Worn Solex linkages

[718RSK]

Worked on final engine assembly and setting up the Solex linkages today. I found the linkages on the 1-2-3 bank moving up and down. Taking it off the engine it appears to balls have worn out the inside part of the tube that receives all the pressure from the return spring. Does anybody have experience correcting this?

I was thinking of applying some epoxy and afterwards dressing the inside on the lathe. Don't think this will work as it will probably not be hard enough to take the loads. Other option, which I am leaning towards, is to bore the linkage and press in some thin wall stainless tubing. Any perspectives on this?

[Olivier]

Joris,

I don't know if it's possible to do this in such a small bore, but you should perhaps take a look at plasma spray coating technology.

It's strong enough to repair some heavy loaded bearing surface, so it would probably be just more than enough for this application.

Depending on the meat you have in the tube, a little sleeve might be a good option too.

Olivier.

[stephers]

Check out Partsklassic or Pierce manifolds Both carry new sockets and replacement balls Is it your linkages that re worn or the butterfly shaft?

Thanks, Rick

[718RSK]

Hi Olivier,

The spraying might be an option. Had good results with that when I did my Nadella's and the surface for sure would be a step up in terms of rockwell. I played a bit more this afternoon. I think bushing with an 11x1mm stainless tube is the way to go.

The bore on my lathe is not big enough to accept the linkage so it will have to be a mill operation. Challenge is workholding but I think I have come up with a solution. Going to experiment a bit this weekend and will report back. If anybody has an easier solution I would love to hear from you.

[718RSK]

Check out Partsklassic or Pierce manifolds Both carry new sockets and replacement balls Is it your linkages that re worn or the butterfly shaft?

Thanks, Rick

Rick, the part that is worn is the complete linkage that runs alongside the carb. It looks like repo ones are available but would prefer fixing my originals if only for the fun of it. https://www.carpoint.de/en/control-s...4-68_1116_2047

[stephers]

Partsklassic has both replacement ball and sockets to repair your original linkage

[356rider]

Joris,

Besides the linkage cross shafts and balls, you also have to worry about the plastic ends on the linkage rods going to each carb. I bought new ends and they ended up being as loose as my originals, which was disappointing. This is the biggest flaw in the early 911 Solex system. Since each carb does not have its own return spring it must rely on the entire linkage arrangement having absolutely zero play or you will not get a consistent idle, regardless of how tight the throttle shafts are in the carb bodies.

[718RSK]

Chuck,

My plastic ends are in good shape. My car was only on the road for ten years before it got stored. For some reason the 1-2-3 bank linkage has a ton of wear. No idea why only that bank suffered.

Attached a picture of the wear for those interested. Excuse the crappy shot was not easy to get enough light. Stainless thin wall tubing is on order. Will try and bore the linkage to 11mm today

[718RSK]

Carefully checked the 4-5-6 bank linkage and it was also showing wear but not as pronounced. Bored the linkages today. Setup actually worked. Some slight chatter but dropping the speed helped there. If I would be in the business I would bore and split an aluminium block to hold the linkage more firmly. As soon as the stainless tubing arrives I will bore final size for the interference fit.

[356rider]

Glad your plastic snap ends for the links have no play. Mine didn't have very much, but it takes very little variance in the butterfly closing position to cause an inconsistent idle speed for that carb. Overall my current idle is sorta OK but not rock solid like I'd want. I'm going to try to do a modification to the plastic ends to see if I can tighten them a smidge. Mine also had one of the cross shafts pretty worn. I ended up getting the replacement from Carpoint and it looked and fit well. I kept my original in case I get motivated to fix it like you are doing. Good luck.