Justin,
I've been saying this on the list a bunch lately, here is a link with some detail on the tune up procedure I use...
http://www.allpar.com/fix/carb-tuning.htmlI like the vacuum guage procedure because you can tune your engine "BY THE NUMBERS" no room for subjectivity...
the link will back me up on this, get it running and warm, check your timing, get the idle speed (on the port side) in the ball park, adjust your port mixture screw in till it stumbles then out untill you peak the vacuum. adjust your starboard mixture screw in till it stumbles then out to peak vacuum...repeat...timing, idle speed, mixture (peak vacuum) untill you can get no further improvement.....BY THE NUMBERS you are looking for timing 5 degrees BTC (at idle), idle =550 RPM, maximum vacuum possible with the timing and RPM dead on (vacuum reading will vary by engine but guessing you should be in the 20 PSI territory)
The only difference you may have from this car tune up proceedure is that I don't believe you have a vacuum advance on your distributor (a little cone with a vacuum hose that goes to a vacuum port on the carb)...So you will be able to ignore the golf tee part,
SIDE NOTE: When you get your manual it will talk about the mechanical advance but basically the advance curve is controlled by weights and springs inside the distributor and are pretty light compared to "normal" automotive applications. Boaters aren't starting and stopping or changing gears so if you throw the throttle down we want to get the timing advance in pretty quickly to get us up to max power to tow that skier and once we get up to speed we stay there for a while...
hope this is helpful.
Cheers,
B.C.
Received on Friday, 18 September 2009