Is 195 degree's or so too hot? 2.5 liter

[shelbydriver]

My motor runs cool under high throttle but in the ocean at around 3 k rpms gets hot. Heads hot to touch. Looking at 195 or so. Checked most things. Can I let it run this hot? Is the temp gauge off?

 

[KCLOST]

Re: Is 195 degree's or so too hot? 2.5 liter

What year is your motor?

 

[BillP]

Re: Is 195 degree's or so too hot? 2.5 liter

Water temps at 195F are too hot for salt water. Salt begins to crystalize before that temp and will eventually plug the water passages. Approx 140F is the breakoff point to keep salt suspended in the water.

 

[shelbydriver]

Re: Is 195 degree's or so too hot? 2.5 liter

Its a 94 carburated motor. I am having the same problem as someone else on here. I saw they replaced the gasket under the block and they fixed there problem. It runs cool under high speed. But temp rises at cruise.

 

[The Marine Doctor]

Re: Is 195 degree's or so too hot? 2.5 liter

The T-stats you have in your heads are made to open and regulate the heat to 143 deg.<br /><br />If at WOT you can maintain this temp, I would think that at the lower rpm range there is either a restriction or a weak waterpump.<br /><br />TMD

 

[shelbydriver]

Re: Is 195 degree's or so too hot? 2.5 liter

thanks TMD, I did change out the impeller a couple of times. Also the upper water pump and lower housing. I will take it apart again and inspect as I put the older impeller back in as I ripped the new one putting it back in. The older one only had 2 hours on it though. I think the key way may have been bent would that cause a problem? I took the boat 20 miles off Daytona beach on saturday and with the smaller prop 13.25x 17, and it runs like a champ. This engine has a 30 inch xxl shaft. Encountered some 4 foot seas and powered through them like they were nothing. the only problem is the 21 foot Proline center console is a little wet if the wind is blowing the spray back in.

 

[The Marine Doctor]

Re: Is 195 degree's or so too hot? 2.5 liter

Provided the impeller fit tight on the shaft it should work fine.<br /><br />TMD

 

[jdkzrt]

Re: Is 195 degree's or so too hot? 2.5 liter

Sounds like you have a midrange lean out happening with your carbs.<br />You can do a plug check to confirm, but you need to shut down while running @3000k (in the water).<br />This will tell ya exactly what's going on.

 

[shelbydriver]

Re: Is 195 degree's or so too hot? 2.5 liter

what should I look for on the plugs? A dry look?

 

[BRIAN03]

Re: Is 195 degree's or so too hot? 2.5 liter

?

 

[jim dozier]

Re: Is 195 degree's or so too hot? 2.5 liter

Back to BillP's comment about salt crystalizing at temps over 140. Bill that sounds odd to me as the solubility of NaCl, MgCl, Na2SO4, and MgSO4 and most salts except carbonates increase with temp. Most of the salting up of cooling passages occurrs during cool down when residual salt water evaporates in the channels if it isn't flushed out and ultimately causes corrosion of the Aluminum into Aluminum oxides and Aluminum carbonates which are the real culprits as they are hard and relatively insoluble even in hot water. The salt deposits from the previous run will usually dissolve immediately during the next run.