the perils of evilbay!!! another engine needed

[ericcs]

85447
85448
pistons 1(10psi) and 2(still 120psi)at from my 2003 yamaha 90 2st(both bores are heavily scoured)
i bought the engine about 3 months ago, but have have only used it twice. it was advertized for 4.5k, amd looked as new. ended up giving my yamaha 70 2st plus 2.5k.
this is what happened after 3hrs run time, so the privelege cost me 1.5k/hr.
cruising across moreton bay last sunday, the motor started to slow down to an idle, then take off again. the symptoms suggested a fuel blockage as it never missfired, made no unusual noises and was pumping heaps of water. did this several times bunny hopping back to wello, eventually stopping dead in the middle of nowhere. took off the cowling, everything looked normal, powerhead heat felt normal. i tried to restart it, it made horrible noises so i shut it down and got towed in
it appears the warning buzzer, light in the tacho or the limp home mode don't work either. my theory is the oil pump failed, but can't check it unless the engines running i guess. it was running fine and the fuel is only a couple of weeks old, so can't think what else it could be.
so now i need another engine, and will need to take the punt on another second one, as the yamaha will probably cost 4k minimum to repair, so will probably part it out.
is anyone out there selling a reliable post 2000 long shaft 90hp?:(:(:(

[MudRiverDan]

Looks like they are the wrong size, pistons expand with heat.
Common problem with buying of EBay, needle in a haystack to match your pistons reliably down to a thou.

I know nothin of boats but have seen this in Commie engines with online pistons many times.

If you bought the whole engine, maybe a patch up and sell job, very shonky.

Dan

[cormorant]

Hmmm I wonder if the alarm circuit has been fiddled or just failed? Is there a special way to bleed out a yammi oil system when installing? What a expensive disappointment. Import a powerhead for it?

[Feral]

Ah the perils of second hand boat engines.
I reckon everyone my father ever bought (and its been quite a few) was more suitable as an anchor than a propulsion unit.

Always told myself I would only ever buy new.

[TREVELLY]

Sorry to read about mate - that's terrible - makes my little stone arriving instead of fishing reel on ebay seem like nothing.

Probably too long a shot to have it disputed as not as described and not fit for purpose item (ie working motor) - you could investigate small claims tribunal for being sold a dud motor but then you have the hassle of proving it was their fault and not yours - another pain.

Buying new is far superior but at a cost too and even then with greatly reduced risks still they exist ie 140hp Suzuki put on back of Roscoe's glass cat, but atleast it was sent back for replacement after a fight and getting the bank to stop payment.

Best bet if possible is to test run the motor for some hours before parting with the money - ie pay a deposit and agreement to pay in full if the thing works after three or fours hours running on the back of your boat - taking the seller along for the test run, so they can row the boat if it fails!

[bf90]

I used to have a 70 johnno 2 banger, it did the same thing as your yam, my problem was caused by a partial blockage in 2 of the carbys thus not allowing the correct oil/fuel mixture in and my pistons looked exactly the same as yours. All the motors are mate is a bloody big lawn mower donk :) strip it down ya self, get the block bored out and go get some new genuine goodies to put the motor back into service again . I did this with my johnno from memory it was about $700 in parts and the block boring, all else was just my time. I changed my motoer from oil injection to pre mix and never looked back again. Cheers.

[ozscott]

Sorry to hear that mate. More broadly I have had several fantastic second hand motors but always inspected and tested first or dealer sold. Cheers

[mustang5]

Sounds like she went short on Fuel as you described. No fuel = no lubrication.

Same thing happened to my Yam 200hp a few years back. Check the top of the piston on the outer perimeter. If it looks all banged up, fuel shortage/detonation is the cause, due to a blocked carb.

Given the age and hours of the motor, Im not sure you can put it down to a dud sale unless it is proven otherwise.. Question to ask is what sort of filter setup do you have running to the motors? When was it last serviced?

[Bros]

It doesn't matter weather it is Evil bay or just a second hand motor from a dealer it is all the same. Many years ago I sold a boat with a 40 hp black anchor to a bloke I knew but didn't see regularly. I saw him about a year after I sold it to him and asked how it was going. He said after 3 mths it blew a hole in the piston and I believed I sold it in perfect condition.

