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.)

Knight.. : Make sure that the mating surfaces are flat and square then see if they match up correctly when mated. The gasket is not necessary. Tighten the mounting bolts as tight as you can get them, use nylocks if you can fit them in there. Put the stronger (I think that's blue) locktite on the CLEAN threads where the nuts are going. That should hold it in place.

I have a Super Tigre 75 that had muffler problems. The inside of the muffler (the baffle) came loose. They sent me a new muffler and after a few flights it too had the baffles come loose. I opted to a tuned muffler (note the word muffler because they have pipes without baffles and mufflers with) and header. This not only increased the power but I no longer have a plane that sounds like jingle bells when it passes overhead.

DS.

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.

have the tube type bolt on muffler sldo tried to get muffler to slide off exhaust mainfold and it is really stuck tight any suggestions on getting it off so I can cleanit

On all brands of engines that I have used I always pitched the gasket and used red RTV in is place.

use thr red rtv it is made for use around heat.

I had this problem too...

Give it a good spray with WD-40 and put the Manifold in a vice... Now Twist the muffler off...

When the engine is running a lot this area stays lubed and it is normally not an issue...

As with the bolts...

I lost 4 sets of Bolts in Mid air due to them coming loose... This was while using the SuperTigre Gasket...

The answer was not making the bolts tighter... As they eventually snap!

The problem was that the standard gasket was blowing out... Meaning that with the additional space between the manifold and the head the bolts where effectively loose and just worked their why apart...

Answer...

Liquid Gasket...

If you wish, lock tight... But not necessary...

Engine has run for about 50 hours now without fault...

Matt