carb balancing with YICS eliminator question

Alright... I'm trying to get the project finished up, for the most part, here in the next few weeks. I installed the YICS eliminator tool today and was going to see if I could get the carbs balanced. Have any of you had success with doing it this way? I know I need to adjust the idle screw when the YICS tool is installed, but I had to adjust mine ALL the way in and was still having trouble getting the bike to idle. I haven't had it running for a month or so, so if I have no luck again tomorrow I may remove the tool and attempt to get it idling again without it.

I'm just looking for any advice or wisdom on this subject. I want to get this thing balanced and tuned up, so I can check that off of the list and move on to the other items....

Back out to the garage now to get the signals installed and maybe some other wiring wrapped up while I'm at it.

 

Have you had the carbs out for a cleaning? Turning the idle screw all the way in I would say the idle circuit is cloged on one or more of the carbs. Tell us what if anything thats been done on the carbs. Is all the other things in order, plugs, airfilter, valve adjustments.

 

yeah, I cleaned the shit out of the carbs and replaced all of the seals. I had it running pretty good, but when I synched the carbs I didn't have the YICS tool yet. I was just trying to resynch with the YICS eliminator and wasn't having the greatest time trying.

 

I find it's best to 1) make sure the slides pass a clunk test so that you can 2) get really damn close using the bb drop bench sync method. That way all the adjustments made with the YICS blocker in are for sure TINY adjustments. Any large adjustments needed and you know something else is wonky. You'll get as many "one true methods" as guys ya ask. That's just mine.

 

I guess I didn't give enough info....

These carbs have been cleaned/rebuilt, bench synched, synched with carb synch tool on the bike, and the bike idled and ran well with the stock exhaust.

Since then I the bike has set for a month or so and I hacked off the original exhaust, painted the header with VHT header paint and wrapped them, and installed Screamin Eagle pipes AFTER the collector. Since the collector is still in the system I didn't think I would have any problems. The bike was running well before this.

I am not using the gas tank at the moment. I am using a reserve bottle I have hanging from the handlebar that looks like my bike is hooked up to an IV.

Also, when I had the carbs synched before the idle screw was pretty far out, giving me plenty of room for adjustment.

Now, with all that info..... advice?

I am going to go out later this morning/ early afternoon and give her another go.

 

Here's an idea- - Ethanol in the fuel got you !
Your bike ran at least OK a month ago.
Using the full length of the idle adjust screw/rod would give about a 7,000 RPM idle.
Did you throw water on your exhaust to see which is the dead CYL?
You can carefully remove the Pilot needle/spring/washer/O ring, then blast carb cleaner directly down the Pilot well, hopefully de-gumming that Pilot circuit WITHOUT removing the carb rack.
Only do the "bad" carbs.

Then get back to tuning.

 

Strange one, I don't think the exhaust mods have affected the idle. It might affect the midrange throttle. Do you have spark on all 4 plugs? I would pull the carbs again to re-bench sync and blow out the idle circuit with compressed air and set the mixture screws to 2 1/2 turns. Put them back on and go drom there.

 

The fuel was just out of my can I use to fill my mower, so could that be part of it? Old gas?

Dead Cylinder? Do I have one of those... hahahaha No I didn't do this. I couldn't even get it to stay running for more than 2-3 seconds.

Oh, and I think my floats are stuck right now or something too, because gas was pouring out of my overflow whenever I turned it on. I had to just turn it on a bit to fill the bowls and then shut it off.

I DID have spark on all 4, but I didn't check it yesterday. When it would run for 2-3 seconds here and there it didn't sound all jacked up or missing or anything like I was only firing on 2-3 cylinders.

I was REALLY trying to avoid pulling the carbs again

 

You've got to fix the floats and set them to the correct level (clear tube) or it'll never work right.

The wrap will most definately effect the exhaust flow and thus the mix settings. It holds heat in the pipe and hot gasses flow faster. How much depends on the rest of your exhaust.

