'98 75hp Merc problems???

[ewirz]

This is a puzzeler. Motor is on a '99 Tourney Pro 175. After it warms up, REALLY struggling to get on plane, especially when loaded. It will only get up to around 5k rpm (its not the prop, have run with same prop at 5500). Have had the compression, stator, triggers, and coils tested and all are ok. Put a new fuel line/bulb on and couldn't seem to find any air leaks. Any thoughts on what the problem may be? Thanks for the help,

ERW

[Rost]

Not sure, but let me know when you find out. I am interested because I have the same motor.

[iffy]

It could be that something is wrong in the lower unit and making the motor work that much harder. A bearing could be seizing. You would need to take the unit off to check that out. Otherwise, check your fuel pump diaphragms. They don't cost a lot. Replacing them is a pretty easy and quick job.

[ewirz]

Well, here's the scoop....

It was a bad CDM. The "newer" merc's have these. Its a combination switch box/coil (if I understand it right). Easy fix, just bolt on the new one and plug it in. Part was around $80.