Yamaha 115 hp Jet Drive

[Soul Harvest]

The engine temp and/or low oil warning alarm began sounding on my 1997 Yamaha jet yesterday. It started while the engine was at low idle and after I had beached the boat on a shallow sandy/silty bottom. The engine was still "peeing" although the water was hot to the touch and I think the volume is less that prior to the alarm warning. After letting it cool for an hour or so, I started it again, the alarm did not sound, and the water coming from the engine was cool, volume was still down. I ran the motor for about 10 minutes at speed and the alarm did not sound. Later in the day I pulled anchor and had the engine idling and the alarm sounded again.

I am thinking 1) possible blockage on the water pump intake, 2) faulty water pump and 3) possible oil problems (although all oil reservoirs are full). Any suggestions?

Also, anyone have suggestions of finding a manual that will help me pull things apart on my own, rather than a shop. Or am I talking a repair that does not lend itself to the average to better home mechanic?

[budnate]

you probably packed the motor with silt, seen it a few times, hook a garden hose to your flusher and gentley run a bunch of water through it and unhook the flusher to it then let it drain out completely then do it again a bunch of times not running, then fire it on the flusher and let it idle sometimes the added pressure and the stats cycling will get it out of there, keep touching the heads with your hand if you cant hold your hand on them longer than a few seconds your to warm, if there warm and you can stay on for like 20 sec or so your fine.

I have a 115 omc that took over a year of flushing and running to finally clear some spot in the power head, drove me nuts, that fine silt will pack well.

peace, B.

[Soul Harvest]

Thanks budnut for the response. I will give it a try and see what happens.

Anybody have ideas on manuals for this motor? Yamaha motors indicates they are out of stock. E-bay has them, but I was not wanting to go to that trouble and time to get it shipped. Anyone know of a source in the Portland Metro area?

[hookanook]

Originally Posted by Soul Harvest

Thanks budnut for the response. I will give it a try and see what happens.

Anybody have ideas on manuals for this motor? Yamaha motors indicates they are out of stock. E-bay has them, but I was not wanting to go to that trouble and time to get it shipped. Anyone know of a source in the Portland Metro area?

[hookanook]

I have experienced the same problem with my 1991 Yamaha jet. You can probably flush out the silt without replacing the pump. You may want to replace the water pump anyway because at some time you will need to. The problem I found was after years of saltwater use, the stainless steel bolts became seized in the aluminum housing. The bolts all broke on dissassembly and had to be drilled and retapped. It would have been easier to just replace the entire pump unit. You can avoid this problem by replacing the water pump earlier before the bolts get totally corroded.

[Lead Bouncer]

When is the last time your water pump was changed?

[hookanook]

I have a manual for this motor. E-Mail me at Hookanook@MSN.com.

[Soul Harvest]

Originally Posted by Lead Bouncer

When is the last time your water pump was changed?

I don't believe it has ever been replaced. I had annual maintenance for the the duration of the warranty, and have done every couple of years since. I did not have a problem and I don't recall ever paying for a waterpump.

I did connect the hose to the unit, ran it at high pressure w/o the motor running shutting the water off several times. Then I turned on the motor and ran it at low idle for at least 15 minutes. It was shooting a pretty good stream of cold water for the duration. The heads got warm, but not to the point of burning my hand. Looks like I may have sucked up mud or sand and that was partially clogging the inlet.

Because this doesn't really feel like a full solution, I am probably going to put in a new water pump, and possibly check my spacing on the impeller. Sounds like good maintenace at 11 years. I also have a manual and I think I can follow the info sufficiently to do the job. I would appreciate any suggestions, insites, and experiences that would help me avoid and expensive trip to the "doctor" cause I put it together backwards!!

Also, thanks to those of you who finally responded. The input was valuable and confirming my diagnosis.

[jig4herring]

I had this happen on my 50 hp johnson, and the water pump was shot. Turned out the guy i bought it from started it up out of water. water pump fixed it. my motor is 30+ yrs old.

Good luck