K&B 7.5

[joey padgett]

I have a flow meter
What should I set the carb to break the engine in

 

[Wasted wages]

Sloppy rich, 2-3 tanks buzzing around the pond trailing blue smoke...
Then start leaning on it a little bit at a time..

If it starts pulling plugs, richen it back up...
Then flow it... carb wide open.
You will then have your number...

 

[Wasted wages]

Let me explain a little further...
There no " setting " for any particular engine and needle valve setup. Always flow thru the needle.
Even if you use a third channel setup.

Flow meters also vary from unit to unit.
It also depends on what type of flow meter you use.
Mine is old school propane... what I would get on my meter would probably be different from anyone else's... also air temp, density, the boat setup all play into it.

Once you get the motor running happy and you are satisfied with the performance, that's when you flow it. That will be your baseline number.
Keep notes, air temp etc. That way you will have a starting point to get back to if things start to go wrong.

If you travel to other sites to race, your setting may change some due to elevation changes etc.
But at least you will know you have a starting point to work from. It's all about keeping notes...

 

[joey padgett]

Thank you Frank

 

[Kez]

Running on the rich side is definitely good. But if the K&B has very tight fit at TDC, it should not be run too rich. The engine will not get up to proper running temperature if it is too rich and the piston/sleeve will remain tight. Although I have not experienced it myself, I heard it can cause the conrod to fail because the tight fit put a lot of stress on the rod.

 

[joey padgett]

Thank you Kez

 

[dwilfong]

Well to set the needle you fire it up and let it warm a little. then pull the trigger and see how quick the eng clears out and revs up.
Turn it till it dose not clear out. then turn it back till it just doses rev up.
Then it is set rich.
If you turn it in till it only hesitates very little it is lean.
You want it to take a second or 2 to clear out on the bench.
This will get you very close to tuning it correct.

 

[joey padgett]

Thank you David