1968 Johnson 6 hp, first sea trial and need some tuning...little help :)

[clemsparks]

Hey all.

Love the community here.

So, I've got a '68 6 hp Johnson (Model number CD-25C) that I ran in a bucket Yesterday and then put on a johnboat and in the river today. I got this engine a year ago and was told it ran, had had the impeller replaced that year, and that the primary starter wasn't working...so the PO and I have relied on a rope on the flywheel.

Underway, I quickly realized that the engine would only run with almost 100% choke. At one point, it ran good with a little less choke, but as time went on, it steadily ran worse until it would only run with the choke on and it would not put out any power.

Earlier in the evening, it would actually put out some power, but I started messing with the rich/lean knob and it just never recovered.

It was putting water out the hole mid-leg today (but it wouldn't in the bucket yesterday, so I didn't run it long...no more than a minute and it never got so hot I could not touch the powerhead block).

I really don't know much about these neat little engines, but I want to get it tuned up proper so I can get my girls out on the river (Missouri River, so it's kind of imperative I get it right ).

Can anyone help me worth through this and get 'er tuned up right?

I'm pretty sure I probably left out some details you'll need to help me, so I'll preemptively acknowledge that and ask you to go ahead and let me know what info you still need...thanks!

Thanks!
Clem

 

[fireman57]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

The carb needs a good soak and cleaning. Make sure that you blow all the holes out with compressed air. Once you know that it is really clean start it in a trash can full of water so that you have water at least half way up the leg. Just a bucket doesn't help much as the water pump is not self priming and you would have no back pressure like you would on the water. You can set your idle then. Take her out and she should run without the choke on. You can fiddle with your high speed then. You might consider putting a rebuild kit in the carb that will make sure that you have a good float and needle valve.

 

[kfa4303]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Hi Clem. Check out the "awakening a sleeping oputboard" thread in the sticky at the top of the forum and yo'll find all the basic steps you need to get it running again. I agreee with fireman57. Proably just needs a good carb cleaing/rebuild. You can get a rebuild kit right here at iboats for about $20, and there are tons of threads that can walk you through the processs.

 

[clemsparks]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Thanks for the input folks.

I kind of figured since I needed so much choke that I wasn't getting much fuel.

Next step is to remove the carburetor and clean it up. From the parts diagrams, it looks like it is a pretty simple carb, so I will attempt to just disassemble, clean, and reassemble without a rebuild kit...unless I get in there and see that something is obviously needing replaced (like if I tear a gasket or o-ring...which is probably likely).

About the "bucket." It was actually a storage tote like what my sweaters live in during the summer months. But I did some research here which told me that the leg needed to be in the water a fair amount to let the water circulate properly (which makes sense with what was posted above...need more head to help it prime). For testing in the future, I'll just go to the river as it is easier than messing around with barrels and hoses, wasting lots of drinking water, and/or breeding more mosquitos.

I'll get a manual for this eventually, I think...but in the mean time, I'm scrounging .

I've been through the "waking up an outboard" thread a time or two as well.

Thanks for the help!
Clem

 

[1946Zephyr]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

You might also do a spark test on it too and make sure you're getting good spark on both cylinders. A weak coil can actually make one believe that there is a carb issue.

 

[clemsparks]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Looks like this could be part of the problem...

Time for a new (plastic) float! (that's a cork float...cool!)

Clem

 

[kfa4303]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Hi clem. you can get a new carb kit and a new, plastic float right here at iboats. Here are the links to them and a link on how to dial in your carb. Keep us posted. Good luck.

http://forums.iboats.com/showthread.php?t=167352

http://www.iboats.com/Carburetor-Fl...54.1968--**********.832006900--view_id.174136

http://www.iboats.com/mall/partfind...gd_poid=109330&gd_row=14&**********=832006900

 

[clemsparks]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Thanks for the link on the float...that's the one piece I have been unable to find on iboats. Question is...how do we know it's the correct one? When I follow the iboats outboard parts to the listings for floats, my engine does not come up on the list of available floats.

I don't have a manual yet (will probably order one today [edit: just DID order one today]) which may or may not be helpful for this...

