Two years ago I experienced a drop in rpm's to about 4200-4300. I took it to a marina and asked them to check out the engine. The said that it needed a complete rebuild which they could do over the winter. Well I never had them do the rebuild, the boat has just sat in my warehouse for two years. Recently I've been trying to decide whether to rebuild it or repower not knowing if I was going to keep the boat or not. I haven't had great success with this marina in the workmanship or trust arenas. I decided that I would play around with it a bit this week. Well after two years of sitting it fired right up, sounds great, and runs (idles) smooth. This morning I did a compression test and here are the results;
The proceedure;
1) I warmed the engine up (about 150 degrees)
2) Removed flame arrestor
3) removed all plugs
4) throttle wide open
5) checked in the following order;
The engine currently has 525 hours on it. I imagine I still have the lower than expected rpm issue that I had a couple years ago. Based on these numbers does anybody have any opinions of what I should do? If your in the michigan area please forward names and numbers of shops that you recomend do the work.
I agree with formula. Keep running it till it really goes south. Then either get yourself a new/rebulit shortblock & have the heads redone. Or spend a few bucks more and buy a new/rebuilt engine complete.
Gary
You could also squirt some oil in the low reading hole and retake the compression reading. If the compression comes up, need rings. If there is little change, valve job. I'm betting on valve job.
Does not sound too bad for the hours and all. But, after 500+ hours your valves and springs are done. I'm sure if you did a leak-down the top end will be the culprit.
Tired valve springs make a very effective rev-limiter.
Hi. I'm in Livonia. I can do your rebuild for probably 1/2 the marina price. Let me know if you are interested. I just did a 5.7L which you can see+hear run to verify my work.
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