I can't believe this happened

[ward cleaver]

Re: I can't believe this happened

How old is this motor?

 

[metalwizard]

Re: I can't believe this happened

Rebuild the carburetors or you may get to do this entire process over again. Lean fuel mixtures due to clogged/partially clogged passages are more to blame for engine failures than anything else. Most outboards don't wear out -- their owners and prior owners kill them.

I have to agree with this statement TOTALLY .

As for your engine.

I am not a boat mechanic so please understand my advice is GENERIC. I was a Chevy and Jeep heavy line tech for years so I have been through HUNDREDS of motors..

Looks like you have a couple problems. Heat being the first. The piston melted for one of a couple reason. most likely LEAN mixture. this could be a carb problem. or a vacuum leak. SO if you do rebuild the motor.. think about that. you dont want it happening again.

The main bearings.. looks like you may have SPUN on. OR just overheated it. hard to tell from the pics. I am going to say (just a good guess) lack of lubrication. this could be from several things. Possible HEAT from the lean running cyl. OR it could have been damaged from the piston sezing up. remember it didnt just seize in one rotation.. it went around a bunch of time causing more damage each time.

Here is my suggestion.

HAve the crank turned.. crank turning is not super expensive. you haveto get new bearings so a fresh crank journal will be your best bet.

Yes new pistons. I would say First oversize (use your mic. and check the bores.) you might need to go .030 over. not sure what is standard for that kind of motor.

once you do that. think about a new oil pump. remember that is the HEART of the motor.. oil is the lifeblood.

NOW don't listen to the neigh sayers.. even on the MOST complicated motors out there. rebuilding a bottom end is not all that tough. the hard part is usually getting to it, and getting it back in and together.

Last thing. check the surface of the head. if it was that hot, it probably is warpped. resurfacing is a possibility.

Last thing. you messed with the fuel (added additives.etc) DUMP it start fresh.

I hope this helps out. good luck.

Dont feel to bad bro, I bough my first boat last year. took it out once. ended up doing an intermediate housing. then had to do the motor (froze and cracked it) now i have water in my upper.. so I have had it out twice this season and it's still not 100%... but hey it has been fun and I learned alot. I know this boat inside and out.

Take you time ask lots of questions. you can do it. and when you are done you will have a feeling of pride yo never had before in your boat.. because you built it!!

 

[fishfeatures]

Re: I can't believe this happened

I have to agree with this statement TOTALLY .

As for your engine.

I am not a boat mechanic so please understand my advice is GENERIC. I was a Chevy and Jeep heavy line tech for years so I have been through HUNDREDS of motors..

Looks like you have a couple problems. Heat being the first. The piston melted for one of a couple reason. most likely LEAN mixture. this could be a carb problem. or a vacuum leak. SO if you do rebuild the motor.. think about that. you dont want it happening again.

The main bearings.. looks like you may have SPUN on. OR just overheated it. hard to tell from the pics. I am going to say (just a good guess) lack of lubrication. this could be from several things. Possible HEAT from the lean running cyl. OR it could have been damaged from the piston sezing up. remember it didnt just seize in one rotation.. it went around a bunch of time causing more damage each time.

Here is my suggestion.

HAve the crank turned.. crank turning is not super expensive. you haveto get new bearings so a fresh crank journal will be your best bet.

Yes new pistons. I would say First oversize (use your mic. and check the bores.) you might need to go .030 over. not sure what is standard for that kind of motor.

once you do that. think about a new oil pump. remember that is the HEART of the motor.. oil is the lifeblood.

NOW don't listen to the neigh sayers.. even on the MOST complicated motors out there. rebuilding a bottom end is not all that tough. the hard part is usually getting to it, and getting it back in and together.

Last thing. check the surface of the head. if it was that hot, it probably is warpped. resurfacing is a possibility.

Last thing. you messed with the fuel (added additives.etc) DUMP it start fresh.

I hope this helps out. good luck.

Dont feel to bad bro, I bough my first boat last year. took it out once. ended up doing an intermediate housing. then had to do the motor (froze and cracked it) now i have water in my upper.. so I have had it out twice this season and it's still not 100%... but hey it has been fun and I learned alot. I know this boat inside and out.

Take you time ask lots of questions. you can do it. and when you are done you will have a feeling of pride yo never had before in your boat.. because you built it!!

Thanks for the thumbs up Metal wizard, If the crank journals are ruined then i'll scrap it because it's too dear over here to have work carried out on cranks as it's only a few places countrywide that'll do it. if they turn out to be ok then i'm rebuilding.. The head has been inspected at the shop and we will replane it although it looks fine.
other than that I'll have to wait until I get the pistons (0.030 is what's req).

