Oldbob

I have an OS 91 Surpass four stroke. This is an earlyversion with the crankcase pressure relief nipple under the crank shaft. Can thepressure from this relief nipple be used to pressurize the fuel tank? Also willthis engine run at full RPM without muffler pressure? I plan on using thisengine on a warbird for pylon racing and the muffler gets in the way.
Thanks for any feedback I can get.

Bax

My Feedback: (11)

The nipple on the crankcase must be vented to the atmosphere. It will not provide pressure. The only way to get pressure is by using a separate tap and a one-way valve with fuel regulator or use muffler pressure.

Oldbob

Bax, thanks for the info. I'll stick with the muffler.