Intake Manifold O-Ring air leak???

Howdy again. Yet another question. I've got an air leak somewhere in the carbs area. My RPM's want to climb to 3000. I was checking out the intake boots and, I noticed that under the gasket there is an o-ring. On my old ones I decided to try and remove one, just to see what it was about. The thing was as hard as roofing tar on a cold day but, yes there was a metal base under the old o-ring. Is this something that I should have replaced? I've not seen one listed in the parts schematic. I had replaced the gaskets with new ones before I put the mill back together however, they seemed rather thin & flimsy. Do they need a gasket sealant when installing them? Further, the torque for the bolts that hold the intake manifold in place is 4.5lbs which seems a bit light to me to keep out air leaks. I do know enough to put anti-cease compound on the bolts, I've heard way to many horror stories not to heed the warnings of the evil demon Krakabolt :twisted: I'm trying to eliminate the source of the air leak. All my boots are very new eBay replacements that are plyable. My carbs have all new rubber everywhere.

Thanks all
Ken

 

You should inspect the new boots and see if they came with one but they need to be there. You can also use the black high temp RTV to seal them up.

You can do a quick test with an unlit propane torch. Probe the boots with the propane - if it revs more you have a leak.

 

I'm having an air leak somewhere in either my carbs or my intake boot area as well (I think). Best of luck with it, man.

 

Thanks Bill for the suggestion, I'm gonna try to isolate the problem with the propane or maybe some carb cleaner around all of the likely areas before I try the RTV cure. I'll let you know how it turns out.

Cheers
Ken