SOLVED!
As you can see from previous post, I pulled the heads off and found hard build up in the water passages. I scraped and vacuumed out all that I could back to base meatal. Id say i got at least 95% of it out. Put it all back together with new gaskets. I was very fortunate to get the service manual for the boat.
Ran the boat today, after some tweaks it ran for hours with no problems. So happy to be able to finally enjoy my new (to me) boat.
Tips/details,
1. On reassembly i had an issue with the Port engine running rough and making a metallic ticking noise, similar to what you would expect from a bad rocker arm(engine doesn't have rocker arms. Long story short when i was cleaning the heads, one of the pad pads under the lifter came unseated. I initially thought i messed up the timing. but after pulling each valve lifter i found this one unseated. put it back and problem solved, no damage fortunately
2. I was able to perform this job without pulling the engines out of the boat. It is kind of tight in places but its doable.
3. I used a Swedish pipe wrench (from HFT) just behind the motor coupling to rotate the crankshaft to set up timing. It was the only thing to get a reliable bite in the tight space. This kept me from having to pull the front cover of the engine.
4. This is a relatively simple engine, Torqueing the block and setting the timing was straight forward. The hardest part was reinstalling the chain tensioner. the service manual was extremely helpful and watching a couple of youtube videos was made the difference. There was a video out of Russia that i found most helpful. He didn't have fancy tools or excess commentary, he just did the job. If you have a decent collection of tools i wouldn't be intimidated to tear down the heads
5. Chain tensioner - You have to compress the oil & spring driven piston and lock it into place with a built in tension ring to be able to reinstall it. Once you have it reinstalled and the you have set the timing, reach down to it with a long thin screw driver or piece of 9wire and pull the piston out. Just a little force will do it. This will make it hold tension on the chain immediately, otherwise it wont due so until oil has been pumped into, which leaves a small window of time for the timing chain to jump.
6. I used a dial indicator to check to ensure i had top TDC (top dead center) of the cylinder but it can be reliably found and set during disassembly using the cam shafts have timing marks. Drop a long (10") socket extension into the spark plug hole of cylinder #1 or
#4, it will stick out. Rotate the crank until the extension is sticking out the most, then fine tune it by referencing the cam shaft timing marks ( lined up on to and which match marks on cam journals). The cylinder is now TDC. Just take care not to rotate the crank at all. I made a reference mark on the engine coupler with a sharpie as a quick easy check.
7. Setting the timing was easy after i figured out those tricks. I laid the cams in the with the timing marts oriented as i could and the cam lay in flat/level. I then put the journals on but only snugged them, just enough to make all the mating surfaces. I fine tuned them by holding the chain up and rotating the cam using a 10mm wrench on the cam sprocket bolts ( they are not easy to rotate) so that the timing refence marks were oriented correctly. Remember when your done to have all your chain slack on the Intake side. the tensioner will take it out when you install it (#5). The Exhaust side and top should be nice and taut and seated on the sprocket teeth. -Also dont forget to use liberal amount of assembly lube, i recommend Ultra Slick.
8. When I was all done and initially ran the boat I eventually got overheat alarms. I pulled the thermostats and found some loose material hung in them and causing some blockage to water flow. I pulled the thermostats for now to blow out any other loose bit. I'll put em back in at the end of the summer. Boat ran great after that, (16+miles)
Thank all of you for your help!
