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Engine basics => Engine set up tips => Topic started by: Mike Wada on March 01, 2007, 10:56:42 AM
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Aloha,
I was wondering what is the average life span of this motors bushing before excessive fuel leaks out the front end of the bushing? I normally run a rich 2 stroke with GMA 10/22. I have had leaky front end problems lately from an
FP 20 with a relatively new crankcase.
Best regards,
Mike Wada:)
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Aloha,
I was wondering what is the average life span of this motors bushing before excessive fuel leaks out the front end of the bushing? I normally run a rich 2 stroke with GMA 10/22. I have had leaky front end problems lately from an
FP 20 with a relatively new crankcase.
Best regards,
Mike Wada:)
Hi Mike
It is very hard to put a time or number of flights on that,
it depends on your fuel, how rich or lean you run, how heavy your props are, how much sand dirt debris you suck up at launch, There are many factors that will determine how long a plain bushing in any case last.
If you want the engine to last as long as possible use a good quaility fuel, stay away from heavy props, run an air filter over the venturie, try to run the motor slightly richer, or in the FP 20 case make sure your in a wet 2, not a sagging 2. and do not fly in very dirty dusty areas
Randy
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Aloha Randy,
Thanks for the reply and all the support throughtout the years.
Best regards,
Mike Wada:)
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Wise words from Randy.
If your motor is still running well you can always cut an oil collector/return groove at the front of the bushing with a dremel. I use a dentist's burr cadged from my dentist after he's finished attacking my teeth. Measures 0.035" dia.
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Howdy,
Just a short note to let folks know that I tried the technique suggested by Ian and cut an oil groove in the bushing back to the venturi and it really cured the leaky front end. The case was not going to be usable without this modification. It worked well for me. Thanks again Ian.
Best regards,
Mike Wada
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Can you be more specific about the groove? Is it just a straight line parallel with the bore, or do you do something else? I can probably use this information. A picture would be really great to help me understand the method. Thanks.
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Hi. Cut a circumferential groove right round the bushing about 2mm. from the front end. Then cut a straight groove from this circular one back to the venturi opening. This can look messy until you get some practice, but that doesn't stop it working. The excess fuel will be collected in the ring and fed back along the straight groove into the crankshaft. A lot of modern motors already have this as standard. Sorry, not up to pictures yet.
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Good instructions, even I can understand this. Thanks