Expected problems with motor being run "dry"?

[ogeecheeflyer83]

A friend of mine (yes, it really was a friend and Im not just trying to cover my goof) recently ran his 1998 115 Johnson V4 at idle for 20 min to charge the boat battery with no water muff hooked up. Next trip to the lake the water pump wasn't moving much water and the engine was overheating. I helped him replace the water pump recently. The pump housing had melted and this is when I learned what had happened. Just wanted to know what other damage can be expected in this situation and how to check for it. I suggested checking compression to check for ring damage etc. Any other suggestions?
Thanks.

 

[Barnacle_Bill]

Re: Expected problems with motor being run "dry"?

Good idea to do a compression check. If that checks good he should be good to go.

 

[metriccrescentwrench]

Re: Expected problems with motor being run "dry"?

recently ran his 1998 115 Johnson V4 at idle for 20 min to charge the boat battery with no water muff hooked up.

WOW. I can't think of any other words, just WOW.

Suggest that he invest in a battery charger, it would be much cheaper than engine repairs.

 

[F_R]

Re: Expected problems with motor being run "dry"?

Probably scored the piston skirts, and cooked the head gasket and exhaust gaskets.

 

[mikesea]

Re: Expected problems with motor being run "dry"?

do a spark and comp .test ,check all wiring that is in contact to the block,pull thermosdtats and the plastic /rubber parts(I just got in from fishin ,my mind escapes the names)in the thermostat area .then pray

 

[Beek14]

Re: Expected problems with motor being run "dry"?

You can do major damages to an outboard being out of water for 20 seconds, let alone 20 minutes. I'm quite honestly surprised it still runs.

 

[rlb9844]

Re: Expected problems with motor being run "dry"?

My mechanic told me of a guy running his dry. He said that the impeller shredded. He had a time getting all the little peices of rubber out of all the ports.

 

[ogeecheeflyer83]

Re: Expected problems with motor being run "dry"?

Thanks for the replies. He got a shop to do a compression check today which was fine. (I am surprised) 120 on one cylinder and 115 on the other three. With a spark test do you just mean check the spark plugs and then ground them to the block while cranking to make sure they are still firing? Yeah, the impeller looked rough and on the verge of shredding. Will definitely help check the rubber/plastic parts and wiring. I have a personal interest in this boat and want it to run fine since it is my ticket for skiing My 14ft aluminum with 9.9hp just doesn't do the trick.

 

[Faztbullet]

Re: Expected problems with motor being run "dry"?

The t-stat housing are likely melted (good luck getting that goo out of head),temp switchs on head likely bad,rectifier will follow shortly. He should have heard the overheat buzzer buzzer unless it defective also.