'96 88 SPL Overheat Problem

[steelhead18]

I was getting the boat ready today to take on vacation. While going over the motor (which runs like a top) the overheat alarm went off about 3-5 minutes at idle with the mufflers on. I'm getting a good stream (always have)but the block got hot so I shut it down. I let it cool off and tried again - same results, good flow but the block got hot. The water coming out was cool then real warm then cool again but block was hot.<br />Any ideas?

 

[Bob_VT]

Re: '96 88 SPL Overheat Problem

When was the last time the impellar was changed? The tell tale only lets you know the pump is working but not how much volume you are pumping. A second thought would be the thermostats not opening or sticking.<br /><br />Bob

 

[steelhead18]

Re: '96 88 SPL Overheat Problem

Bob,<br />I havn't touched anything related to the cooling system yet. No need to up until now. Always fresh water flushed after every use. Do I need to get a manual to replace the impeller and stats or is it as easy as just dropping the lower unit and there they are?<br />Thanks for responding

 

[Down South]

Re: '96 88 SPL Overheat Problem

Hello Steelhead,<br /><br />I have the exact motor that you have. I'm pretty sure you would want a manual for this job. You need one anyway. The manual gives detailed instructions on changing the water pump plus a wealth of other information on your motor. This way there is no guess work involved. Trust me, if you try this without the manual you'll probably be back here asking a lot more questions.<br /><br />Now back to the high temp problem. You may have a stuck thermostat which is somewhat of a common problem on this particular motor. I would replace them too.<br /><br />Below is a link that has a manual for your motor.<br /><br />Good luck<br /><br /> http://www.boatdealers.com/mall/ind...4688&current_category=johnson outboard manual

 

[DJ]

Re: '96 88 SPL Overheat Problem

Steelhead18,<br /><br />You will need to drop the L/U to change the pump. It's is not hard, just a bit tedious getting the shift shaft screw loose and back in.<br /><br />The stats. are a different story. They are located at the bottom of the powerhead between the two banks of cylinders. You will see two large hoses going to the stat. housing from the heads.<br /><br />To get this housing off, I have found it necessary to drop the lower cowl as much as possible by loosening all the bolts. You will also need to remove the wrap around plastic piece that is just below the lower cowl on the exhaust housing (mid section).<br /><br />This job is very tedious but it can be done without removing the powerhead.

 

[steelhead18]

Re: '96 88 SPL Overheat Problem

Thanks for the help guys.<br />I replaced the impeller (which didn't look bad but since I was in there I replaced it anyway)<br />The stats were slightly corroded and I replaced those too. I fired it up when I was done and it runs great. I've got warm water discharging at the cavitation plate and cool water coming out at the outlet hole. No alarm. Thanks again<br />This web site is very helpful. I only found it a few days ago. Coincidentally it looks like it was designed by the same company that designed Thumpertalk a site for 4 stroke dirt bikes. The layouts are identical