yet another 15hp question

[johnyrude200]

I have the motor apart and both inlet and exhaust water tubes appear OK with a solid 1/4 inch diameter hole, and looking closely I don’t see that hole getting any narrower within 1" of the opening. I’m looking over the rest of the motor now with exhaust bypass, cylinder, etc. 2 broken screws I have to drill out and retap. Yippee. Then onto further inspection.

[johnyrude200]

Well guys, I don’t want to get ahead of myself, but I may need to officially declare myself a moron. After completely disassembling all water passages, scaling off old gasket, replacing all exhaust and bypass gaskets, I decided to take a break for lunch. Right before I head in for some grubb, I took a quick gander at the water inlets on the gearcase. I would say they are about 85% clogged with stuff.

I’ll be putting everything back together after some chow and getting the motor back running. After pulling everything apart I started suspecting something in the gearcase, and I have to say this is a big clue in the right direction. Will confirm if this is the issue.

If it is (which is probably is), I think I’m going to be putting together a checklist for water clog issues to avoid wasting 6 hours for needless ‘ghost chasing’ moving forward.

Ugh.

😳 😕

[johnyrude200]

Well, I can confirm the issue. Apparently my test tank is so full of old bits of leaves, pine needles, sand, etc, that it is clogging up the intake on the motor. Looks like I’ll be adding some new water in.

Sorry for the hassle, but this has been certainly educational!

[fleetwin]

Well, am surely sorry to have helped you "jump the gun", but these things happen to all of us. In any event, you may want to trim those grommets down some while you have it apart.

[johnyrude200]

I took your advice and trimmed them. And my miscalculation had nothing to do with you! I appreciate all the help. At some point I’ll run into the grommet issue so at least I’ll know what to look for right away moving forward. I have another 3 of these motors I have to get done in the next 3 weeks. Just another learning lesson I guess.

[dan-in-tn]

The pics are very helpful, especially since I sent my manuals to you and don’t have anything to look at anymore. Don, Cajun, JohnnyRude, I thought the flow chart showed the water turn red after it turned into warm water. Is it just the copying that took that away?That always came in handy when you were trying to explain it was just as important for water to get out of the motor as in to prevent an overheat.

Dan in TN

[dan-in-tn]

Wonder what water pressure gauges would do on small motors? Anyone ever try one? On the big bass boats almost everyone has one. When they get into weed, sand, crap, the pressure goes down and they know to back up or clean their pickups. Never thought about using one on a small engine, but might be another tool that could prove the water volume is going away. Just an idea off the top of my head!

Dan in TN

[johnyrude200]

That’s a good idea Dan. I’ve been researching inexpensive options for a temperature sensor for the older motors. I’ve found some on eBay which are pretty low cost (like $5), my only hang up is how to attach it to a cylinder. I was thinking of just using some silicone and gluing it on, since silicone is good up to 600°. I can then run the wire out of the pan and onto something I can see while underway; now just to figure out if the LCD gauge can handle exposure to the elements!

Sure would be helpful in avoiding overheat/seize conditions.

[chris-p]

I have an ’85 15hp I have to open up soon as its seized. Was hoping I could free her up with traditional methods, but peeked in the ports and see a very rusty connecting rod! These diagrams will come in handy as I can tackle the grommets at the same time!

[johnyrude200]

Well sit tight. I have a little surprise for everyone to benefit from for free in the next few months.

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