rapier]

There is a vacuum channel that runs to the carb top to support the use of the "power valve" system.

Obviously, that channel runs through the thick, spacer gasket between base and carb body.

Both would be possible places to check.

Just a thought,

When I replaced the float valve seat, I only removed the top part of the carb while it remained on the manifold. Since it rain well before this I presume the thick spacer between base and body is not the problem. I suppose this could be blocked above that, though. The accelerator pump (power valve) is working well when I give it the gas. I can hear it kicking in on both carbs. With engine off I get a good spray from both.