1984 merc 115 reed valves

[GHBART]

Can the reed valves be inspected and/or replaced without removing the crankshaft, tierod and piston assembly?

 

[Faztbullet]

Re: 1984 merc 115 reed valves

You can look at them with carbs removed but your limited to what you can see. Why do you need to inspect them?

 

[GHBART]

Re: 1984 merc 115 reed valves

Last spring ignition was erratic on all cylinders, finally replaced Stator and both Switch Boxes.
The Idle Stabilizer was removed.
At this point the ignition was looking great. All cylinders were equal and I had a great steady spark on all cylinders looking at the spark with the plugs outside the engine.
Compression on all cylinders 90-100 letting it rev about 5 times.
Rebuilt all carbs.
Timing was done very carefully to the instructions.
Lake trials produced the following result.
I could adjust the carbs to idle great, however I could not accelerate without stalling unless done very carefully.
I also could adjust the carbs so the acceleration was great, however the motor would idle only a very short time.
We had to make our annual Green River ? Colorado River 180 mile trip.
The situation on the trip was as follows.
Once up to about 2500 RPM, we were in great shape at any speed above that but could not slow down much without stalling.
Restarting was a nightmare, always wondered if it would happen. And when it did, it had to be nursed to get it up to an RPM where it would run well.
I did no more work on it last year, also did not make any other trips.
So here I am getting ready for the same trip this year.
So in answer to the question, I believe the only thing I have not checked is the reed valves.
Before I wanted to open up the power head I wanted to know what I was in to so I would have everything I need before starting.
Long answer but thanks for responding .

 

[j_martin]

Re: 1984 merc 115 reed valves

Link and sync. Carbs need to open in unison, and the pickup point has to be just right on the timing. Also, it needs to idle rich to be able to accererate.

If it idles smooth at all, the reeds are good. That ain't the trouble. A bad reed will tend to completely drop the affected cylinder.

Your location begs the question; are the proper jets installed in the carburetors for the operating elevation?

 

[GHBART]

Re: 1984 merc 115 reed valves

Thanks for the imput. The answere on the reeds was welcome information. As soon as the snow stops here, I will Link & Sync again. I have some conflicting information on the proper settings for carb settings and timing and syncing of timing. If you have some good info, please lead me to it. Thanks Again. Bart

 

[Mi duckdown]

Re: 1984 merc 115 reed valves

Personally.
I would buy an OEM Merc Service/ Repair Manual for that Motor.
Best information you can have, if you plan on keeping that motor. .02

 

[Wingedwheel]

Re: 1984 merc 115 reed valves

For future reference, a typical sympton of bad/broken reeds is gas pouring out of the mouth of the carb.

 

[j_martin]

Re: 1984 merc 115 reed valves

Thanks for the imput. The answere on the reeds was welcome information. As soon as the snow stops here, I will Link & Sync again. I have some conflicting information on the proper settings for carb settings and timing and syncing of timing. If you have some good info, please lead me to it. Thanks Again. Bart

The right jetting for the altitude is important as a starter. Another item is to pay real close attention to throttle linkage, taking the slack out so that all the carbs open in unison, then set the gap or angle for throttle pickup.

 

[Chris1956]

Re: 1984 merc 115 reed valves

To be clear and accurate, gas pouring out of the venturi of the carb is a symptom of a bad carb float, inlet needle and or inlet seat, not a reed valve problem. Carbs with bad reeds will sometimes spit fuel+air back, however, factory reeds are real tough, and almost never break. Stick with John's advice