The rest is not what you want to hear but is the right answer.....

You have to start over on your tuning with the changes you've made. Pull the carbs, fix the float level, bench sync again with the 3x5 card or whatever method you like, set pilots at 2.5 turns out then reinstall and fire it up. Adjust synch and idle mix then with the engine good and hot.

 

With the floats hanging its time to pull the carbs again.

 

The floats hung the last time I installed them until I fired it up and then they settled in place and no more leaking. I was hoping to have that happen again.

 

that shouldn't happen.

Try tapping the bottom of them with a hammer handle when filling.

 

A month of sitting is long enough to require another carb cleaning!

 

Clean again after a month ?? because..they weren't done properly, no fuel filter, water in th fuel, sabotage, somehow got gunk in when re assembling, I don gettit. Over a year since mine were done and no problems. As they say do it right th first time.

 

I don't think I need to clean the carbs. The bike is sitting in my garage, I did a good job the first go around, and I have a fuel and filter, so I'm leaving them alone for now.

I haven't messed with it since the other day, because I've had a killer sinus headache that won't go away. I worked 12 hours last night and work tonight again from 7pm-7am, so I'll take a look at it again tomorrow or Friday and if I can't get it to idle right away I'm just going to pull the YICS eliminator and see if I have any better luck.

Hopefully this shitty rain will clear up, so I can get the bike running and take it for a spin. If not I'll put off fiddleing with the motor and get back to work on the wiring. I need to run the wires for the headlight, signals, and tail light. Not my favorite thing to do, but I already got the rear signals mounted and the front mounts slightly modified, painted, and ready to install and I tested them out and they all work.

 

Yeah, I never would have thought you'd need to do the carbs again, but I'll tell ya, I've been reading some real horror stories about ethanol-blended fuel going south after VERY short periods of time.

Guys on other forums have reported ethanol-blend gas turning after a month to what "normal" gas may look like after a year...

I don't have any first-hand experience with it. We have 10~15% ethanol in all gasoline in Florida now, but I've not had a bike that has sat for any length of time with it. We'll see...

 

Back to the original description of the problem, though:

You say you had to run the idle mixture screws all the way in and it still wouldn't idle.

As I understand it, running the screws in make the idle mixture leaner and leaner. So, from that, you must've been running very very rich.

And that ties back in with floats and the symptom of carbs overflowing. Carbs overflowing (for whatever reason) certainly lead to rich idle mixture.

Turning the fuel supply on and off may indeed aleviate the flooding, but it just makes the tuning that much more impossible - you never know where to set the mixture screws. That is, set 'em for the moments when the fuel level is high, or set 'em for the moments when the level is lower? Back and forth...

I'd try and solve the fuel level problem first - tapping on the sides can free up sticky floats. Had that happen many many times.

Good luck with it.

Kirk

 

Just a side note- - my perfectly running 750 went down for 5 months due to electrical failures. March to July, in a shed. The carb jets were gummed up solid. They may have been gummed up by 2 months.

 

NO, I didn't touch the mixture screws. I just tweaked the idle adjustment/screw. that's it.

 

"THE" idle adjustment screw?

There are three of them; plus the big main adjuster knob.

Using some form of manometer (vacuum gauge/meter) you adjust carbs 1 and 2 to each other then match them to #3. Then match 4 to 3 (or match 4 to 3 first, it matters not.) #3 is the "base" it has no adjuster other than the main knob.

You do this (the running vacuum sync) with the YICS blocked off; but your YICS-blocking tool has to be working properly. The "YICS eliminator" is NOT the proper tool for the job.

You never touched the mixture screws? How about when you cleaned the carbs? No? Then the carbs aren't truly clean...

 

we're just having a misunderstanding of terms. I'm calling the big thumbwheel dealio the idle adjuster. I didn't touch the other three THIS time...

