UtahBoating
Petty Officer 2nd Class
- Joined
- Dec 8, 2008
- Messages
- 102
I am looking for some help with my power problems. I recently purchased this boat 17' Bayliner Capri with 1989 Force 85HP. The boat starts easily and runs fine. But it is slow and flat on the top end. I posted about prop pitch a week ago thinking that was my issue. The boat currently has a 15 pitch prop on it and my top speed verified by GPS is only 22mph. This is at 5k elevation if that makes any difference. I ordered a 17 pitch prop but I don't want to use it until I am satisfied the engine is good.
Other posts I have read says they get 35-38mph with this size boat and motor. I have verified all 3 cylinders are getting spark. I bought a cheap HF compression test kit and am only getting 92psi on all 3 cylinders, hot or cold, and WOT or neutral. I was convinced maybe the HF tester is junk so I borrowed another cheap one from Oreilly's and am getting slightly above 100psi on all 3 cylinders. I know both of these are cheap chinese made testers but I can't imagine 2 reading almost the same can both be that far off. I also can't imagine if I stick the new prop on I am going to get 10mph more.
Unfortunately I don't have a tachometer on this boat so I can only go off sound. Should I pull the heads and replace the gasket? I was going to pull the carbs and clean/rebuild but if the compression is no good I don't want to waste time on that. The only thing that is throwing me is all 3 cylinders are within 1-2psi of each other. I would think 1 would be significantly different than the others if the rings were bad?
While the boat is off I have put it at WOT throttle and verified the butterfly's are opening in the carbs.
Looking for input please. My choices are to inspect the cylinders and put new rings in (I have read this is not too difficult) or I can sell the boat at a loss and buy a different boat.
Thanks in advance!
Other posts I have read says they get 35-38mph with this size boat and motor. I have verified all 3 cylinders are getting spark. I bought a cheap HF compression test kit and am only getting 92psi on all 3 cylinders, hot or cold, and WOT or neutral. I was convinced maybe the HF tester is junk so I borrowed another cheap one from Oreilly's and am getting slightly above 100psi on all 3 cylinders. I know both of these are cheap chinese made testers but I can't imagine 2 reading almost the same can both be that far off. I also can't imagine if I stick the new prop on I am going to get 10mph more.
Unfortunately I don't have a tachometer on this boat so I can only go off sound. Should I pull the heads and replace the gasket? I was going to pull the carbs and clean/rebuild but if the compression is no good I don't want to waste time on that. The only thing that is throwing me is all 3 cylinders are within 1-2psi of each other. I would think 1 would be significantly different than the others if the rings were bad?
While the boat is off I have put it at WOT throttle and verified the butterfly's are opening in the carbs.
Looking for input please. My choices are to inspect the cylinders and put new rings in (I have read this is not too difficult) or I can sell the boat at a loss and buy a different boat.
Thanks in advance!
Last edited: