outa control

My Feedback: (22)

I purchased a used OS surpass engine about 8 months ago and have had no trouble with it until a few weeks ago when it started to lose power at full throttle. A club member helped me adjust the valve tappet clearance, which is located under the valve cover. We adjusted it just like it says in the OS manual and power was restored for a few more flights. The engine started to act funny losing power again like before so we checked the clearance a second time. The clearance was off again and I noticed that the tappet screw head was missing which is located under the rocker arm. I found the screw head had broken off in a perfect circle and slid down the push rod. I recovered the screw head and ordered a new one to replace the broken one. I'm thinking that this is not a normal failure for a motor less than a year old. Is there anything else that I should check or clean out before placing this motor back into service?

Bax

My Feedback: (11)

Other than a good, overall check of the engine, we'd not know what else to look for. Detonation can set up vibrations that could cause the tappen screw and nut to vibrate loose...at least, that's a thing to check.

outa control

My Feedback: (22)

Thanks for your help.

OreoFilling62

My Feedback: (3)

I have an OS .91 in a TF spitfire I just bought, and for some reason every time I top it off with fuel it will run for about 20 seconds, then it will quit on me. I will put a tiny bit of gas in it (till it starts going out the exhust), and then it will run for about another 20 seconds, then quit again. What is wrong?
HELP!

Corey

Bax

My Feedback: (11)

It sounds like the engine's burning only the prime. Is it getting fuel from the tank? You'll have to check the fuel system. Make sure that there are no leaks, cuts, kinks, and so on in the fuel system. Double-check the needles. Make sure the high-speed needle's open about 2 to 2-1/2 turns to start. The idle mixture should be in the center of its range.

The engine should draw fuel easily.