 

[Haffiman]

Re: I can't believe this happened

I hate to be a party killer, but if you are looking to get a reliable engine by using that crank, you may have better odds playing the lottery.
With pistons, rod, bearings and all the work I would have started looking for a new power head, or at least a replacement crank.
Have a look at this site, they even ship internationally:
http://www.crowleymarine.com/powerheads/johnson_evinrude/three_cylinder.cfm

 

[fishfeatures]

Re: I can't believe this happened

Guys, let me put this into perspective, I have said is crank is bad then I'll rethink the plan, but my situation is this , 3 oversize piston with kits off the net inc shipping are setting me back 168 euro , now 3 oversize piston with kit from one of the main dealer in Ireland for BRP is wanting just over 200 euro EACH ! imagine at that what a new crank or aused head would be. bear with me , I don't think this is too much , I have a good idea of what I'm at i'm only here looking for advice on parts i'm not too certain of.

Let me wait until I see how the crank is before this goes any farther..

 

[iwombat]

Re: I can't believe this happened

metal - oil pump?

Maybe you mean rebuild the carbs. Carbs are a two-stroke's oil pump

 

[metalwizard]

Re: I can't believe this happened

Yep was NOT thinking two stroke... that may be something to think about... do you premix or is it oil injected? this may have been part of your problem.

something to think about. if you premix, what ratio are you running? remember as you add oil to the mixture you remove Fuel,but the air stays the same. some people say more oil is better, BUT don't forget more oil makes for a leaner mixture.. and a hotter running cylinder. that can lead to a meltdown.

Check you mix make sure its right for the carb setup, if its injected make sure they are working correct.

Just food for thought.

again sounds like you have a good grasp on the mechanical repair. don't forget the "Why did it happen" or it could happen again.

 

[Monte1961]

Re: I can't believe this happened

Yep was NOT thinking two stroke... that may be something to think about... do you premix or is it oil injected? this may have been part of your problem.

something to think about. if you premix, what ratio are you running? remember as you add oil to the mixture you remove Fuel,but the air stays the same. some people say more oil is better, BUT don't forget more oil makes for a leaner mixture.. and a hotter running cylinder. that can lead to a meltdown.

Check you mix make sure its right for the carb setup, if its injected make sure they are working correct.

Just food for thought.

again sounds like you have a good grasp on the mechanical repair. don't forget the "Why did it happen" or it could happen again.

metalwizard(WRONG)!

 

[metalwizard]

Re: I can't believe this happened

metalwizard(WRONG)!

really? I worked for Yamaha as a Mechanic. thats the way every PREMIXED two stork i have ever worked with went, and thats what Yamaha teaches.. but boats must be different.

I guess all those Race Rz350 Tz250 and rz500's I built for the track Must be backwards.

 

[AlTn]

Re: I can't believe this happened

must be...additional oil to any mix will never make it burn leaner, in fact, it'll become so "rich" it can't sustain sparked ignition

 

[boobie]

Re: I can't believe this happened

We're not running on Tracks here, we're running on Water. The worst you can do on an outboard with to much oil is foul spark plugs.

 

[Monte1961]

Re: I can't believe this happened

I have to admit that anyone who has worked on anything other than outboards will have a hard time adjusting to how two stroke outboards really work. Auto and Diesel pros will be totally lost due to the fact the principals maybe the same, but attack is totally different on how it works. As far as I am concerned, if you don't really know anything about how they work, read some other posts regarding same issues before giving any advise on what member should or should not due. Boobie is right, were on the water and not on wheels.! If the member gets in over his or her head, I am sure they would let us know. And as for the member of this post, I would keep working on this. Crank journals and rod resizing are done all over the world in many machine shops. It's just a matter of money. After this is completed, you will have a almost new powerhead plus the experience in helping others in there delima! See you on the water!!!!

 

[metalwizard]

Re: I can't believe this happened

must be...additional oil to any mix will never make it burn leaner, in fact, it'll become so "rich" it can't sustain sparked ignition

when you add oil to premix. it takes up some of the space that USED to be fuel that means in the same Area you have less fuel. meaning with the same jetting you have a leaner mixture when you add more oil. its physics and it does not matter if its in a boat car motorcycle airplane scooter or weed wacker.

it may become OIL rich and foul plugs more because of too much oil. but your fuel/mixture is still leaner. period. it will be more OIL RICH, it will lubricate better, but as far as how it burns.... it is a leaner fuel/air ratio. a leaner fuel air mixture tends to run hotter and also tends to ping or detonate easier. THAT is what will cause damage like he has in his motor (burnt damaged pistons and or rings) his damage is NOT from lack of lubrication. lack of lubrication to your rings and pistons will show scars and scrapes on the cylinder walls.

anyways I don't need to argue with a anyone about it. think what you want. I know what 15 years of training and experience has given me. read here http://www.bridgestonemotorcycle.com/documents/oilpremix6.pdf

"fishfeatures" don't check your mixture or your carbs or your oil injectors if you have them.. they are just fine the way they are... your motor just burnt up because the planets are out of alignment or sunspots or something...its one of the things you will have to deal with when building and fixing engines.. sometimes they just fail for no reason whatsoever. put it back together just like it is you will be just fine.

