canadian oddy wrote:
Yeah careful what you do here. To much pressure and you will blow the seals out.
1) Remove the exhaust pipe and cap the hole with a plate and rubber seal (use an old inner tube).
In this plate I have a fitting for a low pressure gauge and a fitting to pump air in.
2) Remove the carb and plug that hole -- various items can be used. I made a plastic plug.
3) Plug vacuum hose coming from crankcase for the fuel pump.
4) Make sure piston is near bottom so it is not covering the ports and sparkplug is tight.
5) Put in 10 psi MAXIMUM !!!!
6) If you start losing pressure then spray soap water around to see if you can get bubbles to find a leak.
If I find the post with my test rig I will post it here.
Edit: here are some pics of my test rig. They are old ones and you will also note that I have the fittings on the intake and on the exhaust plate. I prefer the exhaust plate because you can't do the vacuum test properly on the intake side because of the reeds.
Ok, removed the air filter assembly and pulled the carb. Pretty sure I know the source of the air leak. The little screw with a blade in the end that guides the carb piston fell out and a nice big hole for an air leak once throttle is pulled.
Going to tap it out and put a larger screw and grind the end so the piston has a guide, then jb weld it in place. If this doesn't resolve it, then it's a leak test for sure.
Leo