1991 yammie overheat

[mfo]

I have a 150hp yammie pro vee, that has had an intermittent overheat buzzer go off for the last 4 mos. it would happen when i was idling around for an extended time like 5-10 min at 5-6 hundred rpm the first time it happened I took it in and had the w/p replaced all was good until a couple of weeks later it did it again in the exact circumstances, ok this time I change both Tstats wasn't 2 weeks later bomm same thing so I get a IR temp gun and run it on the house for about 5-10min and boom again so I shoot the heads they were all about 130-135 on the left side standing behind and about 178-180 on the 3 cylynders on the right side ,what do you guys think is the likely culprit and the approximate cost for a shop to fix?



thnx
mark

 

[rodbolt]

Re: 1991 yammie overheat

most likly a sticking or defective pressure control valve grommet.

 

[mfo]

Re: 1991 yammie overheat

thnx for replying rod thats about the only thing I haven't changed out, but why the high temp just on the right side? and is 180 really hot enough to do damage short term like in 5 min?




thnx
mark

 

[mfo]

Re: 1991 yammie overheat

anybody

 

[rodbolt]

Re: 1991 yammie overheat

180 probably wont damage anything however I would quit doing it and fix the issue.
the stbd top bank is taller than the port bank.
if the pressure is low due to a defective water pump or a damaged/sticking PCV then the top of the stbd bank gets restricted or no water and overheats it.

 

[mfo]

Re: 1991 yammie overheat

thnx rod did i mention that I shot all three cyl. on the stbd side and all were 180 degrees top to bottom so would that still hold tru if even the bottom cyl was hot ?



thnx again
mark

 

[mfo]

Re: 1991 yammie overheat

ttt