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1985 3 cylinder 90 hp Yamaha, 8 hp Honda BP8 1990.

She's been running like a champ. Yesterday while on plane and cruising at 4300 RPM the big motor stalled suddenly and came to a complete stop. Upon trying to get it going again I checked the primer bulb, it seemed firm. No overheat alarm, the plug wires were securely attached, plenty of fuel, etc. I ended up getting home on the kicker which runs with gas out of the same tank (28 gallon Tempo). I leave it at the Marina overnight.

When I went to get the boat this morning, the kicker fired right up and idled for 2 minutes then died and I couldn't get it restarted, so I roped it around the dock system to the sling and got it home. When I put it on the muffs, the 90 hp started right up with extra throttle (1500 RPM). It ran great as long as I was giving it gas, but then would not idle.

I went to start up the kicker and it fired right away ran for 2 minutes and then died, wouldn't restart. It has been acting very erratic for a while though and I can't figure out if they are related or not. I immediately think water in the gas. I siphon fuel from the bottom of the tank into a glass jar and no water. I check the fuel filter bowl on the big motor and no water. So then I think fuel flow problem.

Both engines are fed with one big tank and there is a valve I use to select which motor. I think maybe something is wrong with the valve so I drop the fuel line leading from the primer bulb directly into the tank and same thing, run's fine with extra gas, won't idle. Can anyone help, I'm losing my mind! Thanks!

D

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Sounds like you forgot to open the vent on the gas cap.

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I iwish.

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Contaminated Fuel? do you have a water separator? if so are you using a 10 micron filter to help with ethanol?

Try draining the carbs. The 90 yamie has brass nut om the bottom of each carb on the left as you look at the carbs. You do not need to completely remove them just let them drain. You do not want to drop them in the lower cowl...

good luck

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Sounds like you have a fuel delivery problem if both engines are doing it.

If only one engine was doing it from the same tank, then I would say something is wrong with one engine. But it doesn't appear that way.

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It does sound like fuel so I would look for sediment in the fuel tank, if necessary flush the tank, fill with fresh fuel and replace the fuel filters all very easy. Next, if I still had a problem I would pull off and the clean the carbs. One other possibility is that your 20 -25 year old fuel hose is degraded and falling apart either by age or by ethanol so it might be wise to replace that also.

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Disconnecting from the existing tank and running of a different one is one step. The next item to eliminate is the fuel line and primer bulb.

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Okay, thanks all for the input. My tank and fuel lines including primer bulbs are new within the last 6 months.

I'm going to try replacing the fuel and then think carbs. I'll keep you updated! Thanks.

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Also, run some Sea Foam through your carbs after you put new fuel in your tanks. Sea Foam works great at cleaning out the carbs.

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Stail fuel maybe?
Sounds related
Good luck

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Not fuel... Took it to a mechanic... Scored cylinder and zero compression... Ouch. My first boat, first Whaler, first engine melt down.

I had trouble with it since the first day I got it with near constant over heating. One thing after another now she's dead in the water. There is a 1995 Yamaha 90hp on Craigslist for $2600. Supposedly in good shape. At this point I'd like to re-power it and sell it. Not sure what I should do. Do people buy these motors after they go TU? Thanks in advance.

Any suggestions?

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Both engines have zero compression?

If only one engine, why doesn't the other one run properly?

If you sell, are you going to buy another boat?
If so, you might be buying someone else's problems again.

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No, the little motor is fine, it was a fuel flow issue as we suspected.

I really don't want to sell it but after the re-power investment, the finances may force me to. Not cool.

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That's good to know about the smaller motor.

I understand that money is tight these days.
If you had a mechanic check out that other engine for $2,600 dollars, that might not be a bad way to go... Hopefully a freshwater engine.
Or keep looking for a good used freshwater engine.
Sometimes dealers get good trade-ins.... and then they might give a short warranty.
Good Luck

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Thanks Joe, I appreciate your advice.

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I blew a hole in the #3 cylinder of the 85hp commercial version of the same motor so I know your pain. The the 90 has oil injection but mine was premix. Actually I overheated it one day and warped the head a little allowing a small amount of water in the cylinder. A new head gasket didn't fix it and I ran it for another year before I blew it. That motor saw a ton of fish though. I used to run it 20 miles offshore VA Beach or 30 miles one way up the Ches Bay without a second thought.

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Sorry to hear the news.

I was under the impression the motor was running like a champ (post 1).

If you had mentioned the overheating, I would have skipped the advice on fuel and pointed you toward a mech

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Not to make a joke of this but don't they all seem to run like a champ just before they crap out?

I don't know how expensive a rebuild of the top end might be but it is one option to look in to depending upon the condition of the rest of the motor. If you do scrap the blown motor then keep in mind the lower unit has some good value to those searching and could off set the costs a bit. You can be sure the shop that ends up with it will be looking to get it free and to sell the lower end for close to $500 and the PT&T if it has it for another good chunk. Part out what is still good.

