I put the #48 in and seems to running much better, no bogging. I also performed a leak down test on it today, here are the results. Pressurized to 7 psi. at bdc after 2.5 mins. it dropped to 6.5psi., 6.0 psi. @ 5 mins, 5.5 psi. @ 8.5 mins, & 5.25 psi. @ 10 mins. Is a 1.75 psi. drop at 10 mins a significant loss ? I sprayed everywhere with soapy water during the test, exhaust plug, carb boot, sparkplug, etc. and didn't see any bubbles. Am I correct the test has to be done with the piston ant bdc ? John.