puzzle
Senior Heliman
Location: Canada
| Last time I flew this raptor, all was fine, nice power and head speed.
It was my newly refresh engine, con rod, piston and ring.
On second start up the starting shaft broke up with the top of the pinion gear. “found on inspection”
So, did some research on RR and learn all about the failure of the top of the pinion gear, also that the bearing at that location has a hard life, and that a 3rd bearing mode is available. “Have not bought one yet”.
Also, learn about using lock tight on the starting shaft and the pinion bearing and that one person was using grease instead of lock tight with proven success.
So, I drilled a hole on the side near pinion bearing to allow me to drop some oil.
I also learn about engine alignment “Thank Barracuda” so now the main spur gear is turning very smoothly. So, it should fly better than before..yes
Back to the problem
Did my first flight using a Y.B. pipe, I notice that it was quieter but also seems to have less rev on the engine and from the head, gov working fine.
Flew more flight with that felling that some thing is wrong.
I can do all my tricks, no bogging even if I try but the thing is dragging, it’s not reaching the normal top rev.
So on one longer then normal startup I close the fuel line to the carb. and crank to dry the engine..
To my surprise the engine cranking speed progressively slowing down noticeably.
So with fuel cut off, the engine gets progressively harder to crank and as soon as fuel flow is reestablish, cranking speed goes back up?? Never seen that before.
So, I did listen to the little men on my shoulder and got her back in the shop.
Motor is disassemble
Motor looks fine no noisy bearing.
THE ONLY THING I can see is more wear on the exhaust side of the sleeve extending slightly below the exhaust port and above to the normal travel of the piston.
What do you think??
The engine was not disassemble during the repair of the starting shaft..
With fuel line cut off, I thought that the engine was going to seize up.. That bad |
