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KB7.5 Outboard

Old 10-31-2005, 09:30 AM
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Default KB7.5 Outboard

Does anyone know how to determine when you have enough compression, we can't seem to get the enging running and are trying to eliminate things as we go...

As always Thanks for your opinions!!!!
Old 10-31-2005, 01:55 PM
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Default RE: KB7.5 Outboard

I don't know what you do or do not know about K&B's so don't feel insulted. first, are you spinning the motor the proper way? This means are your starter leads reversed? You'd be surprised at how many first-time K&B OB owners don't know this as they do run backwards.
Fuel pressure line hooked up? Carb setting should be at around 3-1/2 turns out on the high-end needle, maybe a little richer in this colder weather. Leave the low-speed needle alone.
To check the compression is mostly by feel unless you have a pressure guage to determine it which most of us don't. If it feels tight at the TDC, it's great. If you can turn the motor to the TDC and if itr feels like it's leaking down past the piston then it's time for a rebuild. K&B's are tougher as they really don't have a lot to begin with. Most will run half-way decent until they're about shot.
Where are you at in Michigan? You can see where I'm at.

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