More post install questions Mercruiser 5.7

[Triple502]

So for those that have been following my saga, I did my first engine swap. The boat is a 1995 Maxum 3200 SCR cruiser with twin Mercruiser 5.7 270 hp Bravo II drives with Thunderbolt V ignition system. So after I did the swap and got the motor running, I followed the advice on this forum and set the timing. The motor was running a little warm on the hard with the hose (195 degrees). Once I splashed the boat I took it to the slip and just ran it lightly at the dock for 3 weeks (the weather here in MD hasn't been great this spring). Anyway, I finally took it out for a run today to put a load on her to see how the new engine performed. I had a few people aboard and left the marina with no issues while idling out the channel. I tried to get the boat on plane and even with the trim tabs it just wouldn't do it. Neither motor would turn past 3200 rpms. My question is would one motor hold the other back if it's not reaching it's potential? The new replacement motor may need some fine tuning but I cannot figure out why the other motor won't go above 3200 rpms. Any suggestions? Also, the new motor is still running warm in the water. I will go ahead and replace the impeller in the sea pump and double check that I put the correct thermostat in. I will replace the fuel filters, regap the spark plugs and check the wires and timing. Thanks in advance.

 

[Bondo]

Neither motor would turn past 3200 rpms.

Ayuh,..... Sounds like rotten gas to me,....

 

[Triple502]

What about the warm temp on the new motor? Will the incorrect timing affect the temp of the motor? If so is it too far advanced or not enough? Thanks.

 

[Triple502]

What I learned today. I changed fuel filters and there was some crud that came out of them. I took 5 gallons of fresh gas and hooked it up remotely to both motors. The old motor would reach over 4000 RPMs while the new one topped out at about 3400. A slight improvement over Sunday. The gas did not smell foul or varnished so not sure what's going on. I am thinking the carb linkage or timing needs adjustment? I should note that I had 9 people aboard on Sunday and today it was just me and the dog.