Air screw settings for BF50?

[mathbeak]

Hello from BC, just registered a minute ago... I am wondering what anyone else has found to be optimal air mixture screw settings for BF 50, 2000 model. When the engine was new, it ran poorly at idle (trolling) and a trip to the dealer made no difference. This summer I discovered that the top screw was about 2 turns out, the lower 2 were about 1 turn out, and the motor stumbled along. A call to the dealer resulted in the statement, "settings are 1 turn out, + 1/8. The stumble persisted. <br />Clymer states 2 1/8 out, and at this setting things are smoother, but I can smell the engine running rich while trolling.<br /><br />nb. I synched the carbs very carefully - I made my own liquid balancing manometer. It is very sensitive. <br /><br />Any suggestions on good settings, please?

 

[Skinnywater]

Re: Air screw settings for BF50?

Turn each pilot screw clock wise until it seats lightly. Screw each screw out to it's initial setting, 2-1/8 turns out.<br /><br />Start the engine and allow it to reach operating temperature. Turn the throttle stop screw to the specified idle speed, 950+ or- 50 RPM. <br />(Note: my personal observation is that higher limits means smoother operation, set at 1,000Rpm.)<br /><br />Run engine at idle and turn the #3 carburetor pilot screw in 1/8 turn increments, in or out, until the engine runs at the highest idle speed. If necessary, turn the idle stop screw to obtain the specified idle speed. Perform the same pilot screw adjustment on #2 and #1 carburetors.<br /><br />Lightly snap the throttle several times and let the engine return to idle. Turn the throttle stop screw to obtain the specified idle.<br /><br />Recheck and do this all in conjunction with carburetor syncronization.<br /><br />Let us know how it turns out please.

 

[mathbeak]

Re: Air screw settings for BF50?

Thank you very much - I will try to get back to this next weekend - fishing is still pretty good. Only my day job gets in the way!!

 

[mathbeak]

Re: Air screw settings for BF50?

I synched the carbs to within an inch of their lives - I found that even rotating the plastic/metal linkage between them affected the settings to a degree. I made an oil-filled "manometer" tool to balance the vacuum, and bought fittings to thread into the runners. Works like a charm, and is very sensitive. The dealer had a setup of gauges that is crude by comparison.