Hi All! I am planning on rebuilding a 30/31PICT carb and was thinking of using Permatex orange hi heat fuel resistant sealant, the stuff in a bronze tube, on the carb base gasket. I was just going to use a thin layer only about 1 mm thick. Anything wrong with doing this?
It says it is fuel resistant. I guess that means it would eventually wear out and could be the cause of a vacuum leak. Any help is appreciated! jplikesm73vwbttl
I don't like sealants on that gasket beacuse it can gum up important ports underneath the carb base. If the manifold plate is reasonably flat sealant shouldn't be needed.
Speedy Jim
Just one word: Chapstick
I've used silicone sealers under carbs for years. The trick is to use a
*very* thin layer in order to avoid the problem of gumming up the ports as stated in another response. HTH, ~ Paul aka "Tha Driver"Giggle Cream - it makes dessert *funny*!
A 1mm layer doesn't seem very thin, does it?
----------------------------------------------------------- Yes. Don't do it.
The gasket under the carb is SUPPOSED to be a one-time-use item. It is made of a compliant material that forms a perfect seal when torqued to spec. The torquing permanently compresses the gasket material (you can see the image of the carb embossed in the material) hence the one-time-use.
Virtually all of the manifold-carb leakage problems brought to this newsgroup are the result of re-using a part that was never meant to be re-used. And the few that were not, were often a case of using the WRONG gasket.
Later model Solex carbs pick-off manifold pressure at the gasket flange to modulate the automatic choke. The proper gasket provides a notch so the passageway will not be blocked. Using the wrong gasket -- or simply installing it UPSIDE DOWN -- causes the choke to stay closed on acceleration, usually killing the engine.
Using any form of sealant here is simply not required... assuming you are using the proper gasket. If you think a sealant will cure an apparent sealing problem, the odds are you've mis-interpreted the symptoms.
So what do you do for a new gasket when you have trouble on the road? Ideally, you should have a spare on-board, along with your spare fuses, tire valves, light bulbs and so on. But if you don't, you should at least have some blank gasket material. Using the old gasket as your pattern, it takes only a couple of minutes to make a new one.
Yeah, I know: nobody does it that way. Just like no one replaces the one-time-use crushable copper washers on the sump and drain plug nor their valve adjusting screws when they become faceted. Too much trouble or something.
-Bob Hoover
*********** No; 1mm is way too much & will definately cause problems. ~ Paul aka "Tha Driver"
Giggle Cream - it makes dessert *funny*!
Well then. I will not use the sealant.
Which side of the base gasket with the notch, goes up? Thanks! jplikesm73vwbttl
No, don't use it. Smear a VERY thin layer of vaseline or chapstick on there before torqueing it, and make sure the gasket is brand new.
~Anthony
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