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1835 running issues

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knotsofast

Active Member
Joined
Nov 23, 2013
Messages
31
Location
Tennessee
I can't quite get my engine to run properly. I hope you guys can help out.

What I have is an older HAPI 1835 engine that's been hiding in a barn since the mid 80's. Pusher configuration, 009 ignition, dual Weber 228's. Mechanical fuel pump putting out 3.5 lbs. pressure continuous using ethanol free pump gas, 87 octane. Advanced timing set at 15*, points set at .016, plugs at .025. Compression in all 4 cylinders is 105 lbs. cold, hand propped thru 4 compression strokes.

Issues I have are at idle (1000 rpm), #3 cylinder is sucking thru the exhaust a little. I can feel it sucking up to about 1500 then it quits. Pulled the head and the valve moves nice and smooth, no apparent sticking. I lapped the valves and swapped the #3 and #4 exhaust springs. No change whatsoever.

The engine starts easy and runs smooth up to WOT. Once the throttle is opened up all the way it will run smooth for about 10 seconds and then start loosing cylinders, seems like #1 and #2 just about quit altogether, along with some spitting and backfiring. Back off the throttle and it smooths back out almost instantly.

Thoughts?
 
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