1980 Mariner 2cylinder 60HP No Power Under Load

[kmk89]

I have 1980 Mariner (Japanese Model) 2 cylinder 60HP. I had it out on the water a few week back, hit a huge amount of wake from another boat and the motor died. Pulled off the engine cover to find a sheared the flywheel key, damaged the flywheel keyway, and sheared off the starter cover shield. I replaced the following:

1) The flywheel was replaced with a working spare.
2) The flywheel key was replaced with a new one.
3) Flywheel torqued down to specs in my Mariner 48/55/60HP shop manual.
4) Starter cover shield replaced.
5) Fuel filter replaced.


Suspected problems that have been ruled out (at least by me):

1) The top of the crankshaft and the crankshaft keyway is still good.
2) No visual damage to magneto base and trigger components under the flywheel.
3) Compression is still an even 120 psi in each cylinder.


Suspected problem:

The motor starts ok in neutral, but it dies out when you give it throttle. I got it out of neutral once without it dying out and the top speed was about 5 mph and it sounds like the engine is misfiring or missing completely. I think it may be a timing issue because I replaced the flywheel with a different working one. I've never messed with the timing on any outboard. Any thoughts or suggestions for testing or possible problems other than timing?

 

[Faztbullet]

Re: 1980 Mariner 2cylinder 60HP No Power Under Load

Compare the magnet location on flywheels as parts breakdown show several different types..

 

[Anchor Marine Repair LLC]

Re: 1980 Mariner 2cylinder 60HP No Power Under Load

You have to decide if you have a fuel, spark, compression, timing or exhaust issue on every repair job.

Your flywheel and timing idea isn’t going to cause this type of lack of power. I'd be awful suprised if your motor was that retared in timing yet would start. A timing light would give you the easy answer here.

I think you have a big bore 2 cylinder that is only running on one cylinder. Pull your spark plugs and start gathering information from them.

Substitution is the easiest way to troubleshoot.

Pull the air silencer off or at least the access holes, then try to start the motor. If it stays running, dust some carb cleaner into one carb throat at a time. If it perks up on one or the other, you have a lack of fuel issue. No response, you have a spark issue. If it drops in speed on one but not the other, then the one that bogged down is getting enough fuel and you just temporarily flooded it.

 

[kmk89]

Re: 1980 Mariner 2cylinder 60HP No Power Under Load

Thanks for the input. I made an attempt today at fixing the motor. I tried to start it so I could see if it was running on just one cylinder, but now it won't even start. Then I pulled the air silencer off and tried starting it with some carb cleaner in the throat. Still no luck. I don't know if I just got lucky last time it started or what. I just hope I didn't make anything worse last time I started it. Anyway, I put a dial gauge indicator in the #1 cylinder (top cylinder) and found that at TDC, the TDC marking (there is actually marks all the way from 30 degrees BTDC to 10 degrees after ATDC) on the flywheel and the TDC pointer arm did not align. In fact, they are not even close. I can't even move the pointer arm enough to get the flywheel TDC marking and the pointer arm TDC marking to align. How can I bring the two into alignment? I have the shop manual, but I am new at this and can't seem to find anything. There are two other marks on the flywheel as well, but I can't figure out what they are for. Any ideas on what I should try?

 

[Anchor Marine Repair LLC]

Re: 1980 Mariner 2cylinder 60HP No Power Under Load

Well, I?d say so far you?re doing a great job.

Let me throw out some ideas:

If your timing pointer is close to the degree marks on the flywheel, but the pointer won?t adjust, then that?s good info. How many degrees exactly is it off? And is it retarded or advanced?

Any chance your flywheel key got loose and you torqued it without a key in there? Or it was jacked over to one side? Timing from the point of the key way out to your timing grid can get really far off. Kinda like rocket science.

With a timing light, point it at the pointer when trying to start. Where is it trying to fire? Timing lights are good cheap troubleshooting tools. They also tell you if you have spark at the plug.

Those other marks can be about anything. Post some pics?

As stated before, compare the 2 flywheels to ensure they are the exact same.

 

[kmk89]

Re: 1980 Mariner 2cylinder 60HP No Power Under Load

I will have to pull the flywheel off and compare the two. I completely missed Fazbullet's comment above about that.

I did make sure the key was in there and that it was completely vertical when I installed it. The timing pointer arm is not even close the marks on the flywheel. The labels on the flywheel (with the degrees and TDC markings) are about 1/4 turn away (about 90 degrees), however, the one of the other two marks on the flywheel that I mentioned earlier is somewhat closer. Maybe 20 degrees or so.

In the meantime, I will hook up my spark plug checker to check if I even have spark and I will take some pics to show what I am talking about.

 

[Faztbullet]

Re: 1980 Mariner 2cylinder 60HP No Power Under Load

Still say flywheel is incorrect as magnet and timing marks in different locations...

 

[kmk89]

Re: 1980 Mariner 2cylinder 60HP No Power Under Load

Had the shop take a look at it. Sheared the flywheel key again, damaged my new flywheel and now my crankshaft. Is there anyway to repair the crankshaft? could a machine shop even do it without removing it? compared the flywheels and they are identical. I can't figure out what went wrong.