I thought I made it clear that I had cleaned the carbs, bench synched (where I adjusted everything to get it close enough to synch with a gauge on the bike while running), then I synched the carbs on the bike with a manometer, but this was before I had the YICS eliminator tool. It was running decent and idling just fine, but since I'm getting everything all put back together I wanted the bike running GREAT before putting the tank on and wrapping it all up, so I was going to attempt to dial it in a bit better. I didn't even bother firing it up and getting it to idle without the YICS tool in place, because it ran good the last time I started it.

This is where we are at now....

The carbs should still be synched enough to idle, but with the tool in I couldn't get it to stay running. I was sick with sinus shit, so I haven't messed with it and tomorrow is my 11th anniversary, so STILL not sure when I'll go out and give it another go, but hopefully Sunday or Monday at the latest.

So, looking back at your message above.... when I said I didn't touch the mixture screws I just meant THIS time after previously bench synching and synching the carbs without the YICS eliminator tool.

Does this make more sense now? Let me know if it's still only clear as mud.

 

take your tool out, then get it to idle, let it get warmed up, check the floats and for vacuum leaks then even if you did it before do a sync running get the mixture dialed in around 2 3/4 out
now your close, put the tool in and do the sync again then the mixture
back and forth a few times till your happy with it then take the tool out
thats all i'll say now except that i don't have a tool

 

yeah, that's the plan..... now i just need to get it to idle. That was kind of the whole issue here in the first place.

 

It will idle like a sewing machine once properly sync'ed.

Polock's procedure is pretty spot on.

Without trying to start the whole "why you don't need a YICS tool" debate over again, I will say this:

The YICS system will "mask" an out-of-balance condition enough that the manometer will indicate that you are in balance when you're not. With a correctly-configured YICS tool in place, the imbalance cannot "hide" and will be revealed.

The debate starts because once in balance WITH the tool in place, they will also show as balanced with the tool out. However, if balanced without the YICS being blocked, they may not actually be balanced, and you won't be able to tell.

I'm not just guessing or making stuff up, I did quite a bit of experimenting with balance (using a Morgan Carbtune) with the YICS tool in and out.

Of course, it has to be a proper YICS tool. The "eliminator" thing off eBay isn't one.

 

Ok, today I finally got around to popping the YICS eliminator back out and trying to get the bike to start and idle. Well, I could only get it to stay running for a max of 2-3 seconds before, but today I got that up to about 10 seconds. Small victory, right?

I could get it to idle for a few and rpm's would increase if I was light on the throttle, but then it was unresponsive no matter how much I would twist the throttle and nothing I did would keep it going. It just bogs down and then sputters out.

I also still have fuel pouring out of the tube connected to the air box if I turn the fuel valve on my aux tank for more than like 3 seconds.

 

Did you do anything with the floats?

You're probably pouring liquid fuel into the cylinders as well as out that hose. liquid gasoline does not burn and will flood the cylinders.

Address the floats. Height correct and shutting off. Then try again.

 

Yeah, the last time they were doing that I just got it running and took it for a spin and everything settled. I was hoping it would do the same this time.

I'm one step closer. With a little choke and a little throttle I can get it to idle just fine, but if I let up on either of them it sputters out.

 

turn the middle Idle speed screw (the big one between #2 and #3) about a turn IN. That'll open your blades up a bit and help it. You also may need to turn your mix screws out 1/4 to 1/2 turn to get rid of the choke.

If you didn't let the bike warm up then forget what I said above and warm it up first. Then try what I said.

 

I think I just need to bite the bullet and pull the carbs. Clean them a bit AGAIN and bench synch them.... AGAIN! because messing with the middle idle speed screw, which I did earlier, had absolutely no affect on the idle

CRAP...guess I know what I'm doing tonight after the wife goes to bed. f'n pain in my ass.

 

The carbs or the wife?

I know it's a PITA but you gotta do it.

 

the wife has actually been pretty cool lately.

The carbs.... I'm going to bet that I get tired and lazy later and don't actually touch them... any takers on that one?