1996 Johnson 115 60 degree lower bearing failure

Daveparm

Petty Officer 2nd Class
Joined
Sep 13, 2014
Messages
122
Hey all,

If you happened to catch a post I had a month or so, I purchased a boat that had a bad motor. I swapped the powerherad and finally got around to tearing down the seized one. First off i gotta say, "I love these motors". Entire teardown went faster than most other motors I have rebuilt and not one broken bolt. (sure beats my last Suzuki lol.)

Unfortunately the motor had sat for a few months before I purchased it, so I didn't get a chance to see it freshly after it froze. As far as condition, the lower two cylinders/pistons were oil free and dry and rusty. The upper two were perfect, including a nice coat of oil. The upper rod bearing on one of the lowers (not at home- forget which one) had come apart and is the reason for the failure. The case was good except for one of the journals that had some scraping from a loose bearing. The crankshaft was dry on the lower two cylinders but had a heavy pool of lubrication at the lower bearing/main seal. Heavy scoring on one of the lower cylinders from a bearing and moderate on the other. The thermostats --one was tested o.k., the other was stuck mostly open.

My question is this. From the above (will try to post photos later) is there a most likely cause? Overheat? lubrication (premix motor though) , lean seizure? Vacume leak (lean seisure)? Were the cylinders dry because they were on the exhaust stroke when it seized and not a result of it?

I really like my now running (same model) motor, but potential issues with all the balance tubes and vacuum lines scare me. My running motor is premix with a traditional high volume pump feeding the original vro pump (minus the oil). Are there things you more experienced with this motor could recommend to simplify or improve on the intake side of the motor? Is there anything I should retrofit/replace that are known to fail. As easy as these are to tear apart, I would hate to have to loose a bunch of time and money doing it.

Thanks,
Dave
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,033
And why do you think cylinders ----" were dry because they were on the exhaust stroke when it seized "----Can you explain that question ?----Note---There is no " exhaust stroke " on a 2 stroke like there is on a 4 stroke motor.
 

Daveparm

Petty Officer 2nd Class
Joined
Sep 13, 2014
Messages
122
O.K. So I meant the power stroke. Would be dry due to those ports being more open to the Florida humidity, as if the piston stopped in that position they wouldn't have the reeds and carb throttle/choke plates sealing them off. They would also have less lubrication if it stopped at this point in the revolution as more of the oil would have burned off in the power stroke.

Have purchased many a PWC engine that sat seized simply from sitting that way. Motors of that type do have a box that traps water if it isn't properly blown out after use though.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,033
If a motor is not turning then the reeds will be CLOSED !-------And why the 2 fuel pumps as per post # 1 ??-----And do you really understand what happens to the oil once it goes through the carburetor ?-----As where does it go and how long might a particle of oil stay inside the motor ?
 
Last edited:

Daveparm

Petty Officer 2nd Class
Joined
Sep 13, 2014
Messages
122
Yes, that is why I am saying that when the motor is stopped with the exhaust ports open, the EXHAUST side is exposed to the elements. If the other way around piston blocking the exhaust, the reeds and carb (all closed) protect the cylinder from the elements when it is not running.

I wasn't hoping for this to be a debate on semantics though, as these have nothing to do with the original question.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
12,944
Perhaps the motor sat slightly submerged for a while
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,033
In post #1 what lower bearing are you referring to.------Post some pictures of this mess.
 

Daveparm

Petty Officer 2nd Class
Joined
Sep 13, 2014
Messages
122
As far as the 2 fuel pumps, I just want to make sure my running motor is up to par. I suppose two fuel pumps were put on due to the fact that the fuel needs at WOT wouldn't be sufficient with one. It wasn't a modification I did, so was wondering if that is something that is O. K. or done with these.
 

Daveparm

Petty Officer 2nd Class
Joined
Sep 13, 2014
Messages
122
I will post photos when I get home. Everything is in bags now. I tore it down last week but just recently got to thinking that it would be nice to know it there is anything that I should pay particular close attention to on these.

