cold water and thermostats

[dingbat]

I've got an 87-175 Hp that every spring that has an issue with water flow out the pisser. We fished a 3 day tournament last week and the same old came back again. Even though we had 15 lbs. of pressure, at idle I only get sporadic spits out the Telltale and when bumped up to say 2500-3000 rpm I got a "small stream" but not what I would call a good flow. I proceeded to tear the thermostats and poppit out for inspection but found nothing wrong with neither. I put it back together and ran about 3 miles out had a good strong flow of water out the exhaust ports but the flow out of the telltale was still weak. Concerned, I opened the covers to manually check the head temperature and found them just warm to the touch so the heads where obviously getting cooled somehow or they would have been hot. <br /><br />I ran 15-20 miles out each day and then trolled another 10 hours or so each day without incidence so this has me perplexed. I’ve got good water pressure so the pump appears to be alright. The only thing I can think of is that the thermostats are staying closed due to the water temps (53°) and the only water passing through the telltale is from the thermostat vents.

 

[ehenry]

Re: cold water and thermostats

You're correct on that, DingBat. I notice my engine doing the same thing and like you, I pulled the thermostat and checked it and found no problem. I buttoned everything up without the thermostat and let it idle for a minute or to and had a strong stream the instand it cranked for the entire time i let it run. I put the thermostat back in and haven't worried about it since.

 

[dingbat]

Re: cold water and thermostats

Thanks,<br />You save me some time. The next step was to pull the thermostats and see what happened.

 

[Laddies]

Re: cold water and thermostats

I think that the newer thermstats are vented with with a small v opening on the plunger and I have seen some thermosatats with small holes drilled in them to vent them--Bob--- it needs the thermostats to cool properly

 

[Coolmaker]

Re: cold water and thermostats

Actually it needs the t-stats to get up to operating temp (143 degrees)... and to have proper water pump pressure at idle.