1989 wellcraft 3.7 mercruiser running 195 with no t stat

[stonyloam]

Re: ready to give up..

Re: ready to give up..

Did you check the thermostat, and is the thermostat in correctly? Could be that the t-stat is only partly opening.

 

[terryjoe]

Re: ready to give up..

Re: ready to give up..

i actually took out the t stat . thats what i dont get it runs as hot without it as it does with it in . crazy i ran it for 2 hours last night on muffs never got over 180 but put her in the lake and she will run if i let it 200/210 i shut it down most times at 195. maybe just set her in the front lawn and let the wife set flower pots on it renamed her TRAILER Queen

 

[wrestling coach]

Re: ready to give up..

Re: ready to give up..

It seems like you have been all over the place trying to sort this out. The above posts are sending you to places and techniques to find your way out of this.

1- Take the front cap off the heat exchanger. Look for old impeller pieces and the internal condition of the exchanger. Take some pictures and post them here for others to see. This is easy to do.
2- You have replaced the impeller but what about the pump housing? Maybe too worn even with a new impeller.
3- 195* is too hot. Put the correct 160* stat in it. Running a closed cooling system of any kind without the stat will not mean the temps will come down.
These three things are easy and cheap to do. If these don't get results or maybe some results we can move on from there.

Dennis

 

[terryjoe]

Re: ready to give up..

Re: ready to give up..

thanks i will try to get some pics tomorrow and post them.

 

[generator12]

Re: ready to give up..

Re: ready to give up..

i actually took out the t stat . thats what i dont get it runs as hot without it as it does with it in . crazy i ran it for 2 hours last night on muffs never got over 180 but put her in the lake and she will run if i let it 200/210 i shut it down most times at 195. maybe just set her in the front lawn and let the wife set flower pots on it renamed her TRAILER Queen

Running with the muffs, you have the water pressure in your hose to push through the system. On the water, you only have the lower unit's pump to do that. If it's running okay on the muffs and not so on the water (at the same engine load), this wound indicate to me that the lower unit water pump is not functioning correctly.

 

[terryjoe]

Re: ready to give up..

Re: ready to give up..

thats what im thinking.i took the inlet hose off the voltage regulater and tryd to blow back thru the hose i could but it was verry hard. im thinking it it should be a strait shot out to the lower waterpump could thare be something stuck from the waterpump to the hose that goes in at the gimbal berring? the impeller was shot and ive got no peices in the heat ex. i changed the hose from the outdrive to the elbow where it goes in the boat when i did the bellows boots and made shure it wasent kinked . on muffs i get a weak stream into the voltage regulater by weak i mean like a garden hose about half kinked. and water squerts out around the muffs.i was thinking maybe a cracked head or blown gasket but looks like it would run hot in the driveway if it was. maybe take the lower unit back off and look up where the copper pipe goes in i dont know loosing faith fast.

 

[stonyloam]

Re: ready to give up..

Re: ready to give up..

When you pull the outdrive, put your garden hose in the hole in the bellhousing and the one with the O ring and see if you get a full flow from there to the heat exchanger. If that is clear and flows easily look to your pump, may have to replace the housing along with a new impeller.

 

[terryjoe]

Re: ready to give up..

Re: ready to give up..

thanks i think i will do that tomorrow. i was lying here thinking that verry thing it should have unrestricted flow .