1986 mariner top speed is missing i think

[rickjm1001]

Hello,

I just got a mariner 1986 i believe is the year.
When I'm only at top speed or over 3/4 speed I think the motor is misfiring.
It makes a stuttering sound.
I rebuilt the carburetor thinking it was dirty and still the same issue arises.
It does not do it consistently but very erratically.

Is something wrong with the ignition coil or cd box?
Why only at top speed?

The parts are so expensive when it comes to the ignition, the cdi box is 300 dollars CAD. and the ignition coil seems to be just as much... OUCH!!

Thanks in advance for any advice.

 

[Maxz695]

Re: 1986 mariner top speed is missing i think

check for loose wire or bad coil wire and change the plug. Spark plugs can fire up to a certain amount of pressure then fail. This seems to be whats happening. just trying to see if it might be a simple fix for you before you go the $ route.

 

[rickjm1001]

Re: 1986 mariner top speed is missing i think

check for loose wire or bad coil wire and change the plug. Spark plugs can fire up to a certain amount of pressure then fail. This seems to be whats happening. just trying to see if it might be a simple fix for you before you go the $ route.

• 
  Yes I have tried changing the plugs, rebuilding the carb.
  There is a screw at the side/top of the carb. fuel adjustment?
  I'm not sure, but am I supposed to adjust this at WOT?
  I'm starting to think that my problem might be more of a fuel air mix issue.
  as I was playing with this screw at WOT and the problem was going away.
  It's not completely perfect but maybe someone who had some experience with carb rebuilding and adjustment can chime in.
  
  Can some one also point me to a repair manual?
  
  Thanks,
  
  Rick
  

 

[Maxz695]

Re: 1986 mariner top speed is missing i think

at idle turn the screw in until you here it start to cough then back out 1/2 turns then after doing this several times to get it as best you can turn out 1/4 turn and try running it again

 

[Faztbullet]

Re: 1986 mariner top speed is missing i think

Uh...what horsepower we talking about? How about serial/model number?

 

[Maxz695]

Re: 1986 mariner top speed is missing i think

I,ve been wondering alot about the CDI and the cost of the replacement parts you can,t use a CDI stator with the old style glued in magnet flywheels but stators from the old style engine can run with a CDI screw typ flywheel I have a stator and flywheel from a 40 HP 1997 40 HP 4 stroke 4 cylinder that will replace certain cdi setups. If i do buy the 155 HP Merc upgrade from my now 40 HP tinker toy I will not get the CDI stupI have too many extra parts lol

 

[rickjm1001]

Re: 1986 mariner top speed is missing i think

I don't have the serial # with me but I belave the year is 1986 9.9HP
Made by Yamaha, I say made by Yamaha because it's the same Japanese company that made this outboard for Yamaha.

Ok so if screw is only to adjust the odle fuel mix then I'm guessing I have ignition problems?

 

[Faztbullet]

Re: 1986 mariner top speed is missing i think

That is the Yamaha motor and rarely do you see a CDI/pack fail on a Yamaha engine. This engine came 2 ways,with CD ignition(single coil) or magneto(2 coils) The CDI coil fires both cylinders at the same time. On the CDI engine, disconnect the white wire from the CDI unit as this disables the stop switch if it runs ok its is dirty or bad. If it still acts up ,ohm the charging coil. Measure from the brown wire to armature base, you should read 81-99 ohms(Rx1).

 

[rickjm1001]

Re: 1986 mariner top speed is missing i think

Hello,

Yes it's a single coil.
If it's not an ignition problem, I'm not sure what else can be wrong as the compression is 112 on both cyl.

When I was able to get the motor to top speed I would close the choke half way to see if I could recreate the issue and it feels the same way as when I close the choke.
It stutters and slows me down.

Well to the same effect anyway.

Also I am having a very hard time pulling the flywheel.
With a gear puller it does not seem to move.
I'm worried about applying to much pulling force.

I'm not sure what you mean oms the charging coil.
I do have an oms meeter. What's the procedure?

 

[rickjm1001]

Re: 1986 mariner top speed is missing i think

I don't know if I did this correctly.
But anyway, I disconnected the brown wire used oms meter on brown wire from under the flywheel and ground, the needle went all the way across. I guess this means no resistance?
Then I checked the brown wire from the cdi pack to ground and the meter read 195 oms?

Like I said I'm not entirely sure if I'm doing this correctly.

 

[rickjm1001]

Re: 1986 mariner top speed is missing i think

I just wanted to add that I pulled the carb off again to have a look at the reads and they look fine.

 

[rickjm1001]

Re: 1986 mariner top speed is missing i think

Is it possible that the ignition timing might be off?
I see timing marks on the flywheel but how do you adjust it?

 

[rickjm1001]

Re: 1986 mariner top speed is missing i think

anyone?

 

[Faztbullet]

Re: 1986 mariner top speed is missing i think

Is it possible that the ignition timing might be off?
I see timing marks on the flywheel but how do you adjust it?

Doubt its off. You will need a dial indicator to set it as you need to find TDC, after that you just align the magneto base and flywheel timing marks...

 

[rickjm1001]

Re: 1986 mariner top speed is missing i think

OK thanks Faztbullet.
Ya I doubt it off to. Well I guess I'll just drop a can of seafoam in a 3gal fuel/oil mix and that should help cleanup the motor?
Or is that to strong?