1975 135HP Johnson Carb Linkage

Randyg123

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I've finally received my Johnson Service Manual and have read through it.

I was getting ready to perform some of the basic carb linkage adjustments when I noticed a discrepancy.

The manual shows a solid link between the two throttles, while the choke link is two parts with an adjustment connector in the middle. Mine is just the opposite. My throttle-to-choke link is shaped different as well.

Is this a minor factory variation and to be ignored; or has someone slapped on different carbs; or worse, 'adapted the linkage'?

Plus it appears my Manual Choke lever assembly is missing. Will this affect the operation of the engine (other than I have no manual settings)?
:)thanks:)
 

tashasdaddy

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Re: 1975 135HP Johnson Carb Linkage

as long as the throttle plates are in the identical position, when you move them, you will be all right. if not swap the connectors. all the link on the choke does is close the choke butterfly. the reason for the link adjustment it to get the butterflies identical. as long as your choke solenoid works i would not worry about the manual lever. you would only use it if you have to rope start it. which i hope you never have to do with a 135. i can be done.
 

Randyg123

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Re: 1975 135HP Johnson Carb Linkage

as long as your choke solenoid works i would not worry about the manual lever. you would only use it if you have to rope start it. which i hope you never have to do with a 135. i can be done.

Hah, How many times I wish I had a rope starter:eek:

Running the electric till dead and then paddling a few extra hours makes the "Rope Workout" seem a bit pleasing:rolleyes:

Thanks for the advice. That was what I was hoping to hear.
 

Randyg123

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Re: 1975 135HP Johnson Carb Linkage

I will be checking/adjusting the WOT timing this week after I do all the other stuff.

Without a testing wheel, how is this done? I can't see doing it (safely) on a moving boat. Can you run a prop in a barrel at WOT?
 

Randyg123

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Re: 1975 135HP Johnson Carb Linkage

Thanks for the link. I didn't think to search the FAQs.

I don't have a 4-station spark tester. Can I just ground out the plugs against the block when I do this, or should I make a tester (I think I saw a post on how to make one somewhere!)?

Is that method accurate or is it just to get you close enough?
 

wavrider

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Nov 26, 2007
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Re: 1975 135HP Johnson Carb Linkage

Ground out #2, #3, and #4, get a spark tester at any auto parts store, around $8 ans hook it to number 1 and ground the other side, connect your inductive timing light to number 1 and follow joe reeves WOT procedures, works fantastic.
 

Randyg123

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Re: 1975 135HP Johnson Carb Linkage

Ground out #2, #3, and #4, get a spark tester at any auto parts store, around $8 ans hook it to number 1 and ground the other side, connect your inductive timing light to number 1 and follow joe reeves WOT procedures, works fantastic.

Well, I am batting about 100 hundred with this motor.
I did as instructed and found that my current setting was around 18-19 (+ the 4 factor = 22-23). So i went to retard the timing to 16 (equals 20 per manual) but I ran out of adjustment possibilities and could not change the timing much. got it down about two units to around 18. so now my timing is theoretically set at 22 degrees. This is still two degrees advanced past what it should be. Would it even run when set 4 degrees past the recommended setting as it was? Before I started messing with this motor it ran fine on the upper end, I just had major starting and idling issues. Another clue: When trying to do a linc and sync following the manual last week, I was looking at the timing on the low end to check and see if it was at 5 degrees to line up my cam. But all I could get was about 0 degrees. Increasing the idle did not change this much but I did not go very high. I don't have a tack so I don't know how high I went up on my rpms but it was quite high (and I did have the motor submerged). I am getting so frustrated with this:(
 

Randyg123

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Apr 20, 2008
Messages
337
Re: 1975 135HP Johnson Carb Linkage

I did as instructed and found that my current setting was around 18-19 (+ the 4 factor = 22-23). So i went to retard the timing to 16 (equals 20 per manual) but I ran out of adjustment possibilities and could not change the timing much. got it down about two units to around 18. so now my timing is theoretically set at 22 degrees. This is still two degrees advanced past what it should be. Would it even run when set 4 degrees past the recommended setting as it was? Before I started messing with this motor it ran fine on the upper end, I just had major starting and idling issues. Another clue: When trying to do a linc and sync following the manual last week, I was looking at the timing on the low end to check and see if it was at 5 degrees to line up my cam. But all I could get was about 0 degrees. Increasing the idle did not change this much but I did not go very high.
:(

Regarding the timing issue, if my values are correct, how would the engine run with the timing set 4-5 degrees advanced?
 
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