96 SL 780 Ignition Retard

[bsproul]

A family member has purchased a SL 780. The motor runs great at idle. We have discovered a bad float in the fuel tank and jumpered the sending unit to the controller and got the ski to run up to 4K rpms. However that is it. We have remove the grey wire still does not run wide open. Using the service manual we followed the flow chart and have come to the conclusion the CDI is bad. My quesition is this usually the culprit? It is a very expensive part. We want to be sure before ordering the part.
Also how does each cylinder fire independently? All the coils are wired in series. Where is the trigger for each cylnder?

[ph2ocraft]

First I'd like to say WELCOME to the Green Hulk Forums!!
I think the first thing I'd do is verify the engine itself is in good working order.
How's compression?
How's Crank Index?
When was the last time the carbs were cleaned?
How old is the current fuel?
Will it rev past 4K out of the water?
Maybe put an in-line spark tester and see if the craft is indeed limiting.
Have you tried to trim the spark plug wires back 1/8-1/4 inch and then screw the 5K ohm resistors (Orange spark plug connector) back into the clean wire?
Have you changed the spark plugs?

[bsproul]

Compression is about 125-130 on each cylinder. Have not checked crank index (how do you so this?) Drained fuel and added fresh fuel. All 3 carbs were cleaned. Same RPMs in our out of the water. The plug wires were not the screw in type. They had crimp connectors on them. We recrimped all the connectors. Changed plugs with NGK BR8ES. We are just stumped.

[beerdart]

Compression is about 125-130 on each cylinder. Have not checked crank index (how do you so this?) Drained fuel and added fresh fuel. All 3 carbs were cleaned. Same RPMs in our out of the water. The plug wires were not the screw in type. They had crimp connectors on them. We recrimped all the connectors.Are the crimped ones 5k ohm? Changed plugs with NGK BR8ES. Should be BPR8ES We are just stumped.

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[ph2ocraft]

Crank indexing procedure is in the tech section and if the engine runs poorly or limits at 4K range it's a possible sign of a hydro-lock condition so the crank should be checked to eliminate that as a possibility.
Let us know how it checks out.

[xlint89]

Sorry BD, they dropped the "P" on 780's. BR8ES is correct. Does the MFD work? Is it displaying any problems like low fuel or oil or an overheat message?