We get letters, #11:

"Hello, I have a 1991 Hallett Vector with a carbed 454 and Bravo 1. The hour meter has not worked since I've owned the boat. I have absolutely no idea how many hours it has on it. It doesn't seem to use a lot of oil, but it definitely feels tired. I had a compression check done and all 8 were a little low, but within a few pounds of each other. I don't remember what the compression was. I've done all the recommended maintenance on the engine and drive. The drive was opened up and inspected about 2 years ago. Since then I've put maybe 50hrs on the boat.

I don't have a lot of money to spend. I've heard a lot of different advice. Do a top end, heads, valves, etc. Also heard do a complete rebuild. Also was told it might be cheaper to buy a used low hour replacement engine.

What do you think I should do?"

I enlisted the help of a member and friend who I thought was much more qualified to respond, here is his response:

A leak down test will better determine what, if anything, is wrong with the engine, whether rings or valves are not sealing. Without knowing what the compression test numbers were, or even how that test was run, it doesn't give us much to go on.

When was the last time the engine was tuned? What exactly does "it feels tired" mean, top end, out of the hole, midrange?

I would also ask someone who knows a bit to visually look at the engine and try and determine if it has aftermarket gaskets, or may still be all original (22 years old?). Depending on usage, and previous owners care of the engine, possibly it is time to do it. Obviously money plays into it, but it's difficult to recommend just doing the heads if the rings are worn out,, and also obviously have no idea of the condition of the bearings without getting into the bottom end. It's a snowball effect thing at that point, do you go ahead and but in a better cam, heads and manifold to make more power?

Back to the first paragraph, if there is a question about how tired it is, a leak down will give an indication if it's important to spend money on it now or if it's reasonable to continue to just run it as is, assuming that the engine is already properly tuned and timed right, all 8 spark plugs firing, etc.

Barry aka Obnoxious001

Barry thank you for taking the time to help me with this one, it is appreciated.

I hope this answers his question.

HB