Mike,

You got a BFH?

Know what? A big BFH is worth $0.60 Lb. I'm so far in the hole with this engine, if or when I get it to run my great-great grandchildren will be talking about it........LOL...lol...LOL
<']))))><

Mike is she running hot on one bank or both banks the reason I ask is I had a 60 degree looper do the same thing and basically went through the same thing you are going through but never found the problem. I came to the conclusion that the block was cracked up in the exhaust area but customer declined me of going any further and reason I felt like it was cracked was the exhaust tube up the down housing and up into the block was covered in white milkly residue.This engine was getting hot on the strbd bank and was normal on port side. Have you looked up the exhaust tube is it dry or milky. What I always say once you get your butt kicked like this you will never foget it but then again you probably will never see this butt kicking problem agian. Dont feel bad it happens to the best of us Good Luck

Yea, I've been in the exhaust tube and it looks like any other. A light coat of very black carbon and dry, dry, dry. Both banks are equal temp. By that I mean you can watch the Temp guage fluxuate 3-5degrees from side to side, depending on the thermostat opening and closing.

Have you tried this: www.ebay.com do a surch for 140hp 1989 Johnsons 25" Shafts then, place bid and hope for the best.

I'm talking about the Big F'ing Hammer (BFH), when I have something not working right, I walk over to my chest, pull out my 6 lb hammer, and just lay it next to what isn't behaving. I look at it and say, "ok, you @W($$&#(@, you better start behaving or I'm going to start wacking you with the BFH."

Shrug, it seems to work. After that, just the thought of the BFH makes things start running right.

I posted your problem on S & F and one says the powerhead gasket can cause this, another is saying to install the later model water pump assembly to increase water volume at idle, one is talking about a throttle controled water control valve.

I'm going to be pulling the powerhead, soon. If there is a problem with the base gasket, it should show up then. I've already installed the later model water pump housing that does not have the weep hole in it. They were suppose to build more water pressure, I've never (here comes my ignorance) heard about a "throttle controled water control valve". Is this like the High Pressure water springs in the thermostat areas? If so, I've shortened, lengthened, replaced (twice) those springs.
Oh by the way, I've got four of those , so called hammers, One is a tune-up hammer, two is an overhaul hammer, three is a replacement hammer and four is a "Honey I need a new motor" hammer. FYI. I've almost have worn out the first-three hammers on this motor...........

http://forums.screamandfly.com/forums/showthread.php?t=161456 you might want to look here:

Man I feel for you, Mike. BTW, those hammers are also useful on Harleys, along with bailing wire and a drip pan to place under them.

Did you ever identify the issue?

Not yet, I had to put it on the back burner for the time being. It seems like everybody else gets to go ahead of me, working on my own stuff takes second place. It will be front and center before the 17th July, as that it the Fishing Trip date.

Didn'tread every word from above, and hope there's no intake blockage.

I'm pulling the lower unit today. I'll get back later/.

Get you an infared thermometer and while it is idling, check all over the cooling system for a hot spot that may indicate an restriction that can't be seen. Also check the water stream temp and see if it really is overheating.
I had a Mercury once that the pee tube had cracked and let too much water by-pass when idling yet it cooled when running half throttle or more. The crack was inside the cowling and wasn't noticed till I took the cowling off and ran it. The pee tube creats back pressure to slow the water flow.
Hope you find the problem soon.

I might have whooped the beast. I closed the holes in a new water pump housing and siliconed the entire unit together. Once again did a flush and then a back flush thru the t-t hose and up thru the water intake pipe and checked for any debry in the lower unit intake. I'm idling with 15psi. and did check the pressure guage for accuracy. The port side still is building up heat. I removed the thermostat and housing, started the engine and you could watch the Niggira Falls. For sure no restriction. I changed the vernatherm and same thing again happened, I have now installed invert thermostats from a Mercury (slight modification to the heads)and am using the by-pass springs from a V-4 early model Johnson. Results::::: engine now idles with 12psi water pressure, temp will rise to 145degrees, then drop to 140. Next step is a lake test. cross your fingers.

"As the World Turns" has nothing on this. Good luck and thanks for keeping us posted.

WOO-WOO! Just got back from the lake. The engine did better than what I thought it would. I sat and idled for 15 min., temp stayed right at 140. Ran 5000rpm for 15 miles, temp stayed right at 145. Water pressure at idle-12-13lb. at 5000 rpm-24lb. Hey Nanny-nanny the wicked ole temp witch is dead. WOO-WOO!!!!!!! HIP_HIP HORRAY!!!!!!!! Look out fishes, here I come.......

So what you're saying is that the other thermostats were faulty ?...or due to some prior engine mods, you needed different thermostats ?

Glad you got yours fixed.

I fought a simular problem this week on my Dad's Four Winns.

Changed the impeller on the sea pump. Oh what fun. Had to stand on my head to reach the hoses under the block! After running it, it still ran warm. So I tore the sea pump back down, put it back together, and still warm. After a full day of screwing with it, I was furious. The engine in so crammed into that engine box, there isn't much room to work.
So with the 4th quickly aproaching, I blasted it with parts. I didn't want to keep changing one part, test it, only to find something else wrong. I changed the t-stat and put on a new circulation pump. Total cost was $80 in parts, but didn't have time to jack with it anymore. Was slammed at work. Ran it the entire weekend without a hickup!

Mike, too bad you're not selling them motors. As much as you've gone through them, dere's no doubt they are solid! Sure am glad to hear you got it whooped.

congrats on getting it sorted out. I didn't have any suggestions for you but was interesting to read the way you traced it down little by little. I learn alot from reading threads like this.

I just feel like the flaw is in the t-stat design. The style of t-stats in all the looper V-4 engines are such that the working part is surrounded by a heard of springs and plastic. We have had a lot of problems with the t-stats in all the looper style engines and have seen damage done to the ignition system as a result. (port thermostat controls the ignition system on looper style engines, during start up and increases or decreases rpm according to temp in that head) Most engines use a 143degree thermostat and only style is changed. If you adapt a different thermostat, as I did to this looper v-4, The only thing that I really changed is allowing a higher volume of water pass thru the head at the time of opening. The higher volume of water passing thru cools faster and better by flushing the heated water out more rapidly and more completely, thus reducing the residual heat that is built up in the metal. Or as we say here in my shop, "By golly it worked."
I do REALLY appreciate all the comments, suggestions and helpful hints that was offered during this ordeal. It just goes to show you that mankind is still willing to help others that need a helping hand. My hats off to all the TFFer's, ya'll are a great bunch of guys and gals. THANKS mike