Tuned pipe length for K&B 7.5cc inboard?

[Greg Moss]

I'm just setting up an old K&B 7.5 cc 9181C (front exhaust, rear induction with a bastard needle valve position...) and a Macs Muffled pipe (1349), and I wonder if anyone can give me a heads up as to a rough initial length for the pipe?

Thanks in anticipation

 

[FloridaScaleBoater]

Whats it in,,,,Boat type??

 

[Greg Moss]

Mono with surface drive

 

[Kez]

I would put the initial length at 10.75". Then start shortening 1/4" at a time.

 

[FloridaScaleBoater]

Mono with surface drive

10-3/8 to 10-1/2" should get ya going

 

[Greg Moss]

thanks guys.

That'll fit. The old Macs header is very long... Now at least I've got a place to start.

Cheers