 

[jonesg]

Re: I can't believe this happened

when you add oil to premix. it takes up some of the space that USED to be fuel that means in the same Area you have less fuel. meaning with the same jetting you have a leaner mixture when you add more oil. its physics and it does not matter if its in a boat car motorcycle airplane scooter or weed wacker.

it may become OIL rich and foul plugs more because of too much oil. but your fuel/mixture is still leaner. period. it will be more OIL RICH, it will lubricate better, but as far as how it burns.... it is a leaner fuel/air ratio. a leaner fuel air mixture tends to run hotter and also tends to ping or detonate easier. THAT is what will cause damage like he has in his motor (burnt damaged pistons and or rings) his damage is NOT from lack of lubrication. lack of lubrication to your rings and pistons will show scars and scrapes on the cylinder walls.
.

Yeh its physics.
Extra oil does lean the fuel mix but the added oil is still in the mix, the fuel mix becomes less volatile,
the extra oil protects the scenario you are predicting. Unless the mixture (carb) has been changed the intake volume remains the same.

It is a problem with 4 strokes due to the incompressability of oil, it raises compression and causes detonation.
4 strokes "button up" a lot sooner on the compression stroke than 2 strokes.
It will not cause a 2 stroke to detonate.
It can easily cause problems in a 2 stroke deisel, thats why they have contra pistons, to lower compression.

 

[Ben Clegg]

Re: UPDATE: I can't believe this happened (photos attached)

Re: UPDATE: I can't believe this happened (photos attached)

Hi Fishfeatures
Just been reading your post , how are you getting on with the engine, did you manage to get it sorted?
Ben

 

[fishfeatures]

Re: UPDATE: I can't believe this happened (photos attached)

Re: UPDATE: I can't believe this happened (photos attached)

Ben,

After getting a bit caught up in the resto of the boat itself, it has stretched out longer than expected. Planning on getting around to the motor in the next week or two though. Anyway I thought I might just wait until you finish yours so I can follow the step by step instructions you'll be posting soon

 

[fishfeatures]

Re: UPDATE: I can't believe this happened (photos attached)

Re: UPDATE: I can't believe this happened (photos attached)

Guys,

the shop over here doing the re bore doesn't just do marine but everything out there. we don't have specialised shops for this kind of work but my question is....

they won't rebore unless they have got the piston,I gave him the specs told him i was buying a 0.030 os piston for it but he still won't do it until he has the piston in hand, is this the usual way ?


Also i spoke to him about reboring just one cyclinder on an outboard and he has said "NO NEVER " as it will unbalance the engine, the reason I ask is that I may be back here with a v6 looper and I only need 1 done. If i push him to only to 1 would it have any adverse effect on a 2 stroke??

 

[Ben Clegg]

Re: UPDATE: I can't believe this happened (photos attached)

Re: UPDATE: I can't believe this happened (photos attached)

they won't rebore unless they have got the piston,I gave him the specs told him i was buying a 0.030 os piston for it but he still won't do it until he has the piston in hand, is this the usual way ?

I had the same scenario, you need the piston and I think the reason is that tolerances are slightly different between piston manufacturers, so they physically need the piston to check and match the bore.
Regarding the shall I replace all pistons, as you know my situation was very similar and I have replaced them all and the main reason for this is that stripping the powerhead is a b!tch of a job and if 1 piston was damaged enough by heat (lack of lubricant/ water whatever) , I imagine you can guarantee the other were affected even if only minor.
Not that I know anything

 

[fishfeatures]

Re: UPDATE: I can't believe this happened (photos attached)

Re: UPDATE: I can't believe this happened (photos attached)

Just a quick update to you all,

I kinda got caught up in the restore of the boat so I left the motor till the end. I pulled it all out of where I had it sat for the last while and after reading all your great advice I set out on the road of rebuilding it.

And yes !!!!!!


the crank is now a doorstop.
It was out of round on the #3 journal .

Also that con-rod was shot too as that was out of round as well.
and rusting on one of the centre main bearings too

So between the price of a crank, con-rod, rod bearing, centre main , needle bearing, 3 x pistons, just to get it going. Then to get all the other bearings and seals if I want to do it right.
Common sense prevailed and I'm now in the hunt for a new powerhead ( or at least a good used one with good compression).
I think I have one tracked down but am dubious of the cost of it.

Well only time will tell and once I see it I may feel better. Should I be looking for anything in particular, I will pull off the head and check out the cylinder walls, and check for signs of leaks at the seals. Anything else ?? If anything I don't really want to pull the new to be powerhead apart. Seller says the compression is good all within 10% of 120.

 

[64osby]

Re: UPDATE: I can't believe this happened (photos attached)

Re: UPDATE: I can't believe this happened (photos attached)

fishfeatures,

Sorry to hear about the door stop, or crank. Sounds like a quest for a decent used motor over there.

Can you find good deals on a rover series IIa rear axle, I'll find a power head and we can trade.