overheating

[dblair256]

i have a 94 mariah talari 200z power by yamaha 5.0
never had problem with it overheating until the first trip of this season
on muffs without stat at idle does not overheat at all
replace raw water impellar, water pump, double check timing
but a soon as the get in the river temp just starts climbing
at 200 degree i shut it down as risers not hot check the oil its not that hot can
wipe it with my fingers but the intake is blistering hot at stat housing (no stat)

 

[ricovw]

Re: overheating

I read somewhere that someone else had an overheating issue with a yammie stern drive, and their problem was solved by cleaning a screen in a hose. I can't exactly remember where this screen is, or which hose it was, but I'm sure I read it on this site. Maybe do a search, or maybe someone else knows more? Sorry.

 

[ricovw]

Re: overheating

Okay found it, read this thread.

1991 EBBTIDE with yanmaha YEMS 4.3 litre over heating AGGGG!

You'll find it about 10 threads below this one.

 

[dblair256]

Re: overheating

so to update my overheating problem. finally found where i had put new upper seals in my outdrive the coupler between upper and lower unit was to big letting exhaust to be sucked back to the raw water pump. now the problem im having overheating when the rpm's are above 3k. the boat can idle all day perfect and below 3k some please help
i went and bought an infered thermometer and check engine without tstat.
riser: 132 and 134
exhaust manifold: 141 and 143
intake manifold at sendor unit: 128
guage reads 185 190 degrees

 

[Lyle29464]

Re: overheating

You need to put the Thermostat back in to do your tests. It does several things. The numbers you posted do not help. It does look like your gauge is wrong. If you are really overheating. ( steam, smell, engine is very hot, you may have a head gasket leak that acts up at high rpm.

 

[dblair256]

Re: overheating

it was the gauge some how i figured it out before i read your post, but thanks you were right on spot.
when to the water and ran great thanks for the help everyone