CAN THIS CARBURETOR BE SAVED?
"This week we find our reluctant shade tree mechanic once again tearing his carbs apart after having them hang open on his last ride,
With his motor screaming like a banshee he limped it home and now he's removed his carbs ( once again ) to try to figure out what's wrong."
Ok, I pulled the carburetors and have them on my bench. ( 15 minutes from walking out in the garage to having them on my bench. Ha!)
I then separated the carburetors to try and isolate the problem. And I think I found a clue.
I am not holding the throttle open in this photo, do you think this is a problem? Lol
Alright time to break this one down, but first!
I need me a proper Carb Stick like the one my good friend Robin made!
Feast your eyes on Stick It 2.0! Sorry Robin , don't be jealous, your Stick It is so yesterday!
Took me about 15 minutes to whittle this bad boy.
This works SO good! I'm going to have to make one I wouldn't be embarrassed to leave lying out somewhere! Haha
This is the left side carburetor that came to me with wear on the inside of the throttle body. I suspected that, that my be the source of my hang up. Here you can see where the butterfly has worn into the carburetor body.
To try and remedy this, the previous owner had fashioned a really cool shim out of a peice of beer can which he then wired in place and covered with some sort of black goo.
I removed all that when I rebuilt the carbs and replaced it with a very thin washer that I made.
Thinking that where the butterfly had worn into the body might be the source of the sticking, I took some 1000 grit wet sand paper and WD-40 and very carefully smoothed out the sharp edges in the bore of the carburetor. I wound up with this.
I then carefully blew compressed air through all the orifices.
I do not have precision measuring tools however I took the throttle shaft and held it against a steel ruler from a framing square that I know to be true and checked it for straightness. I checked it in all sides and it layed nice and flat against the edge of the ruler. So using a thin film of white grease on the throttle shaft I began reassembly. I made sure to install the return spring in the assembly so that there would be normal side pressure and then inserted the throttle plate and used the snap the throttle method to center the plate. I loctited the screws and assembled everything.
You can see here , with the back lighting, the wear on the right side. It didn't really seem to adversely affect the way the motor ran.
I tried the throttle action again and while it felt better it still felt like it was suffering from "sticktion" and surprisingly it didn't feel like it was sticking at the point where the butterfly had worn the throttle body, but BEFORE that point. So.... I tore it all apart AGAIN and ran to Ace Hardware to buy some silicone lubricant.
This is what I bought.
From the plumbing section. A small container of plumbers grease, it's a gel almost liquid and it doesn't take much. It's safe on all rubber and plastic. This is some really slippery stuff. I used a Q-tip and applied it on all friction points, anywhere that rubs together including the throttle shaft bores.
( which look to be bronze bushings , but not split and do not look to be replaceable)
Now we're getting somewhere! The action is smooth as butter! When you open and release the throttle it snaps shut nice and quick.
Tomorrow I will put the carburetors back together and reinstall them. Will it work?
I don't know, right now I'm going to go have a BEvERage. Stay tuned.
Bob