mrbigg

My Feedback: (21)

Anybody ever run a pipe on a .51 ST? I was kind of wondering how much I would gain.

Flyer95

My Feedback: (1)

I have not tried it on the ST51 but on ST90, 3000, 3250 and G4500 and all other 40-50 sized engines that I have tried a pipe on gave me about 1500 rpm more compared to the stock quiet muffler.
Engines in that size that I have tried with a tune pipe are Irvine53, MVVS49, Webra61 and maybe some more that I dont remember. All these engines responded very well to a tuned pipe.

mrbigg

My Feedback: (21)

That's a pretty nice gain. I've always wanted to put a pipe on an engine so I might as well try it on this engine.

Jezmo

I haven't tried it on my China made 51 but I had an older Italian made 51 that I raced on a Scooter II and it gained about 1500 on a pipe. It takes a bit of work to get the header trimmed to the right length though. I think Macs has a chart showing total pipe length measurements on their web site for most engines using their header and pipe combos. That helps getting into the ball park when tuning the length.

mrbigg

My Feedback: (21)

Thanks guys.

flightcrazed

My Feedback: (13)

I have an italian st51 I run a beer bottle on, it is a significant increase over the stock muffler.

Jezmo

Everytime I tried the beer bottle trick it broke. Never figured it out. (Snicker,Snicker,HeHeHe)

BillS

What RPM should one expect without a pipe?

Bill

mustangman177

I use the ultrathrust muffler from performance specialities and I get a noticable increase in rpms. Really brings this engine to life.

Cary