Wow some new details and a totally different angle to look for.

Yes, I've been referring to the stock carb for my '86

I have to go out and take another look. When I looked over the choke cable last night it seemed to have a long threaded shaft to secure the cable in it's mounting bracket and just 2 steel flat nuts for adjusting the cables mounting position.

In reference to the spring on the high idle cam in the area of the carb where the cabled choke connects... it's in place and working correctly because the carb will automatically move to high idle (what the spring controls) as I close the choke, and I had actuated those components prior to reinstalling it the first time, and all is working as it should be there. This spring loaded assembly might also allow for the choke plate to open under high vacumn conditions, maybe it's a dual purpose design?

For all the others who did fix this with cable nut adjustment I'm hoping that's all I need to deal with. Guess I need to get out to the garage and recheck everything we talked about.

I'm just really happy today because the carb job is essentially done. I was having some overflow conditions when parked, nothing real bad until the first ride this spring and when I pulled into the garage and shut her down then I had gas pouring out of the overflow ... So I knew that I had to rebuild it and dreaded all the issues you run into with any carb situation. Honestly the overhaul kit, which was more of a universal fit kit did not impress me. The float valve was mainly what I was looking at to change and the replacement was just a bit different and it wanted to stick in the seat and not allow any gas into the bowl. I actually have had it off a total of 6 times since Sunday adjusting the float and wound up with the original valve back in it and working perfect. I think the only issue was a mis-adjusted float. Everything else about the carb is in great shape!

Once again I want to tell all of you that I really appreciate your advice and suggestions!!!

 

Yes, the "threaded" part is the actual housing of the cable assembly that is not covered with plastic coating. The choke plate shaft has a tab that rides on the cam plate. Fast idle is accomplished manually when the cable is pulled. It moves the cam plate against the idle adjustment screw. The choke plate/rod is moved by the tension from round spring because the eccentric of the plate is smaller in that direction and the tab mounted on the choke shaft rides against it there. The eccentric pushes the tab in a direction to force the plate open in the "choke open" position of the cable. If the round spring is broken, the plate will partially close in cable out position via gravity, but opens immediately when vacuum is created by the intake and "fast idle" still happens.

There really isn't any spring tension that pulls the cable closed on that carb (CV is different) so it has to be vibration walking it back in... just look at it all again and hopefully this will all make sense If all else fails, pull the cable off (which is easy on that bike) pull the cable totally out of the housing and wipe it clean (no oil). Put it back into the housing and flex it a little to make a slight "S" bend then re-install.

For all those reading this thread who DO have a CV carb, remember the outer, thin, knurled nut just behind the **** is what actually adjusts the drag. If it's tightened all it will go with finger pressure and the hex nut is snug on the backside and it still walks in, the cable has to be replaced. That's a common and predictable problem with them. Also, never oil the cable on a CV enricher.

 

I understand what you're telling me but in fact the cable walks itself "out" and engages the choke while riding and brings it to the point of the chokes high idle cam engaging. From what I understand, of what you told me, the choke plate opens under high vacuum which is anything faster than an idle. So other than it winding up on high idle with the choke cable easing itself out (closing the choke plate) that choke plate is opening under high vacuum.

I have to get some work clothes on and go out and check all this out right away.

That "drag" in the cable is the important factor, or it will freely move and reposition itself when riding.

I may be dealing with a situation of already having a damaged choke cable.

 

I'll mention this since no one else did. It's really not a good idea to ride an Evo with the choke on for two reasons. The first is the choke (an enricher really) bypasses the idle circuit by dumping raw fuel into the intake manifold. Sitting still while warming up with the choke on for a minute is all right, but longer than that, and especially if you ride with the choke on you are dumping massive amounts of fuel not correctly mixed with air into your cylinders. You're getting the raw fuel from the enricher circuit, the fuel/air mixture from the high speed circuit, plus every time you twist the throttle the accelerator pump is dumping in even more fuel! If your oil rings aren't absolutely perfect (and none of them are for very long) any fuel that gets by them will wash the oil clean off your cylinder walls. Also, and more immediately noticeable, this very rich fuel mixture will eventually foul your spark plugs.

