750 SL Carb Settings

[lakenut]

Clymer manual calls for the following carburetor high speed setting for 94 SL 750

Magneto end Cab - 1 1/4 turns open
Center - 3/8 turn open
Rear - 7/8 turn open

Is this correct?? Why are they not the same setting for each??

Magneto piston burned a hole. Understand it ran too lean. Should I go for 1 1/4 setting above?

Pix attached

[johnsonmtz]

A hole in the MAG cylinder is a classic problem on the 750's due to the OEM single outlet fuel pump. Take a look at the schematics here: http://www.greenhulk.net/forums/showthread.php?t=15433

This shows you how to replumb your carbs for the triple outlet fuel pump and avoid this problem.

KJ

[xlint89]

Welcome to the Hulk Lakenut.

Yes, those settings are correct.

Each cyl is tuned diferently because a few reasons.

The MAG cyl tends to run hotter than the other 2 because of the stator creating heat in front of it. The MAG also has more surface area than the other 2, which usually requires more fuel.

The CEN does the least work, which means less load. So in turn requires less fuel.

So, because of heat differences, and load differences, each cyl requires different amounts of fuel to run most efficiently.

Weak fuel pumps CAN lead to a holed piston, but it doesn't mean THAT'S what caused it. There are many things that can contribute to the lean condition. (lean meaning, inadequate amount of gas that makes a piston run hot and erode the aluminum)

Here's a list of some common causes.
http://www.greenhulk.net/forums/showthread.php?t=82682

[lakenut]

Thanks xlint89 and johnsonmtz.

I have two line fuel pump that has been in place for years. Do not think that is the problem.

I had a Polaris shop adjust the carb's for me last year. I am guessing he just ran that carb too lean.

I will count the turns going in to see how far off they are from 1 7/8. That should give me an indication on how the shop adjusted the carb.

Thanks