Carb Help!!

[TADracer]

My brother did the green coils. How would I be able to tell it that resistor is bypassed?

The resistor is located on the frame just above the left side of the valve cover. Simply unplug the wires from the resistor and plug them into themselves. Remove the resistor from the frame or leave it on if you wish.

[Haarstad]

So i checked the little hole in the bottom of the bowls and they were all clean, one had a tiny speck on the side wall but i cleaned them all up anyways and got that speck out of there.

After i finished that i took it for a spin and now it stutters when trying to start moving from the stopped position. I think i need to move the c-clip on the needle down because it did this before and moving the needle down one to the middle position helped.

I just got done checking the pickup coil wires and made sure that the timing advance wasn't frozen and everything is looking good in there, timing advance moves freely and when i move it, there is a sucking sound coming from the carbs(?). It sounds like something is moving up and down, I'm assuming this is a good sign. My brother had already fixed the pickup coil wires last year and i pulled gently and there was no give or hourglass shape so the wires seem to be in good shape.

I haven't checked the gas cap yet but i think everything is alright with that cause i forgot to shut off the petcocks when taking the carbs off last week and as soon as i pulled off a hose, fuel came pouring out. So i think that's good but I'll check it when i check the ballast resistor cause I'm out of ideas so I'm gonna try everything.

I have to go to work soon so i want to relax a bit so I'll try the ballast resistor tomorrow and check the gas tank cap then too. If both of those fail to help. The carbs are going to get ripped apart again for yet another cleaning... I feel like i didn't do a very thorough job since i didn't even clean that hole in the bottom of the bowl until someone mentioned it. I fear that the cleaning won't help though cause the only things that were gummed up when i got the carbs were the main jets and the sides of the bowls a little... While i have the carbs off, I'll try moving the needles down one notch.

If none of this works I'll be stuck in a dilemma again... This bike is just making me frustrated... Nothing i do works...

Thanks for all of your help though, at least we're narrowing it down

[jimbyjimb]

I had a very similar problem with my bike a few months ago when I swapped to Mikes coils. After checking the pickup coil issue/advance issue under member advice I found I had not removed the ballast resistor. All it takes is to whip off the tank and look on the left frame rail. Removal and bypass takes approximately 2 minutes if you're going turtle speed.

Fixed the erratic idle and power issues. It also shook like the dickens at low to mid RPM.

When I first installed the coils, resistor still in the loop, it idled well enough for a sync. Shortly after the idle went nuts.

The resistor is the simplest item to look for.

http://www.ebay.com/itm/80-XS1100-XS...#ht_797wt_1185

That's what it looks like.

[crazy steve]

If you didn't fully disassemble the carbs (everything out of the bodies except the throttle shafts), they're probably still dirty in places...

http://www.xs11.com/forum/showthread.php?t=36017

[James England]

After i finished that i took it for a spin and now it stutters when trying to start moving from the stopped position. I think i need to move the c-clip on the needle dow.

I haven't checked the gas cap yet but i think everything is alright with that cause i forgot to shut off the petcocks when taking the carbs off last week and as soon as i pulled off a hose, fuel came pouring out. So i think that's good

The needle position isn't relevant at low speeds and I'd be wary about just changing things at random without a proper diagnosis. Otherwise you'll just end up not knowing where you are. Moving it last time may have helped but may not cure the problem that's causing it.

Re the gas... yes the gas would come pouring out if the bike has sat for a while unused. It would do that even if the cap is a little bit blocked. With the engine running, that gas would be burned, emptying the float bowls and then fuel starvation kicks in. Leave the bike for a few minutes and the carbs fill up again. So I'd check that cap.

You haven't cleaned the carbs properly by the sound of it. Did you remove the floats, needle valves + seats +little filters, all jets, emulsion tubes, slides+needles+springs, choke assemblies? Did you blow compressed air through all the passageways? Clear the holes in the emulsion tubes? Did you do all that? Somehow, I think you didn't. I think your carbs need a good, proper clean...moving needles a notch and just guessing things will just make it all worse........

[natemoen]

Agreed, leave the needle clip in the center notch. Everyone pretty much ends up putting it back there after messing with it anyways. So just save yourself the hassle and leave it in the middle.

[motoman]

So i checked the little hole in the bottom of the bowls and they were all clean, one had a tiny speck on the side wall but i cleaned them all up anyways and got that speck out of there.

After i finished that i took it for a spin and now it stutters when trying to start moving from the stopped position. I think i need to move the c-clip on the needle down because it did this before and moving the needle down one to the middle position helped.

I just got done checking the pickup coil wires and made sure that the timing advance wasn't frozen and everything is looking good in there, timing advance moves freely and when i move it, there is a sucking sound coming from the carbs(?). It sounds like something is moving up and down, I'm assuming this is a good sign. My brother had already fixed the pickup coil wires last year and i pulled gently and there was no give or hourglass shape so the wires seem to be in good shape.