If it wasn't clear in my first post, I am talking about two different powerheads. One running fine that I would like to keep that way. And one that was seized when I purchased it as was trying guess what happened to it.

As far as partially submerged, good guess, it would back up the fact that the driveshaft was severely stuck to it., The outside portion had no signs of corrosion , but it could have been rinsed off.

My main concern here is what to do to give the running powerhead and long and healthy life. I will take photos of it (and the double pumps) in the morning as it will be dark when I get home.
 

Daveparm

Petty Officer 2nd Class
Joined
Sep 13, 2014
Messages
122
So here is my running motor. The photo that shows the fuel pumps is how the previous owners mechanic set this up ( i know the main fuel line isn't connected). The aluminum bracket that holds the pulse line to the extra pump is all it does. The pump isn't supported with a bracket. If I keep this configuration, i will fabricate a bracket. My guess is it was either done this way to eliminate any possible fuel starvation at WOT, or he didn't have the adapter(connector) that would allow the traditional pump to connect to the vapor separator. Who Knows??

The second photo shows the wires to the trim motor. They are just individual female spade connectors connected to the males in this plug. Is that right?? Sure doesn't seem so? Weird thing was that the other motor was hooked up the same way. I wasn't quite sure by looking at parts diagram, but is this the part I need (0513664)

The third photo showing the balance tube looks like it was epoxied. What will a leaking balance tube cause? Should these be replaced with new on an old motor?

Thanks!
 

Attachments

  • photo307794.jpg
    photo307794.jpg
    373.3 KB · Views: 1
  • photo307795.jpg
    photo307795.jpg
    394.1 KB · Views: 1
  • photo307796.jpg
    photo307796.jpg
    358 KB · Views: 1

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
12,944
2 different motors with different issues/problems in one thread is gonna get very confusing very quickly
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
That's a cobbed together repair and it going to cause more problems...The air cover is missing and it is a restrictive design,unless the main jets was increase it will run lean at WOT
 

havoc_squad

Senior Chief Petty Officer
Joined
Mar 5, 2011
Messages
693
Looks like the wrong pump installed, almost like the 2/3/v4 crossflow crank pulse hose driven fuel pumps.

If it is, that pump on there won't supply enough fuel output for that 60 degree motor.

I hope the VRO fuel pump mounting holes are still intact of that crappy hack job.

Mastertech marine has the best aftermarket designed pre-mix only pump kit for the money that should allow you to install the airbox back on for a 60 degree v4 using the VST system.

They also provide installation instructions.

You will need to do your own internet research to find them, as a link posted here may go against iBoats forum rules about parts links to competitors.
 
Last edited:

Daveparm

Petty Officer 2nd Class
Joined
Sep 13, 2014
Messages
122
Hey thanks for the responses, I had to run out of town, sorry for the delay. Sorry to switch gears on this thread, even though my goal was note any common lean seizures on this model due to the nature of the many possible vacuum leaks, I did get off topic. please just a little more on the VRO though.

I had the air cover off so I could get a better photo of the layout. It will be put back on before I run it. I haven't had this motor on the water yet, as I just changed the powerehead to this one and just remounted the motor on the boat. If you notice, the VRO pump is still there. This other pump is just feeding the VRO one. I guess I could just remove it, and test the output of the existing VRO as per the manual . Unfortunately I wouldn't be able to do the initial vacuum test as I would need a prop wheel for the full throttle initial part of the fuel system check. I guess I could just check for 3psi fuel pressure at idle, and not worry about air leaks for the moment. The mounting plate wasn't modified at all. Looks like they just used a pulse fitting to the new pump which supplies the existing VRO pump and just let it hang by the hoses. Unlike the mastertech system, the guy that did this ran this pump inline with the existing VRO. Is there a benefit to using the mastertech pump on a premix motor rather than a VRO only if the VRO still works?



