ORIGINAL: knightmagic
Recently bought used .61 super tigre engine and downloaded manual from internet. Ran it for first time yesterday. Looking at manual this morning noticed there should be a gasket between exhaust manifold and engine but there is none. Question is is it necessary and if it is could I use liquid gasket in a tube or should I find some kind of material to make one. Also very hard to tighten muufler to engine, screws want to come loose should I use lock washers or lock-tite(used lock-tite once on engine and almost could'nt get screws off again.)
As one that has used ST engines for many years, 35 RC years, I will add my thoughts. You say "used .61" so I don't know exactly which model ST .61 you have.
Gasket: If you should acquire the standard ST Fiber gasket, pitch it. Cut one from pop-can material. Easy to do. Take a suitable section, press it over the engine exhaust, get an outline established. Cut the inside with an x-acto blade, then drill or cut the bolt holes. Reserve final trimming of the outside until the gasket is installed, then trim to suit. IMO the aluminum gasket is a must.
If you have a bolt-on muffler, re-tap all for 6-32 socket-head bolts and attach muffler. I have never used any lock-tite, etc, just a small lock washer at the bolt head. If you have the muffler with the round tube mount, then just bolt it on tightly. I've never had a problem with those.