Pro70 Engine Help
10-12-2009, 12:06 PM
#1
Pro70 Engine Help *SOLVED WITH PICS*
Hi All,
I have an EK4 with the Pro70 engine (ringed) that I just replaced the piston in. This is the 2nd time I have had it out since the piston replacement. It fired right up and I have it set up very rich for break in. I ran it around for 5 minutes or so (ran very well, popped wheelies and all) and then it just stopped. I could not restart it. I pulled the head and all looks well. The piston seems tight and I seem to have good compression. When spinning the engine it will just not catch. Occasionally it will backfire through the carb but never start. I am at my wits end as this was running so well. I have replaced the glow plug several times and am using a new battery and confirmed the glow plug lights up.
Any ideas?
********
Well I tore down the engine and this is what I found. The connecting rod lost its brass bushing which is in pieces in the engine. You can see the pieces in the 2nd pic on the wedge. When I put this back together I wasn't sure how to get the piston on the crank-shaft and basically forced it. I guess I damaged it in the process. I don't think there is any damage accept the rod. I'll see if I can get another rod but this engine is obsolete so I am not sure I will be able to get one. Maybe I'll call thunder tiger and see if they can help. Another day in paradise.
I have an EK4 with the Pro70 engine (ringed) that I just replaced the piston in. This is the 2nd time I have had it out since the piston replacement. It fired right up and I have it set up very rich for break in. I ran it around for 5 minutes or so (ran very well, popped wheelies and all) and then it just stopped. I could not restart it. I pulled the head and all looks well. The piston seems tight and I seem to have good compression. When spinning the engine it will just not catch. Occasionally it will backfire through the carb but never start. I am at my wits end as this was running so well. I have replaced the glow plug several times and am using a new battery and confirmed the glow plug lights up.
Any ideas?
********
Well I tore down the engine and this is what I found. The connecting rod lost its brass bushing which is in pieces in the engine. You can see the pieces in the 2nd pic on the wedge. When I put this back together I wasn't sure how to get the piston on the crank-shaft and basically forced it. I guess I damaged it in the process. I don't think there is any damage accept the rod. I'll see if I can get another rod but this engine is obsolete so I am not sure I will be able to get one. Maybe I'll call thunder tiger and see if they can help. Another day in paradise.
Last edited by slipgate; 10-13-2009 at 02:38 PM.
10-12-2009, 02:25 PM
#2
Tech Initiate
That's A Super Tigre built engine correct? It's been a long while since I ran a ringed glow engine (Airplanes) But I used to run a ringed Super Tigre .51, the only time it would 'backfire' through the carb is when it was filthy rich or flooded. It doesn't sound like that would be your problem, it could be a start.
10-12-2009, 03:03 PM
#3
That's A Super Tigre built engine correct? It's been a long while since I ran a ringed glow engine (Airplanes) But I used to run a ringed Super Tigre .51, the only time it would 'backfire' through the carb is when it was filthy rich or flooded. It doesn't sound like that would be your problem, it could be a start.
BTW: Yes Thunder Tiger EK4 with Pro70 ringed helicopter engine.
10-12-2009, 03:07 PM
#4
Tech Initiate
Usually a pretty quick way to un-flood an engine to the point where it will start is to take the fuel line off the carb so no more fuel enters, take out the plug, open the throttle all the way, and turn the truck on it's side or upside down and turn the engine over until no more fuel comes out the plug hole. Then re-install plug, reconnect fuel line, carefully re prime and fire it up
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