too hott

[mickey117]

i have 86 erude 90 hp when i was running it on a hose.i just noticed that one side of the motor was hotter then the other.i also niticed that the water coming out wasn't warm (it was cold)should it be warm?i know on someother motors that the water comes out warm why isn't mine?is it suppose too?anyway i don't think one side is suppose to be hot and other not.shouldn't i be able to touch the motor and keep my hand on it ?

 

[tashasdaddy]

Re: too hott

you have a tstat for each side. should be 143 or so degrees F.

 

[ezeke]

Re: too hott

The tell-tale is there to let you know that the water pump is working and not much else.

The pump forces water into the cooling circuit of the engine and the rest of the water bypasses. At any time the thermostats may open and close as the engine water reaches 143 degrees, allowing the heated water to pass out with the bypassed water and a fresh supply of cool water to enter from the pump. The water at the tell-tale could be cool or warm depending on that, but it would always have some bypass water so it should not run hot water unless you were running at higher RPM and under load.

Typically, crossflow motors tend to run a little hotter on one bank than the other. If it is a large difference, check the thermostats and relief valves. You can test the thermostats with a meat thermometer and heated water on a stove top.

If the thermostats and relief valves are OK, check the water deflectors in the cooling circuits.

Yes, you should be able to keep your hand on either bank of cylinders for three seconds or more. The alarm will not sound until the temperature reaches around 211? F.

 

[mickey117]

Re: too hott

what is the tell tale?is it the water that comes out of the motor?and not to sure how to test w/a thermometer and the stove.also not i'll have to look into the deflectors.Could a deflector get stuck?or do they go bad ?

 

[ezeke]

Re: too hott

Tell-tale, overboard indicator, pisser, or whatever you want to call the outlet on the starboard side of your lower cowl.

To test a thermostat you need to gradually increase the temperature until it opens, while watching the temperature. You can get real sophisticated, but a pan of water on the stove with a meat thermometer in it will work fine.

The older deflectors often need to be replaced. If they move or go bad, the water does not circulate around the cylinders evenly. You need to remove the cylinder heads to check them and then you have to replace the gaskets.

 

[1FASTLASER]

Re: too hott

ttt

 

[mickey117]

Re: too hott

how you remove the tstat from motor.could you just simply feel the hose coming off the tstat cover for water to see if water is being passed thru or is there another way to check tstats operation w/out removing

 

[Joe Reeves]

Re: too hott

If you intend to keep that engine for some time, I'd suggest that you purchase a service manual for it to avoid costly mistakes. There are no short cuts without chancing disastrous results.

Replace both thermostats and remove the cylinder heads to change the deflectors.

(Water Deflectors)
(J. Reeves)

Water deflectors are actually lengths of 3/8" outside diameter rubber hose, installed between the top cylinder and any cylinder beneath it, and also between the bottom cylinder and the block. The purpose of the deflectors is to have the water follow a definite path around the cylinder walls. Unfortunately the deflectors between the cylinders will at times swell sideways due to either a previous bad overheating problem, or simply due to age and salt corrosion. This causes a water flow restriction which usually allows the water to cool sufficently at low rpms but not at the higher rpms.

This hose material can be purchased reasonably at any automotive parts type store if you care to make your own, or you can purchase individual deflectors at any Evinrude/Johnson dealership at a somewhat higher cost.

Removing and installing them can be a hassle at times, but not always. I use a sharply pointed scribe with about 1/4" of the tip bent at a right angle whereas I can reach in, jab the tip sideways into the rubber, then yank it out. It's necessary to clean the seating surfaces where the ruber contacts the block with a small rat tail file to eliminate salt deposits etc. When installing the new rubber deflector, coat the deflector and the metal surfaces with WD40 which will act as lubrication to allow it to go in as easily as possible.

Make sure that you insert something into that deflector area before cutting and installing the deflectors if you make your own so that you will be certain that they are the right length and also that they will be seated properly. Usually a very small amount will be left extending about the block sealing area..... simply cut the excess off with a single edge razor blade.

 

[mickey117]

Re: too hott

well (too hott )turns out to be (too cold )the one tstat seems to be stuck open cooling the motor to much.which in return i heard is not good.will make the motor idle rough.anybody ever hear of this?

 

[HighTrim]

Re: too hott

Stuck open is a problem, same idea as removing the t stat all together. Joe Reeves explains it best from this post.

Many engines are considered high performance engines and demand a thermostat(s), and many smaller hp engines also require a thermostat for the following reason. The pistons actually distort/twist off round when running. The thermostat is required to keep the outer wall surrounding the steel cylinder, and the cylinder wall itself at a temperture to compensate for the distortion.

With the thermostat removed, the difference in temperture between the inside the cylinder and the water jacket quickly reaches a point whereas (in effect) you have a oblong piston running up and down a round cylinder, or vice versa. Bottom line is without the thermostat, the piston and cylinder wall could be damaged in a short period of time.