ORIGINAL: jamesflies
hey guys, i have a super tigre G-90 and bought a perry pump regulator for it. the instructions for the the pump say to drill and tap a hole for the pressure fitting either in the center of the backplate or through the engine mounting lugs. i just wanted to know where the best place to drill the hole is.
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I have drilled and tapped holes in the center of the backplate. I did not use a nut on the inside and I had no problems with this installation. I've done it four or five times on various brands of engines without a problem.
However, later on I began to use pressure fittings either from the engine manufacturer that were the same size as a backplate bolt, or I increased the size of the hole and threads in a backplate bolt of a metric engine to accept a 6-32 pressure tap used for muffler pressure on tuned pipes and mufflers.
I presently own a used HB.61PDP that someone drilled a hole into and through the right hand (doesn't matter which side) engine bearer. This is a good idea if the other two methods aren't easy for you. I imagine that if a backplate screw hole isn't already vented to the crankcase and if the backplate material is too thin (Webra/Super Tigre), the engine bearer location might prove to be the best. But you won't do this drilling job with a hand drill. <G>
I would try to find a way to use the backplate screw hole first.