CD-11 slow speed adjustment

[skanders01]

One of the CD-11’s I am working on will start and run OK and medium and high speeds but will not idle. I am going to get a tach to verify RPM at issue. One item I have a question on is at what RPM should the low speed adjustment make a difference? When I ran it yesterday at what was the minimum speed at which it would stay running (which I estimate to be in the idle to mid speed range) adjusting the slow speed valve made no difference.

Engine will start, as mentioned, but takes several pulls and some choke/throttle adjustments and sweet talk to do so. Having similar issues with starting and idling on the other two DC-11’s I rebuilt.

I again need to lean on the collective expertise of the generous advice giving folks who are members of the group.

Here is a picture of the maiden not so successful voyage. They all ran in a barrel before I started out on this "burn-in under load" trip to open water. Could not get them all to run at one time, and although a wide and slow moving body of water, the lower Fox River, was not a good place to fight a trio of hard starting, poor running fresh (amateur) rebuilts!

Also the maiden voyage of the Alumacraft FD-6 that was restored along with and specifically for the little CD’s. At least the boat test went OK….it didn’t sink!

Thanks for any motor issue advice.

Regards,

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Attachments:

Kyle Anderson
Trempeleau, WI
skanders@triwest.net
920-764-0501

[lindy46]

Interesting set-up – 3 motors on one boat! What have you done to the carb? Has it been taken apart and "rebuilt" with a new kit? If turning the slow speed needle makes no difference in the idle, you need to check the needle tip/orifice. Tip could be broken off in the orifice. You’ll need to remove the welch plug on top of the carb to check the orifice.

[outbdnut2]

Just curious about the three motor setup. Are you using pressure tanks or have you added fuel pumps? Have you linked them all to one tank? If so and it’s a pressure tank, did you get by with just putting all the lines in parallel? I’ve got a boat I’m thinking of rigging for two 1958 10 HP QDs, but once rigged, I also have two 1956 15 Evinrudes I acquired a month ago that I need to get running when time permits.
Dave

[chris-p]

Well it looks cool!

Pretty odd that all 3 start/idle poorly after a rebuild. I could see if you had a bad apple, maybe 2, but all 3?

Bad gas?

Im assuming the SPARK/COMPRESSION is fine on them right?

[Mumbles]

Worn throttle shafts or their bushing area on the carbs will let an air leak into the carb causing an erratic or rough idle. This issue is often missed and the poor running blamed on electrical or other areas. Don’t despair, if the carb is worn, it can be repaired.

Nice job on the triples to. They look great sitting on that boat! 😎

[garry-in-michigan]

Triples are really cool –

I had to do these with PhotoShop. . . 😆

[skanders01]

Thanks very much for the expeditious advice and the compliments, they are all very much appreciated.

Here goes with some answers to the posted questions…

..Carbs were all disassembled, cleaned, and reassembled with new kits. Bear in mind that this was my first go at it. I did nothing with the Welch plugs…guess I am about to learn about them…
..

I ran circular manifolds for air and gas around my restored tank, and "T"eed of branches for each of the three motors. Manifolds gave a more equal supply/pressue drop for the fuel and air to each motor. I am awaiting a tach as mentioned to verify all will run concurrently at max rpm without being starve for gas. They all ran together briefly at a pretty high speed in my test pond. Don’t think manifolding these three little guys will be an issue.
..Gas was not 100% fresh. I will use what I have left in my Echo string trimmer (16:1) and fill the tank fresh before any more trials.
..I was hoping to burn the new rings in under load for a few hours to recheck compression. I never did get a new reliable compression gauge…will now just a little sooner than I had intended.
..Indeed of note, Chris, that all three are hard starters and poor or "non"idlers. It would be great if there were one common problem, but more likely multiple issues. Seems like from what I read, good idling is the toughest thing to achieve. Ironically, two of the motors started up and idled quite nicely in a barrel right after I bought them, and then I started dissecting.
..Even with all new ignition parts (except some coils were ok), the spark seemed just "OK". Again, hoping for no good reason that the spark would improve with some run time.
..Very interesting suggestion, Mumbles. I will check this out. Any good way of identifying the problem? Mic measurements?

Again, thanks for the help. I have enough to keep me busy for a while again now.

Another couple of closer pictures. Aesthetics are at least an accomplishment, mechanicals will continue in progress. I wound up buying a running CD-11 that I am only going to spruce up, and I found another beat up old CD-10 that runs, but plan to use it as parts. Buying stuff at bargain basement prices is addicting. I wonder if there is a 12 step program for this?

Remain open to more input. I may just remove a carb and hire someone with the proper expertise to repair and see if any of the motors come around with a known, properly rebuild carburetor.

WIll update when I finally figure out what issue(s) were.

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Attachments:

Kyle Anderson
Trempeleau, WI
skanders@triwest.net
920-764-0501

[chris-p]

Kyle,

Im still thinking that there is a common denominator here. Perhaps the tank or fuel. DO you have a standard set up tank? Try it on just 1 motor, with fresh fuel mix, and see if one of the poor running motors now runs better. I would not tear into them just yet. These CDs usually idle very well. Something is wrong that is common.

[kevinrude]

What kind of boat is that, Kyle? I am looking for one exactly like that (minus steering deck); one that can handle 3 motors on the transom. Nice rig!

[skanders01]

Chris- I do have a standard tank and good suggestion. I will fill it with clean gas and see what happens. I’m all about trying the easy things first!

Kevinrude- The boat is a 1962 Alumacraft FD-6. Motors are on 14.25" centers and the throttle control cable on the port motor had to be bent to avoid the corner handle, and the starboard motor barely clears its adjacent handle. Actually had to put a spacer (1") on top of the transom to gain the width I needed. Would have liked more width, but raising the transom any more would have compromised the wetted portion of the lower unit. I think the transom width before handle bump up was 35 3/4".

The attached was sent to me by Alumacraft customer service in response to my request to them for model # and year. They were very helpful.

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Attachments:

Kyle Anderson
Trempeleau, WI
skanders@triwest.net
920-764-0501

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