Tony:

Complete agreement with Bax.

If you want to check it yourself, and maybe save yourself the delay of sending it and waiting for its return, take the rocker cover off, turn the engine until you can see both valves closed, set the crank in position to adjust the valves.

Press the valves open one at a time, if you feel a big difference in the spring pressure you've probably broken one. This is very rare. Be careful as you let the valve close, you can disengage the push rod from the adjuster, making the valve stand open.

Next check the valve clearance. If you find one with zero clearance you might have had an adjuster nut a little loose, Reset the valves and check compression again. This is only if you find a tight valve.

If on the other hand you find a valve loose, don't reset it - you've probably gotten Bax' bit of trash on the seat.

Pull the engine out of the airplane. Hold your ear next to the intake or the exhaust, depending on which valve you found loose. Turn the crank rapidly, if you hear a hiss or a whoosh you have a valve standing open, and probably a bit of trash on the seat is doing it.

Clamp the engine in a stand, pull the plug. Then, using a blow nozzle connected to your air compressor blow in the plug hole while you tap the valve end of the rocker with a plastic screwdriver handle. If it's the intake be sure the throttle is fully open. Often this will knock the trash loose and blow it right out of the engine. Things to watch out for: Be careful with the blow gun, don't damage the plug threads. While tapping on the rocker you can also disengage the push rod, just as you could when pushing the valves open by hand.

If you get the compression back, you've saved the postage cost and the waiting time, if not you haven't wasted a lot of time anyway, and the next step is pulling the head. Under warranty, I'd let Bax and company do the job. They are usually pretty fast, it won't take too long.

Regardless of the result of your testing, get on the phone to Tower (Bax' people) and order their catalogue number BRUG3104 and BRUG3204. Cost is about $5.50 total, you will get the Bru-Line air filter and two spare elements. You won't suck any more trash in. Actually, if you send the engine for service, save a few bucks and let them put the filter in with the engine when it comes back to you.

Hope this helps.

Bill.