Homemade exhaust for your old lawnmower

Step 4 Attach the muffler

The original muffler has a stop on it to prevent you from over-tightening it and stripping the threads. Your new muffler will not have this safety feature, so be careful when threading the new unit into place. The engine block is aluminum and very soft in comparison to the steel pipe. Do not use a wrench to thread the pipe into the block - hand tight is plenty.

Once you are satisfied with the tightness and orientation of the manifold, screw the muffler body into it. You have a muffler!

You should now be ready to test the exhaust. Be careful when testing and running the engine!

1) The new muffler is much heavier than the old muffler, and may cause stress damage to the engine block if it is not installed and supported properly.
2) The fiberglass tape may come out of the exhaust holes - be aware of this and on alert in case the engine decides to suck up a strand.
3) The muffler gets VERY hot, VERY fast. Do not EVER touch a muffler after running the engine for more than a few seconds.
4) Please do NOT use galvanized pipe. Only use black gas piping. Galvanized pipe is coated in zinc and when exposed to extreme heat, it could offgas and make you feel very sick. My original attempt was with galvanized pipe, and I got a bit light headed after the muffler heated up for the first time. Also never weld galvanized metal for the same reason.

Please be careful. This project involves extreme temperatures, hot gasses and fast moving parts. Do not rush things and be always aware of where your hands and feet are in relation to the mechanisms.

Comments

[sabre]

i agree... you might be crazy! =)