Topic: 1963 Johnson QDL-24 10HP – Antique Outboard Motor Club,Inc

This topic has 31 replies, 9 voices, and was last updated 9 years, 6 months ago by steeleman.

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July 11, 2016 at 5:05 pm #4721
steeleman
Participant
Hi guys, took the carb off and need to hook the throttle back up to the carb. Do you just twist the throttle wide open so the mag is fully advanced and then hold the throttle open on the carb and set the set screw so both are wide open? Otherwise I’m not sure how to set the right timing between the mag advance and the actual throttle valve on the carb. Thanks in advance!
July 11, 2016 at 5:43 pm #40017
fleetwin
Participant
US Member
Well, there isn’t really anything adjustable here except for the slight movement on the throttle cam to set proper carb/throttle cam pick up point…
That brass arm fits only one way on the throttle shaft, the two flat surfaces line up and the screw clamps it in place.
Post some pictures so we can help because I fear I am not answering your questions….
July 11, 2016 at 10:01 pm #40027
frankr
Participant
I’m probably not answering it right either, but the carb throttle shaft should just barely begin to move when the roller is centered on the mark on the brass cam. Adjust by moving that end of the cam in/out. Hopefully, the roller isn’t too worn out.
July 11, 2016 at 10:47 pm #40032
steeleman
Participant
I am unsure how to add a photo, and I am away from the motor until this weekend. That i took apart would be part 39 from the shaft in the diagram here. https://www.marineengine.com/parts/john … etor+Group

It does not have a notch, it will go on in any position as long as you set the screw. I opened the throttle on the handle up full which allows the magneto to push the rubber wheel all the way down to full throttle. Then I held the throttle on the carb open full, pulled the linkage tight and set the screw. I am just concerned that It then advanced the spark too much. I did notice the notch on the mag that pushes the rubber wheel down. I will see where that notch is when I get back to it this weekend.
July 11, 2016 at 11:41 pm #40033
chris-p
Participant
SteeleMan,

As stated, the shaft will only fit in that linkage piece one way. Flat side of shaft, to flat side of the linkage piece. You can see the shape of it in your diagram actually. There is no adjustment there. There is nothing to adjust from simply taking the carb off, as long as the linc n sync was fine before you started of course.
July 12, 2016 at 12:00 am #40034
fleetwin
Participant
US Member
You can email pics to me if you like, I will post them for you…
old e-mail addy removed
Don
- This reply was modified 7 years, 2 months ago by fleetwin.
- This reply was modified 6 years, 1 month ago by seakaye12.
July 12, 2016 at 12:10 am #40036
steeleman
Participant
I understand what you are saying, but mine is not flat on one side nor is the throttle shaft. It will go on in any position. I have had it on in a few so I know this is correct. It is not exactly as it is in the diagram, that was just to show what I am talking about.

At first set it at idle and when you would twist the grip to full it would open the carb up yet it would not reach full RPM because the mag was not advanced enough. So I reset it with both at WOT as stated above. It does run fine, but I am afraid of advancing too much creating other problems like creating excessive heat, etc.

It is running good, just want to ensure it does not need to be in a specific position to not create long term problems
July 12, 2016 at 12:24 am #40037
fleetwin
Participant
US Member
Well, I’m pretty sure there is a "stop" on the throttle shaft that prevents the throttle shaft going past the WOT position and actually start closing again as the throttle is advanced. So, if you have the throttle shaft "pre loaded", excess pressure will be applied the throttle shaft and could cause premature wear.
I’m confused though, because #39 should have a flat spot that corresponds to a flat spot in the throttle shaft….
July 12, 2016 at 12:30 am #40038
steeleman
Participant
I don’t know what you mean by pre loaded?

But yes, a flat spot would make this 100% easier. I will take pictures this weekend when I am back home. I do not know why this one is different, but it is. I am 100% certain it does not have a flat spot. As I have said, I’ve out it in a few different spots to try it.

The throttle in the carb does stop at wide open. It would not be able to spin past that connected or not. It only just comes off of fully closed when in the start position when locked against the stop connected to the shift level. That is why I also feel it might not be right.
July 12, 2016 at 1:10 am #40039
fleetwin
Participant
US Member
True, the carb throttle shaft can not go past the WOT position, I think there is a roll pin that hits a stop on the carb body….But, if the linkage is improperly installed, the throttle cam may try to push the throttle shaft past the WOT position which will just put excess pressure on the throttle shaft because it can’t go past the WOT position. The excess pressure (preloading) can damage, cause excess wear on the throttle shaft and carb body….
The carb butterfly is supposed to be closed at dead idle, and a little past idle position. There is a little notch on the throttle cam that should bisect the throttle roller when the butterfly is just starting to open….
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