2.5 245 Cooling issues....

[Arizona Hotboater]

2.5 245 but has a poppet valve and t-stats. The right head heats up much faster than the left and reaches a higher temp. The right hits 180* and the left, only 150*. When I sit and idle after a run, the temp in both heads returns to 120* or so, but the right head cools down slower.

I pulled out the t-stats and put in 1/8th" restrictor washers. No change. When I opened the poppet valve last week, I did notice there were some very small pieces of vegetation in it. Not much, but it was there. Could there be a blockage in the water passages of the right head? The water pressure is OK and the t-stat dump tubes flow like a garden hose, so any blockage has to be after the t-stats housings. I have dual temp gauges...one for each head. I just put the senders in a cup of hot water and the gauges reached the same temperature at the same time. Obviously the senders and the gauges are fine...the right head is just getting hotter than the left.

The water pressure is only 7-8 psi at 3000 rpm, but at 95 mph its about 20 psi. I bought a new impeller today. I am thinking there must be a blockage in the right head cooling jacket.

Any thoughts anyone?

[captcarb]

My vote is for trash in the holes between the exhaust divider and the right side of the block. It could be elsewhere.

The flow out the right thermostat housing may be most of the flow for that side. The poppet keeps the pressure up.

Jim

[Arizona Hotboater]

Thanks for the input Captn.

Welp, I pulled the right head. Its clear. Air easily goes thru it so water will too. The passages from the exhaust divider to the right cylinder cooling jackets look clear from what I can see, but I need to pull the divider for a better view.

[Arizona Hotboater]

To the top.

Hey Greg and John! Any help would be appreciated.

[Greg Moss]

Been tring but the board hasn't been working with me. I think I will have to go and find what I sent Greg To post about how i do my cooling he doesn't seem to want to put it up. I don't think you need the poppit or the t-stats. Put pipe plugs where the Hoses come out of the heads. Let it flow alot of water. That is the trick. was checking my motor temps acouple day ago. The spark plug bases were all 109* every one of them. My motors don't get no where near 180* that is too hot. I have been reall busy and am sorry I haven't had time to go through and send you the info on how to do the cooling like I do you need to do it and you will not have anymore problems. Maybe Greg Will read this and send it to you. I will try and get it all togetherm and send it to you. Do you still talk to Mark linn he has it all he may still have it where he can send it to you. He did his motor and it worked great!

[Arizona Hotboater]

Greg,
I still talk to Mark on occasion. He no longer has the info on computor to send to me. I know I had to rewrite it. I asked him a while back.

Heres the thing, the motor ran right at 145* a month ago. The next time I took it out, it ran 180* in the rt head and 155+ in the left. I dont get it. I guess I'll pull the divider and see if any junk is in there. Another Idea I had was put a garden hose on the water tube...(I have the lower unit off). I took off te rt head. I can duct tape the cylinders shut leaving the cooling jackeys open. Turn the hose on and see if water flows to the rt bank from the divider. If that checks out, I figure on bolting the head back on and removing the poppet valve. and turning the hose on again.

I intend to remove the poppet valve. I need either a round poppet cover (I have the long type now) or a poppet block off plate. $70 from merc. Maybe Ducky has a spare round poppet. These can be plugged easily and used instead of a block-off plate.

Thanks for the reply.
Marc AZH

[Arizona Hotboater]

OK, I have flushed out the cooling system. I did the duct tape deal on the rt cyl bank and there are no obstructions to flow. Water comes out of the divider like a fire hose. I bolted the head back on and removed the relief valve assembly (poppet) and flushed that also. No obstructions. Either the obstruction has been cleared (if there was one) or there is another problem. Ducky gave me an old poppet valve cover plate with which I will make a block off plate. I will remove the relief valve assembly completely if the problem isnt solved. I want to run it one more time with the poppet to see if the problem was solved by flushing the system.

Wish me luck.