opinions needed 87' 48 spl over heating

[juno pierrat]

have had a over heat problem when idling for 2 to 4 min. when this happens I'll idle up to 1800 to 2000 and alarm stops in 20 to 30 seconds. so I've chased the problem, new water pump, thermostat, pressure relief valve. this last weekend went in muddy river and pee hole clogged at water passage cover, soooo took cover off, very clean inside, no scale or crud, i use salt-away every weekend , cleaned elbow for pee hole, and will reassemble soon.

next step would be to inspect water passages in head, but i really don't want to do that, presently compression is 145 per cylinder. and after seeing inside water passage cover i would think head passages would be clean too.

fuel pump rebuilt 2 summers ago.use ethanol gas with treatment, use 5 to 10 gallons every weekend weather permitting, 60 hours a year

could this be a lean idle condition, causing temp to rise slowly, i have always had to pump bulb at slow troll or long idles.

 

[hunter200524]

Were all the water pump housing and plate gaskets ok?

 

[juno pierrat]

old housing and o ring in housing were ok impeller ok no missing or chipped fins but just noticed in parts break down that there is no paper gasket shown under impeller plate, and the kit came with one so i just put it in, same as 2 years ago when it was changed last. this gasket is ok i think

 

[juno pierrat]

fished today and took instant temp gun along, after running at 1200 to 1400 for awhile temp was 185 to 190 all around back of motor by spark plugs, bay water was 78, temps like this are to high, right?
may remove lower unit again and start to double check stuff

 

[juno pierrat]

No Title

well i found the problem, when the head was removed the gasket had a hole in it down close to the thermostat, so was not getting right flow, but the problem now is there was a large salt build up in this area, and after cleaning there is pitting in the head


sorry pic is upside down, so looking at upper bolt hole its to the lower left, and worse is by lower bolt hole to the upper left, the pitting is in the water area not around piston area, had 145 compression when taken apart
soooo is the head ok to use, i know not to use gasket sealer on the head gasket, but may be just in that area just as a little filler/sealer.

i think the cause of this i a little water sitting there during the winter and freezing, the old gasket 2 bubbles in this exact area, one with a hole through the gasket

need the advice from some of the senior techs

 

[juno pierrat]

bump

 

[jbcurt00]

Juno
Check your PMs

 

[Faztbullet]

Take it to a machine shop and you can have up to .030 milled off without problems,just take a piece of sand all cloth and smooth the chamber edge..