West32
Active Member
- May 24, 2017
- 215
- Boat Info
- 1999 Sea Ray 370 EC Hardtop
Raymarine Axiom Pro system,AutoPilot,Radar,VHF,XM,Mercury Engine Gateway
- Engines
- Twin Mercruiser 8.1 Horizons with ZF Hurth Transmissions
I purchased a 1999 Sea Ray 370 EC with 3500 hours on it in July of 2017 knowing the port motor had issues. When I finished the 2017 season, I pulled the motor and brought it to a very reputable motor builder. He went through the entire motor and found the Cam was bad (Wiped Out). The bottom end was perfect, so he honed the cylinders, put new rings on the pistons,New bearing, Cam, new oil pump and did a valve job... I put it back in the boat and it ran great. This year I noticed performance starting to go down throughout the year. I did a compression check and found 125 to 130 across all 8 cylinders. I pulled the motor and brought it to him. Everything inside looked great except for the Intake Valves. All 8 intake valve seats showed a gap on 25% of the seat next to the Exhaust valve. There were NO signs of heat build up anywhere. Nothing was discolored. Nothing smelled when he pulled it apart.
Has anyone ever heard of this? The engine ran about 125 hours with 100 of them at Idle Trolling for Salmon. It never ran over 4000 RPM for more than a few minutes ever. Cruise speed is around 3500 - 3700 RPM. I did use a lot more fuel in that motor throughout the year too..
Thoughts? What are we missing?
Would like to figure it out before we put it back together again...
Has anyone ever heard of this? The engine ran about 125 hours with 100 of them at Idle Trolling for Salmon. It never ran over 4000 RPM for more than a few minutes ever. Cruise speed is around 3500 - 3700 RPM. I did use a lot more fuel in that motor throughout the year too..
Thoughts? What are we missing?
Would like to figure it out before we put it back together again...