Worn out throttle shaft?

Hello everyone,

Hopefullly I didn't miss a post about this on here allready. I did do several searches and didn't seem to find anything that quite matched my situation.

Thank you in advance for any help you can provide!

I am rebuilding the motor on my Chrysler Conqueror Shallow Vee and have been informed by my brother that the carbs may be shot.

The motor is a 1971 120HP Chrysler outboard.

As I understand it the engine wasn't running well and they were troubleshooting the issue. When one of them covered the ends of the throttle shaft with their hand the engine ran better and continued to run fine for a short time before the engine burned up the number 2 piston assumably from running lean.

From what I have been told the throttle shaft is worn out and can not be repaired.

Many years ago I used to rebuild carbs all of the time and have probably rebuilt a hundred or so carbs. Mostly on cars although I did do some heavy equipment ones as well. The only carbs I had ever seen a worn out throttle shaft on were quadrajets due to the teflon wearing off and the roughness of the cast surface wearing out the throttle plate and these were repairable with a brass bushing kit that consisted of a drilling an over sized hole and inserting a bushing.

So to get to the point here is this a common problem with the Tillotson carbs or is it likely that my brother is mistaken?

If it is a common problem are there aftermarket carbs that will work? Or is it possible to install bushings to resolve the issue?

Again any help would be greatly appreciated.

Thanks again
x86

Re: Worn out throttle shaft?

Not common at all! Chromed brass shafts on aluminum are excellent bearings and with the small amount of oil from the fuel that works into them, they should last forever.

Sure--if you are accurate, you can bush the castings, or sleeve the shafts id they are worn. Or even build them back up with silver solder--but then you need to turn them true again. If you like to do that stuff. BUT: there are so many carbs around---

If you have the small venturi (1 5/16 diam) WB carbs, find a junker 90-120 and replace them. If you have the massive 1 5/8 venturi TC carbs find any junker Force 120-125 and use them. It's way easier.

Re: Worn out throttle shaft?

Frank,

I kind of figured something like that. Even on regular gas engines without the oil added its uncommon so I was scratching my head a bit. The stock carbs are the WB-13 b/c carbs. It certainly seemed like I could use one from any motor even close and just swap the jets to make sure I'm at the right fuel mixture. I know my step dad used to use starter fluid about every year on the motor for the first start and thats bad for drying out seals and joints so that may have accelerated wear or my brother is just wrong. He is a diesel truck mechanic so anthign is possible. I know that coming from a automotive engine background there are some things to learn that are just different.

Thank you very much for the response!