1989 Evinrude 110 hp just rebuilt. Low compression, wont idle below 1500 rpm

I have a 1989 evinrude V4 110 hp. When i got it the pistons were fried and also blown head gasket. I honed out the cylinders put in new piston and rings, polished the crank but no new seals for crank. I also cleaned the carburators twice but didnt put new kits in yet. Im still having a problem with low compression on all 4 cylinders 1-60psi 2-55 3-60 4-60. What else can cause low compression? Primer solenoid is ok but i have to use Ether while feathering the throttle to start it and when its running at about 1500-2000 rpms it runs ok, but anything less than that it dies. timings good at about 24 degrees BTDC. I really didnt look closely at the leave valves but i can if its suggested.. I normally work on cars but this is my first marine motor. I have a manual but it doesnt answer all of my questions. . Any pointers or advice would be much appreciated.. thanks in advanced.

Re: 1989 Evinrude 110 hp just rebuilt. Low compression, wont idle below 1500 rpm

I had same compression readings on mine and went to all sorts of trouble finding out why. Come to find out, the automotive compression tester I borrowed from auto zone didn't measure properly. I went to my local Johnson dealer and asked very nicely to use his (had boat on trailer w/ me) and it read 110-115psi.
Just saying

Re: 1989 Evinrude 110 hp just rebuilt. Low compression, wont idle below 1500 rpm

gruppthepupp said:

and also blown head gasket.

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I take it you replaced this too with the correct replacement part and also torqued the head down correctly?

bad compression will make it hard to idle.

Re: 1989 Evinrude 110 hp just rebuilt. Low compression, wont idle below 1500 rpm

It's no wonder the engine won't run with those compression figures. I would think you should be seeing 95 lbs compression. On the 2 strokes low combustion compression means that you also have low crankcase compression-low crankcase compression means it's hard to draw fuel/air into the carbs. It sounds like the engine may have been severely oveheated. Did you check the clearances between the pistons and the cyl walls? Also, did you check for taper, out of round cylinders? Did you reassemble the crankcase halves with the special gel-seal? A 1990 V4 engine should be timed at 28 degrees-max timing at WOT-set while the engine is at 5000 rpm's. I would think your 89 would be about the same timing. Idle timing should be set around 4 degrees for starters, then reset when the boat is floating in the water.

Re: 1989 Evinrude 110 hp just rebuilt. Low compression, wont idle below 1500 rpm

I used a compression tester from autozone as well. I believe the engine was severly overheated. I used the right replacement gaskets and checked them against the old ones just to be sure. I unfortunatly didn't use the gel seal for the crankcase halfs I used a high temp copper gasket sealer as was suggested. As i was tearing it apart i did notice the pistons were pretty loose inside the cylinders but i figured that was because the rings were fried. I didn't check the cylinders for out of roundness or taper. I think ill try another compression tester before tearing it back apart and doing it again. lol. Thanks guys for the advice.

Re: 1989 Evinrude 110 hp just rebuilt. Low compression, wont idle below 1500 rpm

gruppthepupp said:

I used a compression tester from autozone as well. I believe the engine was severly overheated. I used the right replacement gaskets and checked them against the old ones just to be sure. I unfortunatly didn't use the gel seal for the crankcase halfs I used a high temp copper gasket sealer as was suggested. As i was tearing it apart i did notice the pistons were pretty loose inside the cylinders but i figured that was because the rings were fried. I didn't check the cylinders for out of roundness or taper. I think ill try another compression tester before tearing it back apart and doing it again. lol. Thanks guys for the advice.

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Try this simple test... Wearing a pair of work gloves, turn the flywheel in a CLOCKWISE direction, by hand. Does it have resistance, kick back when you release? or Does it turn easily through the compression cycle? If it turns easily without kick back, then you have a compression problem.

Re: 1989 Evinrude 110 hp just rebuilt. Low compression, wont idle below 1500 rpm

I have a evinrude 110, 1986, and the compression is hitting 58 on two and 60 on two. The book says they should be 100, I did the whole turn the fly wheel clockwise, have resistance and spin back. I had a 13.5 15 pitch stainless prop on it, I just bought a 13.5 17 pitch Aluminum prop so we can pull water skiers, the other problem we have besides the compression, is the boat won't plane out with the new prop, planed out just great with the old prop, going to the lake tomorrow with the old prop back on to see if it planes out again. I was told the 17 pitch Aluminum prop was more like a 13 stainless would be and should have no problem getting up out of the water. The motor runs great, has compression (maybe not as much as it should) and fuel/oil seem fine, new spark plugs and vacuum line. Could it be the prop that is keeping it from planing? Would appreciate any help!

Re: 1989 Evinrude 110 hp just rebuilt. Low compression, wont idle below 1500 rpm

mandbh64 said:

I have a evinrude 110, 1986, and the compression is hitting 58 on two and 60 on two. The book says they should be 100, I did the whole turn the fly wheel clockwise, have resistance and spin back. I had a 13.5 15 pitch stainless prop on it, I just bought a 13.5 17 pitch Aluminum prop so we can pull water skiers, the other problem we have besides the compression, is the boat won't plane out with the new prop, planed out just great with the old prop, going to the lake tomorrow with the old prop back on to see if it planes out again. I was told the 17 pitch Aluminum prop was more like a 13 stainless would be and should have no problem getting up out of the water. The motor runs great, has compression (maybe not as much as it should) and fuel/oil seem fine, new spark plugs and vacuum line. Could it be the prop that is keeping it from planing? Would appreciate any help!

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Ok, so put the old stainless prop on and it planed, still running slow coming up but planes great