3.7 Mercruiser starting problem

I have 1987 Baja with a 3.7 Mercruiser engine- never had an inboard engine. I bought at a good deal but needed engine work- 2 cylinders had no compression. All 4 cylinder walls and pistons were in great shape but it had a blown head gasket. A new head gasket (along with the head being cleaned, shaved and checked for proper working order) and compression was fixed. I put it all back together and a new marine battery but the engine will not make a complete revolution without stalling- not even close to starting. I took the spark plugs out and the engine will turn over. I guess the cylinder pressure can't escape and removal of the plugs allowed pressure to get out. Now for the big questions, why will this engine not turn over? Is there a simple way to check the timing without taking off the timing cover? If the timing is off, would it act in this manner? Any other things I should check before checking the timing? I have been reading this forum and there seems to be alot of boat savvy users here. I have learned alot about this engine on this forum already and hate the thoughts of replacing the timing chain due to the chance of having to pull the engine out of the boat if I mess up the oil pan gasket, but if thats what I have to do then I will. Thanks for any help with this issue.

Re: 3.7 Mercruiser starting problem

Ayuh,... Sounds like a Bad starter, or Bad starter Wiring...

Re: 3.7 Mercruiser starting problem

copper top;3342372 engine will not make a complete revolution without stalling- not even close to starting. I took the spark plugs out and the engine will turn over. I guess the cylinder pressure can't escape and removal of the plugs allowed pressure to get out. Now for the big questions said:

Agree with Bond-o, with the plugs out should spin right over. 470 starters will often have a broken or bent armature over time that will rub against the field coils and turn very slowly or not at all. You can replace it with a 2-2591-DR-2 permanent magnet gear reduction starter, smaller and easier to install. For the timing, find TDC on the compression stroke of #1 cylinder, the timing mark on the harmonic balancer should line up with the 0 timing mark on the timing chain cover, and when you take the distributor cap off the rotor should be pointed at the #1 plug wire (should be close enough to start). If you think it is too far advanced, rotate the distributor clockwise (mark the original position first). Good luck.

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Re: 3.7 Mercruiser starting problem

Thank you both very much for the advice. I will for sure check the starter first.