Does anybody know if the exhaust mid sections differ between 250 and 350 on m158 onwards. 

The exhaust flange of the 350 and the 250 might not fit in comparision that the only thing I know, all other components are pretty much the same. 

I experienced that difference as I bought a much used middle exhaust from a 198a rebuild it an also (luckily) made the exhaust pipe deattachable to exchange the pipe or clean the hole tube inside easily without opening the middle box, to bolt on ny 199b.

So you might do there the measurements to determine that it fit. (axis of the 4 exhaust bolts in comoarison to the axis of the flange holes if the middle exhaust section). 

The first sections differ between 250 and 350 and the bends can differ slightly. As long as the silencer is the same 

On 1/16/2021 at 11:05 AM, noel063 said:

Does anybody know if the exhaust mid sections differ between 250 and 350 on m158 onwards. 

Differs in what way?  It depends on which aspect you mean and what you want to do

I think physically the actual silencer bodies are the same size model to model although they come off the front pipe at different angles depending on the height of the pipe bend as this differs amongst the 250 models. The 350 models also have different bends

The outlet to the rear silencer on the 250 is a smaller diameter than the 350. 25mm OD against 27/28mm OD

I'm fairly certain that the inner core is the same diameter on 250/350

The flange that bolts to the cylinder has a bigger stud spacing on the 350

Earlier model pipes aren't a good fit on the A or B models as they had the engine raised in the frame so had less of a bend to clear the underside of the tank. A higher bend will be too close or even contact with the tank and the heat will cause damage, especially to a plastic tank

 

Hi Woody

I’m thinking of modifying the front section. I just need a silencer section and wanted to check. Thanks for your help

i would modify central section if you want an improvement.

22 hours ago, nigel dabster said:

i would modify central section if you want an improvement.

Probably will do