YS Carb

evanso1975 · Post by **evanso1975** » Wed Oct 26, 2011 2:16 pm

The throttle shaft on my M38's carb (part SS on page 58 of the ORD-9) is seized solid. I've left it soaking in dismantling lube for the best part of six months, but still hasn't freed off any.

Before I resort to Bubba's style of persuasion

, any tips on the best way to get the shaft out of it's housing? Obviously the throttle valve plate will need removing first, but it looks like there's some type of plug that may need removing (part KK in the ORD-9)?

Thanks in advance,
Owen.

oilleaker1 · Post by **oilleaker1** » Wed Oct 26, 2011 5:35 pm

If you have the bottom throttle body off, heat the cast up red, being careful not to heat the shaft directly. Drop it in a bucket of water. The water will be sucked into the rust between the shaft and body. Light tapping and playing with should dislodge it. I got the roller pins out of a ramsey winch fairlead that way. A 12 ton press would not budge them. They tapped out with a small hammer and punch after the quenching. Water as a penetrant does amazing things! John

Post by **wesk** » Wed Oct 26, 2011 7:15 pm

Careful that throttle body is cast iron. A quick dunk in cold water will often crack them. First remove the throttle plate. Then heat the casting and try tapping the shaft out. You may have to heat the body 4 or 5 times before the shaft comes loose. The extreme measure used as a last resort is to cut the ends and the plate out and then drill the remaining shaft pieces out.

A trick to use when trying to get penetrating oil in a corroded part is to heat the parts then spray the penetrant. Just like sweat soldering a copper joint.

keats · Post by **keats** » Wed Oct 26, 2011 10:09 pm

be careful with the removal of the throttle plate. The two screws are slightly counter punched on after being installed and will easily break off at the shaft. Don't ask me how I know this!!

Post by **wesk** » Wed Oct 26, 2011 11:11 pm

If the previous carb builder did too good a job on staking the back side of those screws then before you break them take a rotary file ( die grinder to some) and grind the staked tail ends of the screws off.

evanso1975 · Post by **evanso1975** » Thu Oct 27, 2011 12:09 am

Thanks for the tips! First off, I'll try heating it up and give it another dose of penetrating lube. I try to avoid the use of big hammers on small essential parts where possible.

Thanks again,
Owen.

oilleaker1 · Post by **oilleaker1** » Thu Oct 27, 2011 5:04 am

The screws come with the more complete rebuild kits. They are not easy to get out after someone twists them off. Mine came that way. Dremel tool time and a 4- 40 tap. Hopefully your shaft won't be too loose after you get it to work. Good luck. John

Headcase · Post by **Headcase** » Tue Nov 01, 2011 10:41 am

No need to take the plug out unless you want to drive the shaft out.
Once you take the plate off and try to save the small brass screws as well then you may be able to twist the shaft in the carb and work some penitrating oil in there. Another oil is acetone and trans mission fluid works real well soak it in that eats the rust. there will be a rubber seal at the end that has the lever that could be the problem too. twist it first once the plate is off.
Good luck.