90 Force water problem

[93nitro]

Hello all. Here's my story.... Just bought a 93 Nitro with a 90force on it. Was told the motor had low compression. (Diagnosed by Bass Pro Shop) Got the boat home and started looking the motor over and it appears really clean and like it had low usage. Upon further tinkering realized that it just has a bad starter! Bad call by the bass pros. Anyway, now that I have it running I hooked it to the muffs and turned water on about half way and fired the motor up. It ran for about 5 minutes and the overheat alarm started sounding. I didn't notice any water flow exiting the motor anywhere. I believe it is supposed to exit the 2 holes below the rear of the motor cover. Can someone please enlighten me on the inners of the cooling system? I can't wait to get this thing on the lake but don't want to blow it up either. Already planned on a new impeller as I'm sure its due for that anyway..... Thanks for the help on this awesome web site!!! Sean

 

[Justinde]

Re: 90 Force water problem

Hi Nitro

Welcome to the site. Water should exit the two holes@ the rear of the leg. The waterpump is an easy fix. I would take it out and inspect first. Even post the pics, but a new waterpump complete is $55.00 new on ebay. I am sure that it would suit your engine. Once your waterpump is sorted, I would still do a compression test, and check the spark, and even do an oil change in the gearbox. From there, start her up again and post the results. I would imagine that the waterpump/impellor are to blame, but by replacing it/them, you will eliminate that part of the cooling system problem. My 125 was overheating, and I replaced the waterpump, but also I removed the exhaust plate and it was full of calcified crap and sand. Start with your waterpump and get back to us.

Cheers

 

[NYBo]

Re: 90 Force water problem

Welcome to iboats!

Start with the impeller. Once you have the water pump apart you can evaluate the entire assembly's condition. You should get a service manual for the motor. A factory manual is best, followed by Clymer, with Seloc being the least desirable. Here is a great thread on impeller replacement. Don't forget to check the thermostat too.

 

[93nitro]

Re: 90 Force water problem

I tried attaching pic. Hope this works......file:///C:/Documents%20and%20Settings/User/My%20Documents/My%20Pictures/3-30-11/3-30-11%20001.jpg

 

[93nitro]

Re: 90 Force water problem

Don't think the pic is working but the impeller is close to being a round stub. I am SURE it needs at least this much. All of the veins are broken off of it. Was wondering where would the veins go when they break off? The housing the impeller rides in looks great so won't need it. The stainless plate it rides on looks good as well. Heck, even the gasket is still good. Super easy disassembly but spaced off the shifting lever hookup so had to backtrack a little. This site is sure helpful. Thanks all for the help! I REALLY APPRECIATE IT!!!

 

[93nitro]

Re: 90 Force water problem

Bought a new impeller, SS plate, and 2 gasket set for it. It's now on the way... I was also wondering if there is supposed to be some sort of seal on the lower unit when re-installed onto the upper unit. Did notice a LOT of white milky looking water on the garage floor before I began tearing it apart. Sorry if I sound like a dummy but this is my first venture into impellers, (or taking lower units apart) so thought I'd better ask the pro's! Thanks again, Sean