302 merc overheating

[Sharps-Nut]

My brother has a 1973 merc 188hp 302 that has a overheating problem. It runs about 10 minutes from cold till the guage shows hot, 200 degrees or so. Is there a way to find out the condition of the water pump in the outdrive short of disassembly. It is getting water to the motor a leaky hose showed that much, but could it be to low of volume. Last which manual would you recommned, seems clymer and seloc, yea thats spelled wrong, are common. Any preference one over the other? Any advice appreciated.

 

[Bt Doctur]

Re: 302 merc overheating

2 years or more ,replace the impeller anyway to be sure. could be the impeller, water tube,connecting hose from drive to transom housing,manifolds,risers,therm housing, therm,circ pump,clogged block, head gasket.<br />Hot on a hose or hot in the water?

 

[Sharps-Nut]

Re: 302 merc overheating

Hot in the water. I hate to say this but he went to test drive this boat. They got it out in the middle of the lake and it got hot. They shut down. The guy offered to fix it and take the same price or come off a bit on the price and take it as is. My brother choose the second. Its a nice old boat and the dealer has a good reputation so I feel its little problem not a big one. I still would have still choosen the first option but he drove several hours to get it so he just finished the transaction.

 

[Hog Wild]

Re: 302 merc overheating

Either manual is fine. My choice is buy both they are so cheap compared to boat/fuel/repair bills. (I personally just own the Clymers for my boat). Gotta take that lower unit (outdrive) off and get to that pump and change that impeller then start thinking from there. Be careful getting the pump off and replacing it. If in doubt replace the WHOLE pump, housing, impeller and all, cheap insurance. Don't over think the situation, a pump missing a couple blades will still pump some water but not enough.

 

[Sharps-Nut]

Re: 302 merc overheating

Thanks hog wild started to think I had bad breath or or something like that. I found clymers for 26.00. I gave his boat a real good looking over last night. Man for a 1973 this old bugger is a slick one and solid as rock. If we get this over little overheating problem cured I think he did real good for 2300.00 bucks.

 

[Hog Wild]

Re: 302 merc overheating

"If?" Oh you'll get the overheating issue resolved. Many happy days boating! "too bad your not proud of where your "From:"..

 

[Sharps-Nut]

Re: 302 merc overheating

From the garden spot of the planet, beautiful south west missouri. Thanks for the atta boy.