Evinrude 88 SPL overheating (pics)

[reeldutch]

Re: Evinrude 88 SPL overheating (pics)

sometimes yellow jackets crawl into the idle relief ports and start building nests in there.

you should be able to blow everything out while you have the lu off.
stick the power washer in there and give a couple short bursts.leave the tstat housing off. while doing this.blow trough the idle relief ports also.
when i rebuild a motor and before i install the ph
i just blow out the hole midsection and give it a coat of paint.

those darn yellow jackets get into the weirdest spots.

good luck

 

[HighTrim]

Re: Evinrude 88 SPL overheating (pics)

Make sure you do put those t stats back in, although it sounds as if you are. Pistons warp while running. The tstat is required to keep the pistons outer wall, and the cylinder wall itself at a temperature to compensate for that said warping.

When you remove the t stat,you could basically damage the piston and/or cylinder wall in a heartbeat. This is due to the fact that the difference in temperature between the inside the cylinder and the water jacket quickly reaches a point where you basically have an oblong piston running up and down a round cylinder, or a piston running up and down an oblong cylinder.

If the bean counters could have left the t stat out, they would have. It is there for a reason and should not be removed, even in Florida.

 

[pdrayton]

Re: Evinrude 88 SPL overheating (pics)

Reeldutch - what's the "Idle relief port"? and where is it?

Hightrim, thanks for the info, I'll make sure to put those thermos back in.

 

[guy74]

Re: Evinrude 88 SPL overheating (pics)

The Idle relief ports are the openings on the back of the midsection that exaust comes out of when the motor is idling in the water. The water from the thermastats exits there as well as to the prop.

 

[HighTrim]

Re: Evinrude 88 SPL overheating (pics)

Little critters also love building nests in my tell tale nipple. Every spring I have to clean that out.

 

[pdrayton]

Re: Evinrude 88 SPL overheating (pics)

UPDATE: Took the boat out fishing and drove it at 3000 -4000 RPMs for 15 minutes then measured head temperatures. Starboard head ~140F. POrt ~120F. Remember, I don't have any thermostats or pressure valves in the thing (haven't got the urge to fix them yet).

So it seems the original problem of overheating is fixed. Wish I knew what fixed it. I have a feeling it was the water pump. Even though the impeller and all seemed fine, perhaps it wasn't.

Question: Considering there are no Thermostats in there, is the difference in head temperatures an indicator of a problem? As far as I can tell, the water flows through each side of the V4 independently so they should be the same temperature, no?

 

[Chinewalker]

Re: Evinrude 88 SPL overheating (pics)

It is a fluke of the design that makes one head warmer than the other. They all run like that... Part of their charm, I guess...
- Scott

 

[Benny1963]

Re: Evinrude 88 SPL overheating (pics)

hey pdrayton how ya doin man you might want to go ahed and put those thermos and poppetts in it will be worth it trust me you dont want to risk your power head
bennyb

 

[pdrayton]

Re: Evinrude 88 SPL overheating (pics)

Yeah, thanks for the push. I do really need to put them in. Been putting it off. Got lost in the fog and almost spent the night on the boat last weekend. And then, if that wasn't enough, the clutch on the truck finally gave out and I couldn't get it out the water when I did eventually get it to a dock the next day.

So the truck is in bits, and thermostats are trailing a distant second to a new clutch!

 

[pdrayton]

Re: Evinrude 88 SPL overheating (pics)

OK, so I"m going to be a good boy and put the tstats and poppets in. Is this all I need, considering when I opened the tstat housing there were no tstats or poppets. All four holes were open.

Poppet valve
http://www.iboats.com/mall/partfind...gd_row=5&keywords=poppet&**********=521284852

Thermostat kit
http://www.iboats.com/mall/partfind...gd_poid=111072&gd_row=34&**********=521284852

Is that all I need? Don't the poppets need a spring too? Is poppet a synonym for pressure valve?

I don't see how it works though - the flow through the heads doesn't start until the water heats up at the cross plate?

Anyway, please let me know if I need anything else in addition to these two things. Thanks.

 

[flabum]

Re: Evinrude 88 SPL overheating (pics)

That is all you need. Remember, when you put the thermostats in, the thermister (long side) goes towards the rear. Use plenty of gasket sealer on the bolts to keep them from rusting too fast

 

[Solittle]

Re: Evinrude 88 SPL overheating (pics)

The springs are for the poppits not the t-stats. You need to put a light coat of sealer on all the gasket surfaces. Follow the diagram for assembly exactly. When you get things assembled I put tie wraps around the assembly and put it in my vise with very light tension and leave overnight. The purpose of this is to give the sealer a bit of time to cure and hold all the parts together. It would be helpful to get a friend to give you a hand when you go to install the assembly. One guy positions and hold the assembly and the other starts the three bolts. When the bolts are well started cut the tie wraps.I found this necessary due to the temsion of the springs. I don't have enough hands.

 

[Lakester]

Re: NO thermostats?!!???

Re: NO thermostats?!!???

And there are no thermostats in there. No pressure valves either (see the attached picture).


So what's the deal? Should I have thermostats, and should the right hand most hole be letting water through and down to the LU drain holes?

Thanks

hello,

that is exactly what i experienced when i took off my Tstat housing cover on my 1971 85HP evinrude... NO vernatherm components. but Left side valve and spring there.

so by chance i had oppty to visit with shop the seller had used. they said...

run and check head to be 130F. if so, u are fine. my book says it circulates at 140F but shop guys said to measure it to be 130F. if 130F u r ok...

engine appears to have been run this way for years... am in so texas.

personally, i like the idea of the Tstat innards and running head water, then lake water as it opens and closes...

but, why would a good shop remove them?

and while on the subject, why do outboards run in the 130-140F range when an auto engine runs much hotter?

wondering...

regards
lakester

 

[pdrayton]

Re: Evinrude 88 SPL overheating (pics)

Thanks for the tips. I like the idea of putting it together in a vice overnight - no point hassling with that tiny area and springs and all. Poor engineering if you ask me.

The one head was at 140F so I think I'm ok (other was 120). I went to order the stuff but there is only 1 poppet available, so I'll wait til they have some. Seems like it may not be optimal to run the engine without tstats, but it's not the end of the world either.