225hp Johnson Spark Dwell Adjustment

[rlasiak]

I just purchased a 1988 20.5 Bayliner Trophy CC with either a late 80's or early 90's model 225hp Johnson. The motor runs well but I noticed that the rod that holds the nut for the spark dwell adjustment was not seated completely possibly allowing the nut to move on its own. Can someone please tell me where the correct position is to set this as I'm not sure if it is where it needs to be. Is there a procedure to adjust this? I am a diesel mechanic and am somewhat familiar with outboards but have not come across this yet. I appreciate any help you can give me. Thank you!

 

[ondarvr]

There is no dwell, you just set the max advance on the timing and you're done. The max timing should be marked on a sticker on the motor.

 

[rlasiak]

My motor has a long black plastic rod coming off of the port side of the motor that has a nut and a jam rod to hold the nut in place with a sticker in front of it that says spark dwell adjustment. I have been trying to upload pictures but the forum keeps saying that they exceed the maximum allowance of bytes. I would really like to know exactly what model and year it is also so that I can order a factory service repair manual but the model # sticker is missing. All I have is the serial # from the freeze plug. Any ideas are welcome. Thank all responders for your valuable time.

 

[interalian]

You can upload your pictures to photobucket and link them. That site has become quite nasty but is still marginally useful for posting temporary pix.

 

[Strangeleak]

Are you sure it on the port(passenger side) of the boat?

If its the model i'm thinking of, its the driver side and it does say dwell on the air silencer on my engine as well.

The long black plastic rod is use to adjust your timing. It also effects how quickly you achieve max timing in comparison to throttle input. Does not "set" max timing though. Thread out to advance, thread in to retard.
If it turns out to be a '91 model, I have the OMC Manual for that year. A lot of info that would be useful for other year models as well.
Let me know if you need anything out of it.

IF that is a 1991, the V6 max timing should be 16? BTDC ?1?. I'll double check my manual when I get home though. I'll also check what idle timing should be.

 

[rlasiak]

I'm sorry, it's on the starboard side. Which would be the passenger side on my center console. I appreciate the answers. I will definitely try to get the pictures uploaded to photo bucket here shortly. Is there an exact procedure to adjust it? I will gladly purchase a copy of your manual if my motor is indeed the same year.

 

[rlasiak]

I don't know if it would help with identifying my motor but the serial# on the freeze plug appears to be 63041957

 

[rlasiak]

It's definitely on the starboard, passenger side. I have uploaded my photos to Photobucket. How do I link them?

 

[rlasiak]

Did this work? It's the long black rod right under my flywheel.

 

[rlasiak]

Any ideas on year and HP?

 

[Strangeleak]

Yes it did!

There is a complete link and sync procedure in the manual. Unfortunately I still own the engine for this manual and would like to keep them together. But I'll be more than happy to take photos of any page you need.

I can't help with the serial number on the welch plug, though.

For year model. Try finding a part number on the carbs and posting them.

OMC often made slight changes to the carbs over the years and changed the part# accordingly. Cross referencing the carb numbers might get you a year range.

It could also muddy the water though. In my case, my 1991 120HP V4 Looper has carbs from a 1986 225HP V6 Looper on it with jets that were never installed on either combo of Year/HP!

 

[Strangeleak]

Are you sure it on the port(passenger side) of the boat?

If its the model i'm thinking of, its the driver side and it does say dwell on the air silencer on my engine as well.

My apologies, I wrongly picturing a boat with a console on the RH side of the boat.

Either way, if you're in the boat facing forward...

Port = Left
Starboard = Right

 

[rlasiak]

Yes sir. Will do tonight. Could you send me a copy of the link and sync procedure when you get a chance please? I will be doing my carb rebuilds before summer so that will be a great help. I was just concerned about discovering the jam rod you could say being backed off and the possibility that the adjuster nut may have moved. Is that covered in the link and sync or timing? Have you had to adjust yours? I just wanted to make sure it's in the right position until then so that I don't cause any harm to my motor. Thank you!

 

[Strangeleak]

Yeah I'll send the pics tonight. It may not need it but will be good to perform as a new owner for piece of mind. Also, if your just pulling the plastic carburetor bodies for cleaning, then a link and sync isn't necessary afterwards.

Everything about the timing is covered in the link and sync. I just performed mine last month for piece of mind.

The timing adjusting rod controls idle (not the carbs) and makes very slight timing adjustments and, alone, can't hurt the engine. What you should be most concerned with is the max timing advance stopper. Should be a metal threaded rod with a flat head cut into the end of it near the black plastic rod but more so under the flywheel. There will be a metal jam nut keeping it secure. If that is threaded out to far (too advanced), AND the black rod is threaded out too far you can damage your engine at WOT. If both/either are too retarded you won't get max RPM/Power.

You will obviously need a timing light for both idle and max timing. You will also need some time at the ramp for idle timing adjustment(Engine running in gear)

Max timing advance can be set in your driveway using the Joe Reeves method.

 

[rlasiak]

Yes sir. Thank you very much. I have a timing light and will verify that all is in adjustment. I also have a ramp where I can check it in gear. I greatly appreciate all of the help.

 

[Faztbullet]

The Morse cable set up is the reason someone installed a spring on advance arm...that needs to get gone before it winds up in flywheel. Its jhad a CDI timer base installed(blue) and set the timing at 3 degrees below setting as if you do not have a test prop to set it with Also 1 turn equal close to 1 degrees on stop. Johnrudes gain timing as RPM increases and Mercurys retard.

 

[Strangeleak]

Reminder: This is for the 1991 year model of these HP ranges.

If your engine is a different year then these may not be accurate.

Not sure why, but it turned the pictures sideways.

 

[rlasiak]

Thanks so much for the info Strangeleak it will be a great help. But Fatzbullet I understand your post and I am extremely grateful for your help. But what do you mean by 1 turn equals one degree on stop. Once again I greatly appreciate your help.

 

[Strangeleak]

Fazt is talking about the max timing advance stop that I mentioned.

1 Full turn equals about 1? of timing in the corresponding direction.

Out = Advance
In = Retard

 

[rlasiak]

10-4. Going to get it done this weekend and will let you know how it turns out.