Overheating - older Mercruiser

[gboat]

Looking at a older 78 Wellcraft for sale with a 351 mercruisers IO. Took for a spin and 2 issues, At half trottle, temp is normal, full trottle 15 minutes pegs out temp gauge.??? <br />Bigle pump wasn't working, looked at fuse - good - connections all corrodied, cleaned and worked, anything to keep them clean. <br />Also anything good or bad about that year boat or motor or what I should watch out for in buying this boat.<br />THX

 

[jam1]

Re: Overheating - older Mercruiser

Use contact grease to keep the contacts clean and free from corrosion, can find at any auto parts store. As for the over heating, check the impeller in the lower drive that pulls the water in for the motor.

 

[Bondo]

Re: Overheating - older Mercruiser

The 351W Ford engine were not all that Popular during the Few Short Years Merc. used them.... Some Parts for it Might be a little hard to find.....<br />Running Any Boat at WOT for 15 Minutes is More than a little Hard on the engine.... In my area, you could be Shot for Abusing a Boat like that....<br />75% throttle is considered "Cruise" speeds..... WOT is for Only Short Bursts..... In my Opinion, the over-heating issue was more likely caused by the nut behind the wheel, Not the driveline....<br /><br />The Boat is older than most college students... It was a nice package in it's day,+ Still Could be.... It's a 351W Ford motor with a Mod.1 outdrive... If you want a Cruiser, Buy It.... If you want a Racer, Walk away.....

 

[magster65]

Re: Overheating - older Mercruiser

Yeah, not a good idea to run at wot for any length of time. I guess in theory it should do it but... why? It won't last at all. There's nothing wrong with Ford's 351 however it seems the manufacturers prefer the Chev 350. The heating problems could be a number of things and if it only does it at wot after 15 minutes there may be nothing wrong with it. A couple of degrees timing would easily do that. My in-laws have a 351 with over 2500 hours on it and it still runs well (they don't run at wot either ) bondo has good advice, if you want to run faster, shop for a different boat, there's lots to choose from that'll perform the way you want. Happy shopping.

 

[gboat]

Re: Overheating - older Mercruiser

Thanks for the advice, no I agree that you don't run them WOT, This is just what the guy selling the boat told me. I asked the same question as to why and he said he always ran his boats hard, Just another reason to walk away as Don't mind paying a price if a person has taken care of it. No now onto looking at a silverline - made out of Moorhead Mn, no closed and not associated with the current silverline boats., Any one know of any info on this. Its a 19ft,350 chev, seems to run good. Interior is really good. What do you know about these boats and would parts be hard to get, Also the Canvas bimini top is gone - where would a guy find one><br />THX