[ericcs]

mud river dan - could very well have been a patch up job, as the bloke had a dozen different motors in different states of repair. the picture of no.3 piston has it looking very new, you would think there would've been some light wear marks85456

corrmorant - it would be handy to know of a way of staticly checking the oil pump. i'll check the price of a new powerhead, but the potential cost of a new oil pump and the fix or replacement of the alarm circuit may be just too expensive

trevally - the fellow i bought it off wasn't concerned whether i bought it or not and said i could bale out of the deal if i had any concerns, so i took it he wasn't trying to sell a dud asap, and being a clean 2003 with a good reputation i thought i was pretty safe, and it had 120psi in each pot. unfortunately i didn't get to use the boat properly for about 3 months, so i can't prove i didn't cause the problem. i would dearly love a new engine, but thats beyond reach now, so it will be another risk again

bf90/mustang5 - you both could be right on the fuel theory, as it wouldn't rev past 5200rpm spinning a 15'k prop on a 5m quinnie. it was pumping oil initially as the tank was full at the start of it's first voyage, but don't know if it used oil on it's second fatefull voyage. it was never revving much above 4000rpm on the day

[ericcs]

It doesn't matter weather it is Evil bay or just a second hand motor from a dealer it is all the same. Many years ago I sold a boat with a 40 hp black anchor to a bloke I knew but didn't see regularly. I saw him about a year after I sold it to him and asked how it was going. He said after 3 mths it blew a hole in the piston and I believed I sold it in perfect condition.

i understand where your coming from, as i will have to buy second again and put my trust in someone who may not offer any warranty. unfortunately, as you would know, with ebay you more often than not commit you take the punt and buy sight unseen thanks to distance etc.

[Fed]

You'd think if was an oiling problem all 3 would be scored.

[cormorant]

Is the scoring the same all around the piston? What is it like on the inlet side compared to the exhaust? Measure the bore up closely as this may be the result of someone doing a repair already- do all the pistons look exactly the same- like original - same part numbers ?

[Spaniard_King]

Just about to trade in a 90 merc 170 hrs or there abouts... pm me if you are keen it's very tidy and genuine

2007 Imaculate

[ericcs]

You'd think if was an oiling problem all 3 would be scored.


on 2 strokes, an amount of unburn't oil drains to the bottom of the crankcase, which is normally sucked up under vacuum thru a hose and fed up to the top bearing to dribble down again. my theory was that the middle and bottom pistons survived a bit longer because off the extra bit of oil

[ericcs]

Is the scoring the same all around the piston? What is it like on the inlet side compared to the exhaust? Measure the bore up closely as this may be the result of someone doing a repair already- do all the pistons look exactly the same- like original - same part numbers ?


all i have done so fare is taken the plugs and exhaust cover off. i,m in 2 minds what to do, sell it assembled/complete or strip it down and part it out. all the plugs looked perfect and the same colour, a browny grey and dry! i also shone a torch down the plug holes, and all the crowns looked fine.

[Fed]

I'll go with your first theory Ericcs, fuel delivery problem, the bottom cylinder would be the last one to have a problem.

[MudRiverDan]

I'll go with your first theory Ericcs, fuel delivery problem, the bottom cylinder would be the last one to have a problem.

I know I am a bit ignorant here but if there was no fuel delivery then how did the engine keep going to the point of seizure?

Or would they just run leaner and leaner until the piston got too hot and seized?

Dan

[ericcs]

I'll go with your first theory Ericcs, fuel delivery problem, the bottom cylinder would be the last one to have a problem.

sounds very feasable, so asuming the carbies are ok. i guess a fuel preasure gauge would be needed to see if the fuel pump is working ok. i would still like to find out if the oil pump can be statically tested to eliminate it.
if it is only a fuel delivery issue, and the oil pump is still working, it would be safe to assume the crank and big end bearings should be still ok?

[Fed]

Sorry Dan I should have said reduced fuel delivery.
With partially blocked fuel vent, fuel pickup or fuel filter a motor will still run fine at lower RPM but when the revs are increased it will start running out of fuel because it can't supply enough flow to keep up.

I don't think it's a proposition to try and test the fuel system, fuel pump & oil pump on a non working motor ericcs.
What sort of fuel tank is in it?

Edit: I think you would have to count on every part inside the engine to be rooted ericcs.

[ericcs]

Sorry Dan I should have said reduced fuel delivery.
With partially blocked fuel vent, fuel pickup or fuel filter a motor will still run fine at lower RPM but when the revs are increased it will start running out of fuel because it can't supply enough flow to keep up.

I don't think it's a proposition to try and test the fuel system, fuel pump & oil pump on a non working motor ericcs.
What sort of fuel tank is in it?

Edit: I think you would have to count on every part inside the engine to be rooted ericcs.

fuel tank is underfloor with 2 vents(5m quintrex) whick aren't blocked as it pisses fuel out of them when i fill it up

[ovakil]

Take it apart then make a decision on what to do.My engine I got rebuilt after owning boat 18 months.Looked at buying 2nd but didn't want to risk it.Couldn't afford new,so I rebuilt it knowing that I would never get close to the money I paid.But I was keeping boat & I knew it would be reliable.

[ericcs]

will probably pull down atleast to try and find the problem, even if it's too damaged to repair

[Fed]

It might not be practical to do ericcs but maybe you could drain the fuel bowls and see how much comes out of each.

A couple of things I've learned over the years.

Test all the alarms.
Run premix in the first tank until oil usage from the injection is confirmed.
Go for a WOT run and make sure it's getting the right RPM, write it down.
Do a WOT run from time to time and if you ever see the slightest hint of a lower RPM then get it looked at straight away. (I give mine a short test every time I use it)

[ericcs]

It might not be practical to do ericcs but maybe you could drain the fuel bowls and see how much comes out of each.

