Difficulty starting after multiple recent repairs, but runs well after starting

[birdpiper]

We have a 1999 FourWinns 190 Horizon, 4.3GL PWTR VP engine. We had several repairs done to the engine in the past two years. The most extensive repair was when the engine was removed, rebuilt, and re-installed due to a head gasket failure two seasons ago. The engine performed ok for a few months after the repair, but then started having problems starting. Overall it seems like the starter is encountering some resistance when it engages. It will just barley start after a few attempts. Once it starts it runs just fine.

The mechanic that performed the engine overhaul has since also performed the following additional repairs, but the problem continues:
1 ? Replaced both manifolds and risers
2 ? Replaced the starter twice
3 ? Replaced the flywheel
4 - Replaced all of the spark plugs
We performed a diagnostic on the electrical system and ruled out any electrical system issues.

Last fall we were able to get it started after a few attempts in order to winterize. We will be getting it ready for the 2017 season in a few months.

Any ideas on what we should look at next? Would an engine compression test be worthwhile?

 

[Lawnpro979]

I had a starter replaced one year after purchase of my boat Volvo penta 4.3 the starter was burned all the way up.....
The next year I had to have the starter replaced. It seems it was dragging, the only thing I could think of was that it got flooded once. It built up like you stated resistance..my electric system was great. New battery. Mine was a pita to get too. Was shocked it only lasted a year.

 

[alldodge]

Have you checked closely at your battery cable ends, both ends and both pos and neg?
What size cables are they?

 

[jimmbo]

I agree it sounds like a cable/connection/corrosion issue

 

[birdpiper]

Thanks for the feedback. We are not completely ruling out an electrical issue, but we:
1) Went through the "troubleshooting a Volvo starting system using a 12 volt test light" (attached) guidance and all tests passed
2) I inspected, cleaned, and applied di-electric grease to all electrical connections/cables when the starters were replaced. Didn't get to the main engine block ground connection since it was hard to reach, but a visual inspection (reaching back and taking pics with my phone) didn't show any corrosion.
3) Disconnected the boat battery and used a new car battery (temporarily) to start... same result

 

[alldodge]

Test lights are great for quick checks, but they come on even if voltage is a bit low. You need a voltmeter and connect it to the starter post, and keep it there when the key is turn to start. Voltage should stay above 11V.

Your ground on the block could look good, but be corroded under the insulation, not saying this is the issue, only a possibility