Plugs fouling

[davomoto]

Rob,

Make sure slides are synced. if not, you will get a hanging idle!!!

Davo

[Snakeoil]

Thanks, Davo. I did check but will recheck when I reset the floats. I must admit that I never knew that a hanging idle was a symptom of slides out of sync.

Regards,
Rob

[mike in idaho]

Have you checked the compression lately? Last time I had to deal with hanging idle on a Honda scrambler, it had some broken rings in one cylinder. Do you have one idle stop screw in farther than the other one, to get an even idle? Does it puff smoke out of that side when you rev it off idle?

[davomoto]

Yes, it's usually slides or an air leak. A too tight intake valve will cause a lean condition as well.

Davo

[Snakeoil]

My CB77 carb kits arrived today from Retrobike. Terry sent them via Priority Mail at my request. Cannot thank them enough for being so responsive.

Per LM's recommendations in our conversation last week, I ordered 2 CB77 carb kits to install in my CL77 carbs. To summarize, he said he's never seen a CL not run better with the CB jets and needles.

The kids are Keysters, and although I've heard folks gripe about their quality, I found them to be excellent. It came will new jets (42/135) new CB D9 Needle, new float valve and seat, new throttle stop,new idle air screw, 2 new springs for the screws, float bowl gasket, circlip for the needle, spring keeper for the needle in the slide new top rubber gasket and misc gaskets for the banjos and float valve, new carb o-ring and air screw o-ring.

Only part in the kit that I felt was not "right" was the spring keeper for the needle in the slide. Much thicker and stiffer than the original. Too thick and still IMHO.

I did not replace everything. My float needle did not leak and my stop and idle screws are fine. I replaced only the pilot and main jets and the needle. I set the needle clip in the second groove from the bottom per LM's recommendations.

Bike fired right up. It popped and farted a bit when it was cold. But once it warmed up, it ran like a raped ape. Took it for a shakedown ride and my only complaint is a small flat spot if you back off and then roll the throttle back on. Might have to put the needle clip in the bottom groove. It's very minor so will live with it until the weather warms up a bit.

Knocking on wood here, I'd like to say that it seems my woes and annoyances with the bike are solved. New wires seems to have fixed the running on one cylinder problem. Rejetting with stock CB77 jets has made it less cold blooded and it runs much better. Idles perfectly.

Of course, the giro is yet to come. It is the first weekend in May. That is when the various problems always seem to appear out of the blue. So, I'm not going to be 100% sure the problems are solved until the giro has come and gone.

Thanks for all who assisted, suggested or supported thru the troubleshooting.

regards,
Rob

[Snakeoil]

Well, the Motogiro has come and gone. There was a point on the morning of the first day where it looked like the bike was not going to let me finish. But I found the problem and it never failed to perform for the rest of the day and thru the rain on the second day.

I think I may have finally found why the bike would intermittently run on 1 cylinder. I won't bore you with all the gory details of pulling into the lunch stop that first day, only to have the bike start to run on 1 cylinder for no reason. Suffice to say that after much aggravation and troubleshooting I actually found the problem by mistake. I had resolved myself that the bike was done and I pulled the plug on the right (dead) cylinder so I could ride the 3 miles back to the hotel where my trailer and tools were. As I fired up the bike to leave, I looked down to make sure the dangling plug lead would not get into trouble on the ride back and I watched what had to be a 3/4" long spark jump from the outer metal case of the plug cap to the head. It turns out that the internal insulation on that original plug cap was failing and shorting out to the outside metal jacket would, which in turn would short to the head. This is why I would have spark at the plug when testing sometimes and other times not. It appears to have not always shorted thru the jacket.

So, I headed back to the hotel on one cylinder and on the way, passed a John Deere dealer. Lights were off and sign said they close at 1pm on Saturday and it was after 1pm. I was cursing and spitting fire and for some reason, tugged on the door and it opened. Place was black inside. I yelled "Anyone still here". and a voice replied, "Who the Hell are you?!!". I came in, explained my problem and that I needed two new plug caps. The guy behind the counter knew the NGK part number by heart. Turns out, he rode bikes, did some racing, and worked in a bike shop for many years. They had exactly what I needed and she fired up and ran perfect on the first kick.

I flew back down the road and back onto the course. I truly rode the bike like I stole it. I was probably at least a half hour behind my assigned departure time, maybe more. I arrived at the next time check, 42 miles later, 9 minutes early.

The bike never missed a beat for the rest of the giro and that included a Sunday morning with driving rain and temps in the 40's at best.

So, I know others here had experienced the same intermittent 1 cylinder operation, even with only 1 carb. I thought replacing the wires had fixed it as the plug caps tested perfectly. But it looks like they both have multiple personality disorder.

I'm still running the original coils and condensers.

I did resynch my carbs as Davo and others suggested and used LM's finger in the bores method. Got them perfect. High idle/lagging high idle issue went away.

I also want to report that my paper gasket fix for the ruptured insulator blocks worked perfect. I think the ruptures were causing air leaks and contributing to my idle being all over the place. The bike idled so smooth I would have to rev it to know it was still running with all the other bikes running around me as we went thru time checks and such.

So, thanks for all the help thru the life of this thread. The running on one jug and crazy idle have plagued this bike since I've owned it. It ran great when the problems did not decide to appear, so I was still happy with the bike. But now, I truly love the little beast.

regards,
Rob

[SWARDLAW]

Great story. I love to read stories of people with a passion for the old bikes. You have that passion. Stories like these prove that you don't need a $30K Harley to have fun riding. Keep riding and smiling.