I replaced the thermo. on both heads and ran the motor for a bit. The port bank is about 125* and the starboard bank feels like a room temp beer. I use the motor in salt water and I bought it used. I did get it hot once, got into some kelp and the buzzer went off along with a cloud of ???. but restarted and it ran fine. I did a comp. test 119 _121 psi. Does any one have a comment or had a similar experience ?
It can be a mystery. I know many times each bank on a V6 or V4 will exhibit different compressions. And it will run fine as long as the starboard bank's compression is even as well as the port bank, even if the starboard and port are not withing the 10% limit. Example:1,3,5~1152,4,6~100 or even 95
just a contribution, may not be exactly what you are experinecing. I found an internal "hole" in the head cover gasket of my yamaha. One (at least) role of this gasket is to prevent the cooling water to flow except if the thermo is open. when this gasket is blown, the water is no longer controlled by the thermo, it runs through the hole and keep cooling this side of the engine regardless the thermo.This gasket has a metal core, i guess steel (not stainless) it was badly corroded and the high water pressure (contribution of a stucked- closed defective bypass valve) produced the hole.This is my theory from what I see now I am dismantling my engine ("see 1991 200 hp yamaha broken bolts nightmare") BUT I am pretty convinced that big temperature difference in an otherwise ok firing engine is due to big difference in cooling water flow.If it is working just let it be, dont risk to go through what I am going now!good luck and keep the posting going!Frank
thanks guys, Fjbango I have been following your journey, buddy - - - if I were you I would hire someone to steal that thing. Leaving mine alone sounds good. If I ever meet GOD I will ask him to please make the 2nd commandent " THY SHALL NOT HAVE TO WORK ON ONES OUTBOARD".
On my 200hp V6, the starboard head is always warmer than the port side. The water enters the PH and flows thru the port side before going to the starb side, so the water is already pre-warmed before it enters the starb side of the motor.Maybe someone ( Ray, Rodbolt ) can tell us if the water flows differently in the V4's.
Hello everyone, I am curious myself. I own a 1989 Evinrude SPL V-4 88 horsepower crossflow. What mine does is after I warm it up say 5 minutes at idle speed my heads get hot . I can hold my fingers on the heads for about 4 seconds before I have to remove them on both heads. Yes, I think the starboard bank is hotter than the port bank.
Canuck 16, I changed my water pump out last year in March 2005. It pees a good solid stream out of the tale-tale, but cools down excessively when I rev it up somewhat, but not over 1,500 rpm's for fear of running away motor.