A couple of things I've learned over the years.

Test all the alarms.
Run premix in the first tank until oil usage from the injection is confirmed.
Go for a WOT run and make sure it's getting the right RPM, write it down.
Do a WOT run from time to time and if you ever see the slightest hint of a lower RPM then get it looked at straight away. (I give mine a short test every time I use it)

g'day fed, your right with your pre purchase checks, would've been handy tho if the motor was still on a boat. one thing i did notice was on my first test run, it only revved out to 5200, spinning a 15k prop on an empty 5m quintrex. my old 70hp yam spun it's 17k prop to 5600 no problem. i planned to address the problem, but it didn't last long enough
i guess you need to have an intimate knowledge of the paticular motor to be able to do a safety circuit test, but in hing sight, it's worth the effort to study it before you commit
when it started to play up, they were classic running out out of oil symptoms, any thing other, i would have probably thrown in a bottle of oil as a precaution. oh well, next time
eric

[dnej]

Eric, how old is the fuel you are using?
David

[ericcs]

Eric, how old is the fuel you are using?
David

dave, the fuel was only a a couple of weeks old.
i learn't my lesson many years about stale fuel. this engine's spark plugs looked perfect, a light brown grey, and the piston crowns all look clean, unlike the skirts. eric

[Noelm]

on 2 strokes, an amount of unburn't oil drains to the bottom of the crankcase, which is normally sucked up under vacuum thru a hose and fed up to the top bearing to dribble down again. my theory was that the middle and bottom pistons survived a bit longer because off the extra bit of oil
you do NOT have an oil problem, do not get side tracked by that, you have either a lean burn or a dud "rebuilt" motor.

[Adam84]

My heart sank as I read this. I bought a 4m Pongrass on the weekend just so I could strip the 2yr old 40hp Suzuki outboard off the back of it for my 4.3 Quinnie. Although my new motor only has 20 hrs on it, and may be still under new motor warranty, I too potentially took the gamble of buying 'someone elses problem' off ebay.
Perhaps you could do what I have done and buy another boat with a decent/near new outboard on it? Then swap motors and sell the other boat with your blown motor? I paid around half the price of a new motor for a 4m boat, trailer and the motor, with gps chart plotter/sounder and new bits like bimini, gauges, winch etc all over it. And when I sell the other boat, it will subsidise the costs and make my 'new motor' even cheaper....
Just a thought but if you shop around you may too find a bargain saving a fair bit of money.

[ericcs]

you do NOT have an oil problem, do not get side tracked by that, you have either a lean burn or a dud "rebuilt" motor.

this makes sense as in the 3hrs of run time, it did use about a third of the oil in the tank. also, it's quite possible the safety circuit still works, as on my understanding, it only picks up either overheating or oil flow/oil level. i was able to comfortably put my hand on the powerhead without burning it off.
i'm curious to know, if indeed it was running lean, with the top piston being the worst followed by the middle and the bottom appearing to be not too bad, could it possibly be a fuel delivery issue, as opposed to blockages within the individual carbies?

[ericcs]

My heart sank as I read this. I bought a 4m Pongrass on the weekend just so I could strip the 2yr old 40hp Suzuki outboard off the back of it for my 4.3 Quinnie. Although my new motor only has 20 hrs on it, and may be still under new motor warranty, I too potentially took the gamble of buying 'someone elses problem' off ebay.
Perhaps you could do what I have done and buy another boat with a decent/near new outboard on it? Then swap motors and sell the other boat with your blown motor? I paid around half the price of a new motor for a 4m boat, trailer and the motor, with gps chart plotter/sounder and new bits like bimini, gauges, winch etc all over it. And when I sell the other boat, it will subsidise the costs and make my 'new motor' even cheaper....
Just a thought but if you shop around you may too find a bargain saving a fair bit of money.

i have done this in the past to brake even with motor upgrades, and thought about again for this boat, as an older boat/newer engine package like your purchase, is not neccessarily more expensive than an engine for sale on it's own. i have however secured a very good looking mercury 2007 90 2st from an ausfish member which i had no problem in agreeing to the purchase over the phone sight unseen. yes, there is always a risk, but i think he has good credibility even though i not met him. i have learn't on this forum, that the majority of members are a close knit bunch willing to help out a fellow boatie.
i have in the past had great purchases on ebay, and yes, been burn't more than once, but will definately be more diligent next time as these were 3rd degree burns for me financially. now i need to workout what to do with the yamaha to recoup some cash
eric

[WalrusLike]

this makes sense as in the 3hrs of run time, it did use about a third of the oil in the tank.

Does that seem a bit excessive to anyone else? How big is the oil tank?

[ericcs]

Does that seem a bit excessive to anyone else? How big is the oil tank?

it was only a very quick glance at the tank under the cowling, more to prove that it was pumping oil