Gary

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Re-building the head on a 1985 motor seems useless to me. Sorry about your troubles dmrose. My brother had issues with his 1994 Johnson 115. Spent 3 thousand on it last summer and it started acting up again. He chose to re-power.

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Good point JF and you can't do it at $100+/hr in a shop but a DIY top end rebuild is doable for some of us with friends and some mechanical abilities. At $3,000 I too would go for a brand new one and pay the bills. Buying a used other guys headache is not my idea of good finances unless the other guy is rich and just plain dumb.

My motor is an '84 EV 90 and if it does not run for pretty cheap then my next one will be a 2010-2011 and I'll be asking for forgiveness because it is easier then getting permission.

Gary

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My brother has money. He bought a Mercury Optimax 135 of the same year with only 400 hours on it. They charged him 2 thousand dollars for rigging, new gauges and oil tank. Something that could be done in a days time. I would have done it for him but we go to Lake Placid, Fl every year for a week in the summer and he doesn't have time to waste.

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My brother also John and what is even worse is he thinks the shop that hoses him the hardest is the best because they get the big bucks for all their repairs. His last repair was in the shop 3 times to finally get it fixed and what finally did fix the issue had absolutely nothing to do with the $900 in parts and labor they had already done. Parts changers.

Gary

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D, most unfortunate... I have a Yamie 90 as well and it has been a very solid runner... Like any other engine it will die eventually... Today, if I to make a decision to do a a rebuild I would look at at other options. New (older model if possible) if I can spend the money... Used from a dealer with a warranty of some kind, or an engine you know from a friend.

I would stay away from anything on ebay or online that says it has been professionally rebuilt... You would never know if it has been done according to specs and by someone who is really qualified.

To spend $1500 or more on a 25 year old engine does not make good sense to me... Unless you can find a a good power head to swap with and the total cost is below 1500...

If you part this out... The power trim if it works can sell for $250, Lower unit $350, misc parts $300 or more... another 50 for the cowl...

my 2 cents

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My guess is that your fuel flow problem starved a single cylinder and caused the damage. I don't know if you are aware that on these triples, it's entirely possible to bore just the single cylinder that failed, and install an oversized piston - there's no need to have a full rebuild done.

If your mechanic does not know that, you may wish to consider finding another mechanic. Check out the compression in the other cylinders, and if they're OK you may be able get away reasonably cheaply. Oh, and don't forget to have the fuel problem taken care of or it'll happen again:-).

However, I do agree with the previous post that you've got to be careful how much you invest in an older motor.

Tim

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Given the cost of a repower with new, (7-10K), or the potential headache of someone elses' used motor that you don't know, the prospect of spending 2-3K to repair what you have and know is not all that scary to me.

My current motor ('90 'rude 88 SPL) is now 21 years old with about 150 hours on a good rebuild. When it let's go I don't know what I will do. It burns a good amount of fuel and limits my range, but it is also one of the longest lasting motors ever made by all accounts. If it dies, I can do a power head myself for about 2000-2500.

I currently have a 1999 FICHT 90 with a bad rod and scored crankshaft in the garage. A rebuilt power head off the internet is 2200-2900 if I do the swap myself, with no warranty. Here in the bay area, most shops are quoting close to 4K to do the work, and they are not jumping over themselves to get the job. I worry about even doing this one since the cause of the failure has never been pinpointed.

I am a service rep, and do most of my own work. For the most part I do not trust many mechanics fom too many bad experiences. If I need repairs I try to them myself as I have the most invested personally.

I want to repower, but the investment to do so is very hard to justify it, since it will never be recouped. Mileage and fuel burn rates are gonna take a lot of hours to offset that cost.

If what I read about the yammi 90's is true, they are very good motors. It sounds like the failure was fuel delivery from the tank to the motor, which to me is another factor to consider. I think I would examine the rebore/oversize psiton route and make sure my Seatow membership is paid up.

just a thought.

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Thanks all for the input. According to the mechanic he suggested that the motor was salted up pretty bad (i flushed it every time without fail) when he removed the head. He proposed that a rebuild wouldn't be worth it in the long run.

I'm seriously thinking of buying this used 1995 90hp that showed up on Craigslist on the day she blew up.

The owner purchased it from someone who repowered with a 4 stroke. It used to ride on a Whaler. We are considering meeting at Bayside Marine in Everett to have it looked over by a mechanic. Baring a passing grade I would just bring the boat there and have it installed professionally. Hopefully I can have some security by paying a shop to take a look at it. If I was confident it was a good choice I would run it for the summer then look to sell the boat.

@ Phil, It had overheating problems when I first bought it, but with repeated use in fresh water, a new thermostat, sensor, and a new impeller the issue went away. I haven't had the alarm go off in over a year. It WAS running great, then kapow....