VM26SS sync questions

motomisfit wrote:

Yeah, something is going on in that #1 carb. I’m pretty sure it’s anything in the ignition because #4 plug is fine. It’s looking like I’ll have to pull the carbs and go thru them again. I never thought to check the needles out of round. Thx

Before pulling the carbs again swop plug leads 1 & 4 if the are long enough.
If the issue remains on the same cylinder then it's likely carbs or valve seals. If it moves with the lead it could be ht to coil connection or ht to cap connection or any of the single components. A weak spark will cause a sooty plug. 
On the thread I copied the picture from it was only plug three that was breaking down. It turned out to be a dry contact between the coil 'pin' on number 3 and the ht lead. This was on a coil that had sealed in ht leads. 

I put the choke rod back in #1 and in moving the choke lever up and down, I noticed that the rod wasn’t  going down all way on #1. Just a wee bit, but I can hear a little click and it definitely goes down. I’m having a hard time thinking this could cause the plug being that sooty, but I’m going out for a test ride now. 

Warren, good thoughts on the leads. Off idle, the bike runs strong. And as I mentioned, my top end is new.

The two little arms that lift the white bobbin to open the enricher circuit and put it down to close it are made of fairly soft metal and are easily bent through years of lifting the choke plunger. Are the arms at the same angle as the other three?
Also the plunger shaft is spring loaded to fully close it. Possible dirty/sticky or broken spring maybe? 

The arms are all pretty much the same in how they lift and drop. 2, 3 and 4 plungers seat all the way down. It’s just the #1 plunger that I have to nudge down and at that, it’s just a wee bit. The spring is doing it’s job. All was very clean in there and with it pushed all the way down now, it seems to idle better.

I edited my previous post. I just gave it a nice ride and it DOES pop and spit every once in a while out of 1. Not on acceleration but at a steady rpm. Very slight but definitely there. I’ll try the 1-4 plug wire lead swap next.

Swapped 1&4 leads, no change. Still a little pop out of #1 carb.

Sounds lean if it’s got a pop. Generally caused by hard/worn carb holder boots. Pull all plugs and look to see what each cylinder and piston looks like. 

What plugs are you running?

Carb holders all new. Very sure it’s not a vacuum leak. B8ES. Plugs 2, 3 and 4 are a little sootier than ideal but I’m running 117.5 mains and may have to go to go back to the stock 115’s. 

On my ride today I got on it pretty hard and holy sheepshit, this bike is fast. It pulls strong and hard with no hesitation. Been a while since I rode this bike hard.

Im eliminating the top end as a problem. Something in the #1carb I’m hoping to find as a problem 

Where are the pilot air screws? Angled into the carb Venturi? Or behind float bowls? Finding out that 2,3,&4 are sooty also changes the story some, could be loading up while idling. You can go one heat range hotter to a B7ES

Air screws are angled on the side and right around 1 turn out. Plugs 2, 3 and 4 are a little sooty, but not bad. Another thing, this motor cranks for a very long time before it fires. Once warm, instant start. I haven’t checked actual compression with my gauge, but I did the finger test before I first started it up. Once running, it runs solid. No smoke at all. Doesn’t seem to be running rich at all.

I got my 4 gauge kit so I’m going to work the syncing of the carbs, but I don’t think that’s my problem. At what rpm do you do the testing at?

You really should adjust pilots to get best idle. Holding them the same across all carbs is not best practice. Those are air pilots, turning in will richen, out will lean. Adjust them small increments at a time till you get best idle, set idle adjustment screw till 800-1000 rpm. Then vacuum sync. Adjusting idle speed as carbs smooth out. No higher thans 1200 rpm during sync. 

EDIT; Have you tested coil primary voltage? Extended cranking time could indicate low voltage to coils.

Thanks for hangin in there with me Mikaw. All 4 air pilots are working as they should. Out too much, idle drops. In too much, idle drops.

My little pops every now and then are from the carb itself, not really the exhaust. I have an infrared temp meter and after my ride today, all 4 pipes were within a few degrees of each other. A good thing.

I have not checked coil voltage. Is that at the plug end or voltage to the coil itself? One of my ‘on the list’ things to do is to go to the Dyna S electronic ignition. Ive been told that is a worthwhile upgrade. Is the Dyna system still the way to go? Thx again

Dyna is a good system.  I have it on my Z1B and on my KZ1000.  Mikaw mentioned checking voltage on the primary side, which is where your points plug into the coils.