Not sure if this helps at all (unrelated), but here are photos of the bad powerhead. Guesses on what its demise was? Again this motor used premix and a single VRO pump. Tank in boat (new to me) did have had oil in the gas & just assuming it was the correct ratio. I could be off in my cylinder numbers, but the bottom two are rusted, only severely damaged liner was bottom starboard. best way to tie this thing together--..any chance it was due to a lean condition. ( I forgot if the owner it failed on mentioned if it happened at idle or full throttle--sorry)
 

Attachments

  • photo307835.jpg
    photo307835.jpg
    476.9 KB · Views: 0
  • photo307836.jpg
    photo307836.jpg
    416.3 KB · Views: 0
  • photo307837.jpg
    photo307837.jpg
    577.8 KB · Views: 0
  • photo307838.jpg
    photo307838.jpg
    554.8 KB · Views: 0
  • photo307839.jpg
    photo307839.jpg
    470.8 KB · Views: 0
  • photo307840.jpg
    photo307840.jpg
    417.9 KB · Views: 0

havoc_squad

Senior Chief Petty Officer
Joined
Mar 5, 2011
Messages
693
Consider this question. Assuming that the motor now has the VRO fuel pump with just the oil injection disabled/capped and ran pre-mix only, why would it need another auxillary fuel pump that the original manufacturer never put on it?

Putting an extra wrong fuel pump on top of another failing/weak fuel pump (VRO fuel pump unit) makes no sense, it is like using a vehicle to bumper push another vehicle that doesn't have enough power to accelerate and hold speed.

Extra wear and tear for little gain.

If the original VRO fuel pump puts the proper fuel output without leaks, then use it without that extra fuel pump.

Other wise its buy OEM replacement VRO/OEM pre-mix only pump, or Mastertech's pre-mix only option.
 
Last edited:

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,033
??----Rust damage like that is NOT a result of exposure to the Florida air.-----It was submerged in my opinion !!----Also mechanical damage at one port.----The top cylinder on this motor is # 1 and the bottom is # 4
 

Daveparm

Petty Officer 2nd Class
Joined
Sep 13, 2014
Messages
122
Thanks guys! I suspected as much. I will test the two VRO pumps I have (each powerhead) for 3 psi pressure tomorrow. Is there anything else I can do to ensure they are up to par? As far as VRO rebuild kit, I didn't see one here on Iboats. Is one available? Or, If I get to that point, am I just better off with the mastertech option. Prob won't go back to injection as I would need to source tank, lines and still have the worry of replacing a $500 pump.

Yeah, I did notice that heavy damage to the port. It's amazing there wasn't a lot more to other cylinders as the bearings were everywhere. Submerging does fit. Thing that made me doubt it was that there was no corrosion on the outside of the powerhead or any of the electrical connections. carbs looks good as well. I guess a quick dunk is all it takes. if it was a non V would surely have thought head gasket.

So is it that the numbering starts at top starboard as #1 and ends on bottom port #4. I see firing order 1234
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,033
??-----The numbering has always been with #1 as the top cylinder and #4 is the bottom.------And why not take the VRO apart before jumping up and down and worrying about a kit / new pump.----There may be nothing wrong with it.----VRO gets blamed for everything because folks do not understand them..
 

Daveparm

Petty Officer 2nd Class
Joined
Sep 13, 2014
Messages
122
Hey guys, definitely good advice on removing the dual pump contraption thing. Turns out, a second pulse line was never tapped. Whoever did this was just running gas through the VRO without a pulse. :eek: . As racerone suggested I took apart the pump that was on the bad motor, looked o.k. so back to stock (sort of- no oil injection). Two concerns though. That pump didn't have the oil pump part attached to the top of the pump. See photo. Looks like the center opening was capped. Was this modified, or was it off a commercial (premixed?) motor or something?? Is it ok to run this way?
And when shifted to forward, the shift linkage pushes up against the pulse fitting. I guess that's the design, but with vibration, sure seems like a pulse hose air leak in the future

Yup there I go worrying. :)
 

Attachments

  • photo307859.jpg
    photo307859.jpg
    366.5 KB · Views: 1
  • photo307860.jpg
    photo307860.jpg
    346.7 KB · Views: 1
Top