Thanks,
Clem

 

[kfa4303]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Hi Clem. Here are some handy links. Use the first link to select which model 6 hp you have and you'll pull up a manual with exploded diagrams and part numbers for your entire motor. The second link is from here at the iboats store. You can type in your hp and/or model year on the right side margin. When I typed in your motor carb float, Sierra part #18-7210 popped up. As you can see from the list, virtually all of the vintage OMC motors use the same replacement float. Double check the original OMC part number for your carb float from the diagrams in the first link to make sure the new float (18-7210) will work.


http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1968&hp=6

http://www.iboats.com/Johnson-Carbu...5312035--**********.188164502--view_id.271386

 

[clemsparks]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Thanks again,

The problem is (and I've been to both of these spots trying to figure this out) that iboats does not list a 6 hp Johnson under their carburetor float options (in the link: http://www.iboats.com/Johnson-Carburetor-Floats/dm/view_id.271386). iboats' selection of floats start at 18 hp engines. Granted...all the listings are the same and I have a strong feelign that you are probably right, and the same float will work for my carburetor/engine. I just don't want to order it without having some confirmation that it will work. Looks like a call to iboats is in order.

I can find the float on marineengine, but it isn't a Sierra part, so I haven't been able to cross reference it thus far.

I'm sure I'll get this figured out today...just a matter of a little extra communiatio with the vendors, I think.

Thanks,
Clem

 

[kfa4303]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

What is the original OMC part number? If you post it I'm sure one of the Gurus will know the modern Sierra equivalent part number. Post your exact model too, so we know what you have going forward. Keep us posted.

 

[clemsparks]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Model number (also listed in first post) is CD-25C.

Judging by the parts breakdown on one of the other sites, the original float part number is/was 0375919.

Thanks again for the help!

Clem

 

[clemsparks]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Well...I went ahead and ordered the float from another vendor (hoping to maybe get it before the weekend).

However, I'm sure if someone can offer clarification (on which Sierra p/n works with a CD-25C Johnson 6 hp from '68), it will be helpful to others who experience this in the future and search the forums.

I DID order my gear housing seal kit from iBoats today, though

Thanks,
Clem

 

[clemsparks]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Thanks again for the help folks. Got it out this evening after a thorough carburetor cleanup and a new float and it ran "ok." Though it really only ran good in the midrange. It doesn't like to idle very low (not even to the "shift" position on the handle) and it has a bit of a miss under full throttle. I assume the latter is due to a lean setting on my high speed adjustment. From the manual, I can't see how to adjust this. I'm new to this carburetor. Looks like there's a "High Speed Nozzle" and upstream from that is the "Orifice Plug."

There is no high speed needle valve that I can find.

And then any advice on getting this to Idle slower would be great. It may be time to look closer at my ignition system (I have admittedly not looked into that at all yet).

Thanks,
Clem

 

[AlTn]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

google..leeroy's ramblings and read his section on 6hp. repair and maintenance...there is no separate high speed adjustable jet on your carb as the orfice plug is your jet < the orfice plug needs to be removed and cleaned as well as the area behind it>...when you rebuilt your carb did you remove the core plug < part no. 30 on the carb diagram at marineengine.com > and clean that area as well as the 3 small holes that enter the carb throat behind the throttle butterfly?...did you replace the packing < parts no. 35 in the idle needle passage > ? what shape is the idle mixture needle in as far as the taper and point ? did you adjust the float so that is level with the carb casting with the carb inverted?
When you get ready to work on the ignition components, post back or use the search feature as there is a wealth of info already discussed on the universal magneto ignition system.

 

[clemsparks]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

Let's see...

Yes, I should reread the ramblings article a few more times.

No, I did not remove the core plug or the high speed orifice...but I did flush well and think I got it very clean (though I'll never know without doing this, I suppose).

Yes, I did replace the packing, #35 (2 pcs) and the old ones seamed to be creating a lot of debris. Seems like a bit of a design flaw to me...fibre packing that can come loose and into the fuel passages...oh well...note to self: Keep an eye on this in the future.

The taper on the slow speed needle looks fine (not corroded, damaged, or undercut).

Yes, the float was level.

Yes, I know how to use a search function on an internet forum. No, I don't like to be told to do that (though I realize you probably weren't criticizing...just trying to be helpful).

Thanks!
Clem

 

[AlTn]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

nope..not criticizing..just didn't know if you'd ever noticed the icon...to my way of thinking, the search feature leaves a lot to be desired ,but I know squat about the mechanisms to build and sustain it..'course it may be I don't know enough to properly ask the questions either

 

[kfa4303]

Re: 1968 Johnson 6 hp, first sea trial and need some tuning...little help

HI clem. This link may help with the carb rebuild, if you need it. It's for a different motor, but the basics are the same.


http://www.outboard-boat-motor-repa...hnson 5.5 HP 1954-1964 Carburetor Tune-UP.htm

http://www.iboats.com/Johnson-Carbu...15.1968--**********.360650333--view_id.271381

http://www.sschapterpsa.com/ramblings/johnson_QD.htm (not exactly the same as your motor, but close)