Re: '37 120C running loud

Posted by TxGoat On 2024/2/24 16:01:54

Does the new system have 2 mufflers? It should have 2 mufflers and is otherwise very straightforward.

I don't think anything else would fit, unless it was a 115. If it makes exhaust noise, it is probably leaking somewhere, or the manifold is cracked or has gasket problems.
The pipe should have a hanger back around the bell housing, and I think there is one more behind the mufflers, and one at the back just behind the gas tank.
If the pipe or mufflers touch the frame, it can cause rattles or rumbling sounds. Sometimes pipes and hangers have to be adjusted to get clearance at all running temperatures and when the engine is loaded, which can cause the exhaust system to move into contact with the frame.
The manifold heat valve shaft can leak, and the exhaust manifold has gaskets at the pipe attachment, at the cylinder block, and between the intake and exhaust manifolds.