Hi, Just want to share an experience I had with the propane leak test. A month or two ago, suspecting an air leak due to poor idling and crappy running below 3500RPM, I did the leak test. Since I had MAP gas on hand and not propane, that's what I used. After taping over the air holes in the torch, attaching a 1/2"ID silicon hose, and testing that flammable gas was coming out of the hose, I performed the test on three separate occasions. First cautiously, then by the third test, having not found any sign of a leak, I was laying the MAP gas generously all over throttle bodies and hoses from the cylinder head surface to the air box. No change in RPM.
As you may know since then I have made numerous posts troubleshooting this issue. Today, with the bike warmed up and idling, I sprayed some starter fluid at the TBs and the RPM rose 1,000RPM instantly. I tried the MAP gas again, and now, knowing exactly where the leak is I could say that there was some effect from the MAP gas, thing is the change in RPM was largely masked by the crappy idling. With starter fluid that's not an issue.
If your bike is runny poorly and you suspect an air leak, I recommend starter fluid. A little dab'll do you.
