Exhaust

This page is still a work-in-progress. Just some pics for the moment.

Click on pics for larger images

The flanges are made from 0.120 stainless sheet. Drilled to the O.D. of the header pipes (which are 1.125" OD with 90deg bends)

Cutting out the shapes with a bandsaw

Assembling the loose pieces to see if they will fit. The pipe from the far side is tight due to a piece of the engine sticking out quite a ways. The 1.125" pipe transitions to 1.375" pipe which in turn matches (almost) the 2-1 collector. The collector is only 0.040 so is lighter and I don't think is stainless 308 like the rest - although it seems to weld OK if you are careful.

To weld or not to weld.... It would be nice to have a detachable joint here. Perhaps like a bikes slipon (shown below).

The weights are 2lb 6oz for the header and 5lb 5oz for the muffler. Not too bad. I don't know the weight of a stock muffler but probably close. I do still need to make a bracket to support the muffler though - will try to keep that light.

At least these are components that should stand up to the salt water.

Final Result

I kept a removable joint in the left cylinder header I am sure welding it would mean I would have to bang on it to get it back to straight after the heat distortion.

Exhaust joint is like that of a dirt-bike. I used some stainless wire-wool and some springs from McMaster along with a strong clamp to squeeze down on the wool

I did end up having to add a 0.120 aluminum spacer though.

Simple muffler hanger with rubber support.

Throttle cable adaptor

While I was working on the exhaust I also replaced the governor and throttle control with a simpler stainless one that supports the Morse Teleflex cable better.