The second thing is more Evo specific. Riding without properly warming up the motor is just asking for both base and head gasket problems down the line. And we Evo guys have a problem as unless you ride with an Evo-centric group most of your buddies will have Twin Cams motors with EFI. They can start a cold motor and go without stumbling as the EFI adjusts everything to the condition of the motor. It makes them think they don't need to warm up (although in reality they should) and leaving you to ride with the choke on or just stumbling and bumbling along behind them (and that's hard on a cold Evo!) Whenever I've been somewhere all day with a group like that I try to anticipate leaving so I can go out and warm up my bike.

Other than that unless someone is shooting at me I'll start my cold Evo using the choke, but only leave it on long enough to be able to keep it running using throttle only. Usually about 20-30 seconds depending on outside air temperature. And I wait until the cylinder heads are warm to the touch before riding. Keep in mind this is a two cylinder motor (that works hard) not your Granddad's 1950s 8-cylinder Buick, LOL!

 

Good post NickD but again, he has a different type carb

OK, I wasn't paying attention obviously... cable walks out! Hmmm Check your throttle cables. They get used to a certain position and when disturbed will often bind.. and it doesn't take much stiff to cause a lot of problems. Also, make sure the return cable isn't too tight at the abutment adjustment on the handlebar end. If it doesn't have some slack there, they will fast idle from binding and the throttle not returning to fully closed position.

You got me a little bluffed with the cable walking out... but I'm late for work and will gone a few days. I'll look forward to your finding when I get back.

PS on the final adjustment of the choke cable position and on the butterfly style carb only, it's a good idea to have about 1/8 of the cable showing on the **** end (sticking out of the housing) so you are assured the choke is in fully off position when **** is pushed in far as it will go. Good luck!

 

If your mixture is close with the kehin butterfly carbs and the carb linkage/butterfly/shaft are in good shape, it should idle with the choke pushed in to the last spot. This spot is basically just a little choke and the fast idle position. Too often people have the idle set low so that the bike sounds cool, consequently when engine is cold it will not stay running on the "fast idle".

 

John, and others, Thanks for your time.

It's good to know all of these details but my issue is more simple mechanics the choke cable, the end with the **** on it, slips outward, putting the choke on, all by itself when I do any rapid acceleration. There's nothing else wrong about the carb or it's ability to run. The bike performs really well right now.

This issue does however mean that there is a richer mixure when this occurs but I haven't been out traveling miles with this issue, just started since I have taken the carb off and put it on so many times.

Oddly enough while out for a cruise just an hour ago I ran into the one guy in my area who is an independent Harley repair and re-builder specializing in EVOs and owns an '86 similar to mine. He set my float for me yesterday seeing as how I didn't quite get it right after a few tries I ran over to his garage and he "eye balled" it to a perfect setting. Now I know how to get it right too.

So, I explained to him the issue and he said to simply crimp the inside cable along with the shielding just enough to have some retention when it's slid all the way in, and supposed to be holding the choke off.

 

NickD is spot on about the EVO's warm up, and enrichner. I start mine on the enrichner full out, and let it run about 10 seconds before pushing it all the way in. At the same time I set the throttle lock to hold a medium idle speed to warm her up. I let mine warm up until the rocker boxes are starting to get pretty warm before riding off slowly to finish the warm up. I only have 28,000 miles on mine so far, but I have yet to have an oil seep anywhere yet. I did a 200 mile round trip today, and she ran so sweet all the way.

 

I took my crimp tool and put a couple of "pinches" in the shield of the choke cable and then went for a hundred mile ride with the wife last evening. The choke never budged. The cable crimp (very small kink) holds the cable just enough so it doesn't slide out when accelerating hard, and creating a condition where the cable had been moving on it's own, setting the choke on, on it's own.

That's the best solution I came up with. I can only guess that there must be other choke cable designs that do have the jam nut that controls the drag.

Have to keep in mind 'Ole '86er is now 25 years old and sometimes odd things happen to older bikes and the fix can be different than typical. You just have to use some ingenuity at times.

 

Glad you got her fixed JohnnyC; Some times you just have to be a little creative when working on old iron. I learned a lot of creative ways to fix things on my 1942 "45" back in the 50's. I had no money so I learned a lot of things that have stuck with me. It is amazing what you can come up with for cheap.