What should I buy to change the thermostat on a 90hp v4 Evinrude?

[Skidooosl]

I am about to change the thermostat on my 1985 E90MLCOS V4 Evinrude and would like to know what all I should replace... it looks like this motor has 2 thermostats? can I just change the 2 or do I need to replace anything else while I am in there?

 

[Walker]

Re: What should I buy to change the thermostat on a 90hp v4 Evinrude?

Buy a "KIT". If you are going to the trouble of changing the T-stats you might as well change the bypass valves too. The work is getting the housing off and back on. There isn't much room to operate down in there.

 

[ob]

Re: What should I buy to change the thermostat on a 90hp v4 Evinrude?

I agree with Walker.Closely inspect and or replace the relief valves and springs while you're in there.Also ,consider the waterpump if it hasn't been serviced in two or more years as well as the water deflectors under the cylinder heads.That will involve replacing head gaskets and retorquing head cover bolts.

 

[snipe401]

Re: What should I buy to change the thermostat on a 90hp v4 Evinrude?

Not sure where you live, but if the engine isn't run in very cold climates you might just want to eliminate the thermostats. They go bad and clog up so much I eliminated mine years ago. Took a bit to get them out, but I just put the new gasket on and did away with thermostats all together.

My 1987 Johnson 110 hp 4 cylinder outboard didn't miss them a bit. Increased water flow through the system. Better cooling. Runs great, and never overheats. I even replaced the rubber water lines at the back of the engine with clear plastic tubing. Now I can visually check any time I want.

Just food for thought.

 

[Walker]

Re: What should I buy to change the thermostat on a 90hp v4 Evinrude?

Do not eliminate the T-stats. Your motor was designed by engineers to operate at a certain temperature range and thats what the T-stats ensure happens. Running at cooler temps (without T-stats) will excellerate coking and shorten the life of your motor.

 

[Skidooosl]

Re: What should I buy to change the thermostat on a 90hp v4 Evinrude?

I have already purchased the 2 thermostats for the engine but does OMC offer a kit? If so this is the way I would like to go. I just replaced the water pump with the full kit and if so would like to do the same for the thermostats? trying to make the motor as reliable as possible. What is a water deflector? Is this a normal wear item? If so I will replace this as well. Let me know if there is anything else in this outboard that I should be looking into. I live in Michigan and often will be out on the water when the temps are in the 20?s / 30?s in the fall and water temp is sometimes < 40 or 50 so removing them would not be an option but would like to do everything to keep this motor running top


I was told the carbs were also rebuilt last season

 

[ezeke]

Re: What should I buy to change the thermostat on a 90hp v4 Evinrude?

It does not matter where you live, the water is never warm enough to run without thermostats in general use of an outboard.

The water deflectors are in the water passages of the engine. You have to pull the cylinder heads off just to inspect them.

 

[johnson1989]

Re: What should I buy to change the thermostat on a 90hp v4 Evinrude?

If your not having an overheat issue it is probably not necessary to inspect or change the deflectors. Head gaskets are a little spendy, and you need to make sure to clean the mating surfaces well and torque to ratings. If you don't mind the cost and time it never hurts to inspect. I did have to do all three on my 89 110HP due to overheating. Pump, Stats, and Deflectors.

There is stat kit available. I did the whole kit which included new gaskets, springs, stats and valves. The stats are a bear to get at, having two people help. Since you did your pump i would assume you already have gasket sealer, I used permatex. I just removed the lower cover to give me some room to work and got the cover, stats, valves and gaskets in place,then had another help squeeze the springs in. I have heard of others using tie straps to keep everything together. Here is a thread that did that.

http://www.marineengine.com/discus/messages/12478/21607.shtml

If you don't have a manual you can look up your kit and diagrams here

http://epc.brp.com/default.aspx?brands=ej&lang=e

As far as snipe401 I wouldn't listen to a word he said below

Good Luck

 

[Solittle]

Re: What should I buy to change the thermostat on a 90hp v4 Evinrude?

Use an extra long 1/4" drive extension with a universal and 7/16" socket for the center t-stat cover bolt.

For what it is worth I would not run my 1987 110 hp twins without the t-stats. There are quite a few posts on this with convincing reasons why.