That sucking sound is NOT the carbs, its the vacuum can(since apparently you didn't remove vacuum can arm from the timing plate when rotating plate back and forth) As Steve stated, if you didn't remove enough stuff from carbs they likely still have restricted places. If you didn't remove the diaphrams and slides so the emulsion tubes can be removed and cleaned, if necessary with a toothpic, no metal allowed AFTER removing the main jets, your pissin in the wind and any other changes made throwing parts at it is gonna just leave you with a cluster and you'll be going WTF. Not insulting you.........we here have seen this TOO many times with other first timer rodeos.

[cywelchjr]

That sucking sound is NOT the carbs, its the vacuum can(since apparently you didn't remove vacuum can arm from the timing plate when rotating plate back and forth) As Steve stated, if you didn't remove enough stuff from carbs they likely still have restricted places. If you didn't remove the diaphrams and slides so the emulsion tubes can be removed and cleaned, if necessary with a toothpic, no metal allowed AFTER removing the main jets, your pissin in the wind and any other changes made throwing parts at it is gonna just leave you with a cluster and you'll be going WTF. Not insulting you.........we here have seen this TOO many times with other first timer rodeos.

+1, if it ran last year, and it's not running well now, and the difference is it sat over the winter, the carbs WILL need a complete cleaning. The only ones of us who get away without doing a yearly cleaning are those who have things properly prepped when storing the bike, or those who's bikes are ridden year round (such as mine and many other Ca members) as the gas never gets a chance to gum up the works.

[motoman]

+1, if it ran last year, and it's not running well now, and the difference is it sat over the winter, the carbs WILL need a complete cleaning. The only ones of us who get away without doing a yearly cleaning are those who have things properly prepped when storing the bike, or those who's bikes are ridden year round (such as mine and many other Ca members) as the gas never gets a chance to gum up the works.

........and here yr.round at my location in Colo...........where we still can get a resemblance of that product called gas, unlike in Cantafordya.

[Haarstad]

OK, i just got done cleaning the carbs again, Cleaned the outside and then took the carbs completely apart and cleaned the inside, i found a couple specs of gunk in a couple spots. After i got everything all cleaned up, i put them back together, put them on the bike, adjusted the mixture screws, re-synced the carbs and took it for a spin.

I still can't go above 5k rpm, however it seems a little more forgiving when trying to go over 3/4 throttle. Instead of completely falling on it's face, it seems like it wants to go. It is cutting out intermittently though when trying to go over 3/4 throttle.

I'm thinking i should check out main jets again since cleaning the carbs again did help a little. Right now i have 140 mains in my '78 carbs and i was thinking maybe i should try 137.5's and if that isn't any better, then try 142.5's

I have to get ready for work but I'll check out whatever you guys think i should next, i just figured I'd throw my opinion out there too

Thanks for the help!

[GLoweVA]

I'm no jetting expert, but I've read these guys on here talk about anything that opens up the intake and exhaust on these machines, you need to open up the jetting too.
You state

I have a 79 XS1100 Special with 78 carbs on it with cheap pods, and 4-1 kerker exhaust.

So with pods and a 4-1, I'd say you definitely need to probably go up on the jetting.

Also some have talked about pods interfering with the air jet on the mouth of the carb. Make sure that the lip of your pods isn't obstructing the inlets to the carbs.

[Haarstad]

A did a dremel fix on the pod boots already, they no longer have that massive lip on them but it didn't seem make a difference. The lip is no longer a problem though.

[LoHo]

This might be a simple fix: Find the vacuum hose that goes from the #2 carb (I think) to the left side timing cover that hooks to the timing advance plunger. I would bet that there is a crack or tear in the vacuum hose.

[jwhughes3]

Completely apart

You pulled emulsion tubes out, pilot jets too and cleared every passage, pulled floats and needle valves and cleaned the screens and fuel inlets?

Sounds like fuel starvation maybe from gunked up screens under needle valves. Only enough gas gets thru to get to 5000 rpm.


I believe you if you state that all that stuff came out etc, but its easy stuff to miss in beginning till youve had them apart.

Good luck
John

[Haarstad]

You pulled emulsion tubes out, pilot jets too and cleared every passage, pulled floats and needle valves and cleaned the screens and fuel inlets?

Sounds like fuel starvation maybe from gunked up screens under needle valves. Only enough gas gets thru to get to 5000 rpm.


I believe you if you state that all that stuff came out etc, but its easy stuff to miss in beginning till youve had them apart.

Good luck
John

Yes sir, emulsion tubes came out along with floats and the hex bolt thing with the screen came out, took the screens off and cleaned all of them thoroughly, there was onle one spot of gunk on one of them because I had already cleaned them all before. My guess is that the gunk moved from somewhere I had missed before. But yes, I completely went through the carbs, even took the choke assembly apart on it.

Can I check the vacuum hose by sucking or blowing through it after inspecting it?

I forgot to see if I still have the ballast resistor but I checked with the tank on and I couldn't see it. When I take the tank off I'll check tomorrow.