Should I change the thermostat in my 73 115hp JN

[teslaman]

I recently installed a rebuilt powerhead and rebuilt the carbs. when I removed the old powerhead, it didn't occur to me to install a new thermostat. I'm not sure how difficult it will be to do with the new powerhead on, but should I consider installing a new thermostat at this time?

 

[WillyBWright]

Re: Should I change the thermostat in my 73 115hp JN

I assume there are two, yes replace. You should replace your water pump if you haven't already.

 

[reeldutch]

Re: Should I change the thermostat in my 73 115hp JN

When you do a rebuild ALWAYS change the thermostats.
no matter what engine.

 

[tashasdaddy]

Re: Should I change the thermostat in my 73 115hp JN

why rebuild and engine, and cool it with old parts. they might have been part of the reason for the rebuild.

 

[ezeke]

Re: Should I change the thermostat in my 73 115hp JN

It's a pain to change, but you really need to do it. BTW, there is only one vernatherm.

 

[teslaman]

Re: Should I change the thermostat in my 73 115hp JN

Sounds like I need to change them then. What all goes into changing them? Can you et to them by removing the bottom cover?

I replaced the water impellar about 6 months ago. The pump housing was old, Should I go ahead and replace the entire pump? Do one of you know the part# for a new pump housing if it is needed?

 

[ezeke]

Re: Should I change the thermostat in my 73 115hp JN

The whole pump kit is part # 439140. The housing is #389157. Get the kit - it is a much better deal.

Hard to tell what you will run into on the thermostat. Best to get the parts breakdown from your dealer and come back with the list after you open it up. Minimum is the vernatherm - part #384719.

 

[teslaman]

Re: Should I change the thermostat in my 73 115hp JN

I looked at a part list on ishopmarine.com and these are the available parts I found.

308070 vernatherm valve
305591 spring, vernatherm valve
384719 vernatherm
318395 check valve
318396 gasket housing
318394 gasket

Would it be best to replace all of these parts? I remeber looking at these parts whil installing the rebuilt powerhead but I'm not trained enough to tell if they needed replacement or not.

 

[teslaman]

Re: Should I change the thermostat in my 73 115hp JN

Is there a good place online to purchase part 439140? iboats and ishopmarine do not seem to have it.

 

[ezeke]

Re: Should I change the thermostat in my 73 115hp JN

When you enter the number on ishopmarine, put a zero in front - 0439140.

You would probably get just as good a deal from a local J/E shop considering shipping cost.

Try the locator, check the third circle and put in your zip code:

http://dealerlocator.evinrude.com/EN/?Rnd=1171572265046

 

[teslaman]

Re: Should I change the thermostat in my 73 115hp JN

Thanks

 

[tschamp20]

Re: Should I change the thermostat in my 73 115hp JN

hey tesla i to just ordered vernatherm from ishopmarine.i cant imagine needing any of the other pieces unless they show obvious wear.such a simple design.you know.
hows the build going,almost ready for the maiden voyage?im waiting on a warm enough day to paint the block,been in the 30's.sux im itchin to finish this puppy. im glad i decided to do this my self,ive learned so much about my motor.
as a side note on your link n synch thread,where i live in s.e. virginia our town is a watermen town(fish,crab,oysters,clam) all the people ive spoke to look at me like im crazy when i say link n synch. in all these years theyve never done it. makes you wonder how theyve lasted this long. oh and when i say i read about it on the internet they think im some dumb yuppy(far from it).silly old bastards!lol
peace out

 

[teslaman]

Re: Should I change the thermostat in my 73 115hp JN

Thats funny stuff! Yep, I've learned a ton from doing this work myself too and have probably saved a buttload of money in the process.

I wonder how difficult it would be to replace the vernatherm with the block installed. If I remember from the installation if I remove the the neck cover and loosen the bottom plate I can probably get to it.

Anyway, I have some more stuff to do. I did get a copy of the manufacturer's manual (very helpful). I've ordered a new fuel pump and I'll blow out the fuel line and syphon the tank. I've got to install a fuel/water seperator and a new vernatherm. After that it should be ready for link/sync. I'm thinking about getting a local shop to do that for me though. Oh....I may go ahead and install a new waterpump. I just put a new impellar and bottom plate in 6 months ago though, so I don't know.

 

[ezeke]

Re: Should I change the thermostat in my 73 115hp JN

I haven't used my 1973 engine much lately, but I keep the 1976 115 up and the vernatherm and housing are the same as yours. Because of the salt, I check the thermostat every year.

If you can get the bolts loose, you can do it without pulling the engine, but, it is a lot easier if you cut or drill access holes in the lower cowl. You can drill the corners and make the intersecting cuts with a Dremel, or just make round holes large enough to allow the socket to reach the bolts. Once that is done you can reach the bolts straight on.


I cover mine with Black Epoxy, but you could make or buy access plates or covers. There are several kinds of round snap- in inserts made for cars that will work.

 

[teslaman]

Re: Should I change the thermostat in my 73 115hp JN

I guess I'll have to look at it to better understand what your saying.

About the black epoxy, are using it instead of a gasket?

 

[ezeke]

Re: Should I change the thermostat in my 73 115hp JN

If you cut the lower engine cover [cowl], you will want to seal it so that water does not enter. That is the idea of the plugs or epoxy.

Once you change the vernatherm once, you will understand perfectly. It is about as easy as replacing the shift rod on your motor with the carburetors in place.

 

[teslaman]

Re: Should I change the thermostat in my 73 115hp JN

Gotcha!

 

[Texasmark]

Re: Should I change the thermostat in my 73 115hp JN

I lost a powerhead (froze up) once on a '75 3 cyl Rude because I didn't know it had a stat, (didn't have an overheat warning device either) much less know to change it frequently.

Mark

 

[teslaman]

Re: Should I change the thermostat in my 73 115hp JN

I just got a chance to remove the cowl and remove the vernatherm housing. Access to the pieces is not a problem with the block installed.

Although a bit dirty, the parts look OK. I'm going to go ahead and replace all the parts I can get. The check valve spring seems to be the only part N/A. The vernatherm is approx $30, everything else adds up to about $50 including the hoses.

When instaling the housing gasket and plate gasket, should I use any sealing compund?

 

[ezeke]

Re: Should I change the thermostat in my 73 115hp JN

You don't need sealer. It will make it easier to check periodically if you don't use it. The pressure is light.

Is the old check valve spring OK?

I got all of those parts from a company is Seattle:

Sea Way Marine
2501 Harbor Ave. S.W.
Seattle, Wa. 98116
800-332-0803
206-937-1787 FAX
pauls@sea-way.com