SharpProp

I'm trying to break my .061 in and its only getting up to around 11,000 rpm and then it dies from what i'm guessing is overheating. I believe i'm running it rich enough i'm making a hell of a mess with the oil thats coming out of the muffler and I believe its coming out of the front of the crank case a little bit. Just behind the propellar. Its' hard to tell tho. I really want this engine to run well but i'm starting to think that it's not going to . The propellar I'm using is a 6x3. Any advice on if this sounds normal and I should just keep breaking it in Until it peaks out.....or does it sound like the engine is screwed.

SharpProp

oh by the way.....it runs for a bout 2/3 of the tank before dying. then the head is super hot and it feels like there isn't much compression. That's why I'm wondering if this engine is screwed.

on pipe

There's a sticky at the top of the 1/2A column for Norvel engines. It includes instruction for break-in, etc. ABC type engines should be broke in just slightly rich of peak RPM to keep the cylinder temperature correct, (hot enough for expansion) so that the "pinch" at TDC is not lost. Ross

longdan

Some norvels have a very tight fit between the crankshaft and crankcase, which requires the shaft to be lapped. There are instructions somewhere - maybe in the sticky at the top, on how to diagnose and fix this.

flyinrog

My Feedback: (1)

The ap wasp .061 is a copy of the norvel and it needs several oz of fuel through it before it begins to loosen up...sounds like your running it too rich with the mess its making....run a couple more tanks and then try a smaller prop 5 x 3 maybe, they are usually very good engines once broken in...Rog

gcb

What type of fuel are you using? Make sure it has sufficient lube. I would suggest 18% minimum. I like 20%-22% half castor. Some car fuels run on much less lube (~9%?).

George

combatpigg

My Feedback: (3)

Make sure that you have a good compression seal with the head. Not a bad idea to replace the head. Once you are satisfied that the head is not leaking, bring the piston up to TDC slowly and note how long the cylinder stays pumped up with air. It should hold compression for at least 5 seconds, if not much longer. If not, the piston and or liner could be gouged enough to where there is no hope. You can disassemble the engine and inspect the parts under magnification to see all kinds of ugly stuff going on if the engine is a dud.
I have seen lots of gouging of the piston and liner in line with the wrist pin bore.
You should expect to see at least 15,000 with a 6x3 prop if the engine is any good at all.
If it seems down on compression, don't waste time beating a dead horse until you find out why the compression is low.

SharpProp

ok Last night I went to a club meeting and one of the "old guys" told me that its probably lean. He told me to richen it up and be patient with it. So I went home and richened it about half a turn and it sounded alot better. I didn't get a chance to put the tac on it due to it was dark outside and my florescent lights mess with the reading. anyone know of a good method to get a good reading when the sun is down? anyway that higher pitch made me feel alot better and I'll continue to run a few tanks through it and see how she does. I noticed some bubbline around the glow plug. I tightened while it was hot and I hope tonight I will not see them anymore. My carb is rocking when I transition the throttle. I need to find a good fix for that. I think I read somewhere that fuel tubing can do that. Maybe if i'm lucky I'll finally get this bird up in the air this weekend.

DeviousDave

a flashlight behind the prop will get a reading in the dark.

Larry Driskill

Sharp, If you still have a head leak (put some light oil on the plug and the clamp that holds it and turn the prop thru slowly looking for bubbles) then try this.

Find a very flat surface (a sheet of glass borrowed from the medicine cabinet works well) and buy a sheet of 600 wet/Dry sand paper. Remove the plug and and the head shims.

Put the sandpaper on your flat surface with a few drops of lightweight oil. Face the bottom of the plug with a soft figure 8 motion for a couple of minutes. Use a fingertip to do the same to both sides of the shims. Examine both the shims and plug to see if the surfaces of both appear to have been cleaned up. Face a bit more, if needed.

Clean any residue off all the parts and reassemble.

Quitely return the loaned glass to its cubby.