Help! Can't get my 96 Challenger 787 to rev past 5000!!

[mwestmstrum]

I had a few minutes to mess with the boat tonight, so I thought I would try to get back to basics. I wanted to confirm if it was a fuel delivery issue, or electrical.
I fired in some new plugs, and the motor was very difficult to start. Choke didn't help, and it took forever to finally get it running. I tried quick start to help the starting problem, and it didn't kick at all with a good shot of quick start. I did eventually get the motor running, and once again it wouldn't rev past 5500. I had my wife drive and I shot a bit of quick start in the flame arrester and the revs didn't change. It still idles well and transitions to mid range decently.
I brought the boat home and pulled the plugs and they were very similar to the last plug check. The pto plug is still very lean, and both plugs are very dry.

Is it a safe assumption that the problem is electrical, and more accurately in the PTO cylinder?? We covered this a few days ago, but I think that this confirms the direction to head when I get home. We will have better resources to check the possible trouble items discussed before.

Thanks again for all of the input with this. It has been an interesting problem.

Mark

 

[ORION '95 Speedster]

Hi, your compression looks good. 125psi is fine, and you do not need to repair or replace the top end. As long as the numbers are close to each other, no rebuild is needed. If any of the cylinders are under 100psi, or there is a huge difference in the numbers, mechanical repair would be needed. If you contact a dealer, they will tell you that you need to replace the top end, regardless of what the compression readings are (that's how they make money).