Was fishing the Cowlitz last weekend.Sucked up a couple rocks.No big deal.Raised the motor to make sure everything was kosher.Thats when we saw a shiny new bolt in the pump.Ran the kicker to get us back to the launch.Got home,pulled the impeller off and saw that 3 of the 4 bolts that hold the pump on had worked out and 2 of those were missing.
The long one in front was the only thing left holding the pump on.
Have another friend who's pump did the same thing this spring.His pump fell completely off though.
One motor was less than a year old the other barely over that.These were both 80 at the pump motors with factory stainless impellers.There was no lock tight or anything on the bolts.I heard rumors of one other doing this.
You might want to check your Mercs.Dont know if it affects just the 80s or others or those with stainless impellers or what.
Curious if any of you have had or heard of the same problem.If so I would appreciate hearing about it.

Hey Superfly . Is that why Thor Built puts them on there boats because they suck ?

Finally Superfly might be right about something.
Yamaha is the ONLY way to go.
However - NO MATTER what type of engine runs your sled, (assuming you have a pump on it) you NEED to check those bolts every now and then. Ideally when it is new (FACTORIES DO NOT DO THIS) back them out and use never-cease on them. Dont use lock tite, as you may actually WANT to take those bolts out to service the wear ring and or impeller. Never-Cease will stop the vibration from backing them out.
Also in Wrangell, AK where the boys do alot of backcountry jet boatin' - they take a peice of 1/4" nylon rope and tie that boot to the lower unit. THat way you CANT lose it. If you have to do a streamnside repair, or the bolts do back out, thats your safety line.
Hope this helps.

had the same thing happen to my 1998 mariner 80 jet. two bolts backed out, and one backed out until it hit the impeller. put it back together using aluminum bolt prep, no problems since.

If Merc's suck then so do Yamaha's,because Yamaha builds almost all Mercs Four strokes .

Even so the Merc Jet is a two sroke was does that have to do with a Pump falling apart ? Outboard Jets builds all the jets for everyone . Merc ,Honda , Yamaha and you name it , they build it for them .

How come all the big name guides run Mercs ?

If you compare Mercs to Yamahas dollar for dollar they are not less expensive . What does that say for the other brands ? Does that make them cheap as well ?

Never seize is not good on S.S. bolts and aluminum housing, causes electrolis problems and will seize the bolt into the housing. Yamaha only makes the lower hp motors. But then again Tohatsu builds the power heads for yamaha.

Yamaha builds the 40 through the new 225's and eveything in between in the four stroke .

Reiter, were did you get your info? Tohatso builds the small 4 strokes for both Yamaha and merc, Yamaha does not build any 2 strokes for Merc.

The pump (the bolts backing out specifically) falling off, has nothing to do with what kind of engine its mounted on, like RR says. THe pumps are all the same.
Its just an extremely harsh environment, lots of vibration and force from the h2o.
As far as the never seize and electrolysis, all the pumps I have owned have had sacrificial zinc anodes on them. I guess thats why I have never experienced THAT problem. The dissimilar metals still require some sort of lube/never seize to avoid inevitable corrosion.
I have had about everything else happen that could.
As far as manufacturers of the engines, it changes yearly. Just like in the auto industry (another industry I know just about nothing about), most manufacturers have their hands in everyone elses pockets in one way or another.
You ahve to look at their quality control programs for their finished products. Yamahas is ranked #1 in the industry according to several different surveys. (A couple different mags I read). That could change year to year.
I think that in this day and age, with proper maintenece, any of the outboards should run great for many years. I just have an affliction for Yamahas. In Sitka, there are about 150 to 175 charter boats running the snot out of their engines day in and day out. They ALL run Yo-mamas.
has anyone ever listened to the noise put out by a Yamaha jet vs. a Merc? You need earplugs to run the Mercs. Not sure why, but they are WAY louder.
At any rate, thats my 2 cents.

RR, I know of a couple big name guides in Oregon who both run Merc's but say they would run Yamaha's in a heartbeat if they were comparably priced and if there were as many Yamaha shops/mechanics as there are Merc.
I've run both for years in Ak. and if money wasn't an issue, I wouldn't even consider a Merc.
Yamaha is easily the outboard of choice among the Ketchikan and Craig charter fleets.

I run a couple of mercs and one OMC, I personally like my omc even though it is a prop, my bud has a newer omc ficht with a pump and loves it, I had my 225 go completely under (boat sunk) and after blowing the water out it ran fine, did'nt cost me a dime to fix! but for the sake of topic I fish all over and every place I go down south (mostly) Yamaha is the choice some of the guys I also respect in the biz say the same, as for me a good motor with a good running record is as good as any , as far me me a check, tighen , lube , flush, my motors every year.

i posted above about aluminum bolt prep, its not the standard never sieze. do not use never seize on aluminum, or you will unscrew you aluminum threads. aluminum bolt prep is made for the dissimular metal problem. any marine dealer has the stuff. its applied just like never sieze.

TroutMaster,

Hey your info is incorrect. Yamaha and Merc build the 9.9, 15, 25, 75, 90, and 115 together. The jets are built by San Leandro Outboard Jets. If they fall off I would be questioning the dealer who installed the equipment. As far as putting the stainless impellars on 115's I would call wooldridge or stevens and ask about performance results with those motors. I think you'd be suprised how bad they faired.

Onstep,

If it is factory jetted, such as a "65 jet or 80 jet", what does it matter if it is installed by Olympic boats or Stevens marine? If it is factory jetted should you not direct those questions to the manufacture?

I disagree it does make a differance what is is bolted to! There is a lot of considerations as to thread fit, bolt hole alighnment, alloy of the aluminum ,quality of bolts.balance of the impellor, and of course fit up of the mateing halves. these issues need to be addressed to be assured that the problem is solved .Just some ideas to think about.Hope it leads you in the right direction. good luck

They have been falling off for years!!!! Check your bolts every once in a while. Its a vibration thing. I have seen more than 3 fall off. Have friends had to be Heli rescued is S.E. Alaska becuase of same.

Oh Well!

Onstep, dig deep into your brain and you will find that Tohatsu manufactures the small 4 strokes for both. And yes we all know that outboard jet makes the pumps. Oh I forgot that you have over 20 years in the boat buisness like I do. Get your facts straight.