beto9
2008-08-01, 05:39 PM
Several visits to the field ago I stopped to buy a coffee and found a penny in the pavement. Picked it up and decided that it was a lucky penny.
I was on my way to the field to test run the OS .91 FX engine in my new Seagull Edge 540.
I never had so many problems with a new engine.
First I had to remove the Bisson Pitts muffler because it was impossible to tune. Either the high or the low were running so so but not both together.
I replaced it with the original OS muffler MINUS the 2.5" extension it comes with.
Luc spent hours tunning it. When it seemed it was running OK it would get our of tune.
It was continously running hot.
Once, by chance, I decided to change the glow plug under the advice of Eric and found the one in the engine was loose, not tight, and probably the reason for the precarious running of the engine.
More time for Luc in the engine.
Again it seemed to run OK but there was no power. It would not make a decent vertical climb. I have the same engine in my Tiger 60 (similar weight with the Edge) and it would get lost itself in the clouds if I let it.
Still running hot.
Today, more fiddling, running it without the cowling because of it running like that... added the 2.5" original extension in the OS muffler to be sure that was not the cause.
Changed the 14x6 prop in case it was a case of overpropping... same running.
After 5 dead sticks in two flying days (two today) trying to test the engine Paul Grenier noticed foaming at the cylinder head. "Albert, it must be loose, tighten the head screws". "Paul, that was the Allen screw I found in the bench, it was a head screw!" Only ONE screw has become loose and fell in the bench. And I had tightned them the previous flying day.
Paul was of the opinion that an engine running very hot may loosen glow plugs and screws very easily.
And it flew OK.
No damage in the 5 deadsticks other than a few nylon bolts in the landing gear and abrasions in my knees because of so much shaking.
Sooooo... was it a lucky penny or a cursed one?
Plane still in one piece!
I was on my way to the field to test run the OS .91 FX engine in my new Seagull Edge 540.
I never had so many problems with a new engine.
First I had to remove the Bisson Pitts muffler because it was impossible to tune. Either the high or the low were running so so but not both together.
I replaced it with the original OS muffler MINUS the 2.5" extension it comes with.
Luc spent hours tunning it. When it seemed it was running OK it would get our of tune.
It was continously running hot.
Once, by chance, I decided to change the glow plug under the advice of Eric and found the one in the engine was loose, not tight, and probably the reason for the precarious running of the engine.
More time for Luc in the engine.
Again it seemed to run OK but there was no power. It would not make a decent vertical climb. I have the same engine in my Tiger 60 (similar weight with the Edge) and it would get lost itself in the clouds if I let it.
Still running hot.
Today, more fiddling, running it without the cowling because of it running like that... added the 2.5" original extension in the OS muffler to be sure that was not the cause.
Changed the 14x6 prop in case it was a case of overpropping... same running.
After 5 dead sticks in two flying days (two today) trying to test the engine Paul Grenier noticed foaming at the cylinder head. "Albert, it must be loose, tighten the head screws". "Paul, that was the Allen screw I found in the bench, it was a head screw!" Only ONE screw has become loose and fell in the bench. And I had tightned them the previous flying day.
Paul was of the opinion that an engine running very hot may loosen glow plugs and screws very easily.
And it flew OK.
No damage in the 5 deadsticks other than a few nylon bolts in the landing gear and abrasions in my knees because of so much shaking.
Sooooo... was it a lucky penny or a cursed one?
Plane still in one piece!