Another carb adjustment question.

DaffyJeffy

DaffyJeffy

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Hi everyone. Around this time last year I posted about a 1959 Johnson CD16 that I was restoring. Had a bunch of trouble getting the fuel pump conversion to work properly. Anyway I needed to get my boat on the water so I ended up putting the power head from a 1968 Johnson CD25R 6hp onto my 5.5 resto project. I got that motor for free because the lower unit was junk. It got me on the water and ran good. So right now I have this Frankenstein situation and honestly I may keep it that way unless I can find a cheap CD16 somewhere and return to that restoration project.

So I'm about ready to get my little fishing boat in the water again and have a few questions: I noticed quite a bit of carbon around the exhast area of the motor (see pic) and I pulled the plugs out today. Take a look at my pics. Do you think I'm running too rich? I cannot honestly remember the gas mix ratio I used - probably 32:1 although I see some literature says 24:1. When I rebuilt the carburetor, I set the adjustment needle to what the literature in the carb kit said (can't remember if it was backed out one turn...something like that). But I plead ignorance here; how is one to adjust that needle (single adjustable needle carb)? How do my spark plugs look? I really don't have a ton of experience with 2 strokes. Any input would be helpful and I really appreciate all the help I received last spring as well.
 

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Willyclay

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racerone

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Check the thermostat.------And does spark jump a gap of 5/16" on both leads ?
 
DaffyJeffy

DaffyJeffy

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Willyclay, appreciate those links thank you. You sure bout the mix ratio? Most of what I've read indicates 32:1.

Racerone, I put a new thermostat in...heck I put nearly everything new in, lol. spark plugs were new and I'm sure I checked the gap when I installed them.
 
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Willyclay

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racerone

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So does spark jump a gap of 5/16" , yes or no ?------An important test to check the health / condition of the magneto.-----Sparkplugs are not used when doing that test.
 
DaffyJeffy

DaffyJeffy

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Racerone, I rebuilt the mag plate myself - new coils, condensers, points, wires....the works. I also meticulously gaped everything and set the timing with a multimeter. Not an ignition problem. Like I said, I'm mainly looking for feedback on how my plugs look as I lack experience reading 2 stroke plugs.
 
DaffyJeffy

DaffyJeffy

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jimmbo said:
Why? The recommended ratio is 50:1.
Click to expand...

Read Willy's comment above and attached link...makes sense to err on the side of caution to me. Oil has changed over the years (TWC-2, TWC-3 etc). When this motor was manufactured (1968) the mix was 32:1. But oil was different then. Products change, recommendations change.
 
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JerEazy

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DaffyJeffy said:
I'm mainly looking for feedback on how my plugs look as I lack experience reading 2 stroke plugs.
Click to expand...

I've seen worse - looks like there is some oil build-up. so you MIGHT be running with too much oil. replace and run a tank of 40:1 and see what they look like.
 
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racerone

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Since 1964 the mix on OMC motors has been 50:1 and not 32:1---------That 1968 motor will run just fine on 50:1 mix.----40:1 is more oil than needed.----But that will keep mosquitos off the lake while trolling.
 
DaffyJeffy

DaffyJeffy

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racerone said:
Since 1964 the mix on OMC motors has been 50:1 and not 32:1---------That 1968 motor will run just fine on 50:1 mix.----40:1 is more oil than needed.----But that will keep mosquitos off the lake while trolling.
Click to expand...

To quote Chinewalker " I've found that the smaller (3, 4, 5, 6hp) motors from post 1964 up into the mid-1970s may appreciate a bit of extra oil as they still have some bronze sleeve bearings."

And it depends on source and when that source was written. Here is a page from an official Johnson/OMC service manual:
 

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racerone

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Why the confusion ?-----The 1968 model 6 HP runs on 50:1 mix !!-----The bronze bushings main bearings on the 6 HP models were very well thought out / engineered.---The connecting rod big end are needle bearings.----I have taken more than one apart.-------Main bushings never show any signs of wear.at 50:1 and often look like new.
 
DaffyJeffy

DaffyJeffy

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racerone said:
Why the confusion ?-----The 1968 model 6 HP runs on 50:1 mix !!-----The bronze bushings main bearings on the 6 HP models were very well thought out / engineered.---The connecting rod big end are needle bearings.----I have taken more than one apart.-------Main bushings never show any signs of wear.at 50:1 and often look like new.
Click to expand...

Well, I guess take that quibble up with Chinewalker. I'm just trying to learn.
 
jimmbo

jimmbo

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DaffyJeffy said:
To quote Chinewalker " I've found that the smaller (3, 4, 5, 6hp) motors from post 1964 up into the mid-1970s may appreciate a bit of extra oil as they still have some bronze sleeve bearings."

And it depends on source and when that source was written. Here is a page from an official Johnson/OMC service manual:
Click to expand...

Here's another source, the 1964 sales brochure

http://boatinfo.no/lib/johnson/broch...hnson.html#/18

I wish I still had the owners manual for our 1964 5.5, It said 50:1 except for the 10 hr Break In period, which was 24:1
 
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