pulse tube

Stout Racing · Posted: Tue Sep 23, 2008 3:20 am Post subject: pulse tube

What would everyone think about a spacer with fitting to pulse at intake. It will take place of the plastic spacer in place know. This would keep from pulling oil up the pulse tube and slowing the pump pressure. Would be willing to make enough for the enduro race. Around $6.00-8.00 each.
Lewis
_________________
Noran clutches
Max-torque clutches
Jammer clutches
Briggs Dealer
Lifan clone dealer
423-584-6663
www.stoutracingengines.com

Michael Jackson · Posted: Tue Sep 23, 2008 10:16 am Post subject:

Thanks for the offer Lewis. We may have to revist that option later if we can't figure out why some have the oil problem and others don't. I'm one of the ones that don't. From the very beginning mine has been pulsed out of the governor hole with a loop in the line and 14 oz. of oil on a 15 degree motor mount. I have never had to drain oil out of the line nor have I ever seen oil coming out of my pump. We have several who have started pulsing out of the valve cover as an alternate location which is acceptable. For now I want to stay away from introducing any type of modification to the Carburetor or manifiold. That is the reason for the stock airfilter and manifold. Give an inch and they will take a mile! If we start an open class that will be a different story.

John Wehrheim · Posted: Tue Sep 23, 2008 10:33 am Post subject:

Could a Walbro pump harder than a Mikuni pump? Could this be a reason? I use a Walbro and have problems with oil. Only use 14oz of oil too. Modified to go to the valve cover, this helped, but not sure if it has eliminated the problem.
_________________
John
Board of Directors
Sr. 2 Cycle Director

Darrin Tebbe · Posted: Tue Sep 23, 2008 10:50 am Post subject:

I'm pulsing off the top front of the side cover now, and don't have any problems. There is a little pocket there made up from the side cover webbing that seems to keep things in check.

Pulsing off the intake would be a bad idea, since that's the whole red herring that led to the demise of the purple plate animal. The engine builders figured out you could tune intake resonance with the pulse line length and pick up big gains on the restricted motors. On the clones the stock intake box and filter are effectively a restrictor, so I'm sure the same trick would work.

My first setup sucked oil like a pig, but never caused any fuel problems, so other than the worry and annoyance I don't really think it's a big issue.

DT