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Discussion Starter · #1 ·
I am trying to diagnose a 95 panther 440 (f/c) that doesn't run right. The engine starts on the 1st or 2nd pull when cold, then runs a mile or so until it bogs and dies, then won't restart until it is cold. I cleaned the carb, which as pretty gunked up, and this helped with the fouling on the plugs, but no difference in how it ran.
I suspect a new top end is needed. Compression is 90psi in both cylinders. Tested with the engine cold and full throttle. What is a good reading on this engine, I guess it should be about 120? Sled has 8k miles.
 

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You are correct. The sled may run with 90 PSI but the proper compression for this engine should be 120 plus.

I have rebuilt\modified 3 fan 440's. Great motor, almost bullet proof.

Also check you jetting. You may be too rich. I found a main of 280 worked perfectly.

Ben
 

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Discussion Starter · #3 ·
thanks. i a m awaiting new pistons and rings, hopefully they will be here in a day or two. Guess I should have mentioned the sled has 8k mile on it, so I guess its rebuild time. Hopefully it will be quick and painless.
I checked the jet and it was right size for the altitude\temp I am running at (8-10K).
 

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Doing the top end on the 440 is a breeze. Its so simple there is really no tricks I can pass on to you.

If you have time I would suggest you mate the exhaust ports and header to the size of the exhaust gasket. Its a bit of work (the exhaust port gets ground out as does the inside of the header) but you will find this will really help the little 440 breath.

You can also take 1 -2 mm off of the intake side of the piston skirt for each piston. This will open your intake port up a little sooner so you can get a larger charge.

You can take more than 1 mm but with 8 K on your bore you may end up with piston slap under acceleration (and then you would not be happy with me) so be careful here.

Other than that, have fun.

Ben
 
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