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onesubdrvr
04-02-2005, 06:50 PM
OK,............ Here we go AGAIN!

New engine, usually starts right away, then dies (like it's not getting enough fuel), so I adjust the idle, sometimes starts right away, sometimes acts like it needs to get fuel back to the carb. When it starts, usually end up at about 1200rpm idle, after it runs for say 5 minutes, I can back the idle back down and it seems OK. I guess the big thing is, I can't seem to get the idle adjusted correctly, maybe a mixture problem?

Edelbrock performer 600cfm Marine carb, performer manifold,....

Any suggestions?

Will anybody who can tweak a carb good be at the AngelAID run in a few weeks?

Wayne

smokediver
04-03-2005, 10:03 AM
Do you have an electric choke ? Sounds to me like the choke needs adjusting . It might be needing air , not fuel. At a cold start , check the position if the choke .... that is a pretty easy carb to mess around with .

MOP
04-03-2005, 11:11 AM
If you are sure the floats are set correctly and reasonably sure the jetting is correct for the application, the next step that I have learned that helps to get things right, back off idle screw completely. Now check the carb butterfly plates to see if they are seated correctly, this is done by taking a screw driver and tapping on the high side of the closed plates on top and again the high side from the bottom. They should sound solid in the bores, if any of your plates is not seated properly you will not get a good adjustment. If find one not seated it will require a little work, the carb needs to be removed to do work. Some plates can be corrected by breaking the screws loose just a tiny bit (don not remove they are knurled on the screw end so they can not vibrate out) if you can carefully fiddle with the plate and get it to seat tighten the screw. A tiny dab of "red Loc Tite has to be applied to the thread end of the screw and left to dry. You need a vacuum gauge and the adjustment chart specific to the carb, follow the manufacturers specs to a T. All carbs are basically the same but also have different quirks in their set up, air fuel setting mixture should not vary more then about ½ turn from the carbs spec sheet. If you are way out of range with the idle screws you are trying to correct another problem in the carb or possibly an air leak in the intake tract. Good carb adjustments should always start on the bench, even a brand new carb should at the very least have a float adjustment check, and felt for any binding moving the throttle through its range. What makes you think the postman did not drop it!

Phil

onesubdrvr
04-03-2005, 11:16 AM
Well,

Took care of the ignition stuff and got the boat out today, I think I have a combination of problems,

1) Carb adjustments
2) Timing

On timing, where should I be, the book says 8* BTDC, but I'm wondering with rebuilding the engine if I should advance it some? What about plug gap? I stayed with OE specs there too.

Please Help,
Getting Frustrated
Wayne

MOP
04-03-2005, 11:34 AM
Wayne check the response Jamie posted about timing, true it is about Merc but basic timing setup is the the same for all engines. Top timing is the most important, page #3 has some very good reading about setting initial timing, the whole thing is worth reading. Ans another thank you to Jamie!

http://www.donzi.net/forums/showthread.php?t=38371

Phil