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1995 XV1100 stumbling, failing at low RPM and popping [PROBLEM SOLVED]

Have a question about fixing something on a Yamaha Virago XV1100? Post it here!

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EricksonSouza
Posts: 7
Joined: Tue Jun 11, 2019 1:05 pm
Location: Brazil
What Virago you Own: XV 1100 virago

1995 XV1100 stumbling, failing at low RPM and popping [PROBLEM SOLVED]

Post by EricksonSouza » Tue Jun 11, 2019 1:31 pm

Hello guys.
I recently got a virago xv1100 1995.
First of all I apologize for the quality of my english, I'm Brazilian. I really liked the bike, which is very rare here (here is very common the 250 and 535, but not 750 and even less the 1100). Where I live, only one mechanic has accepted service on my bike. I bought repair kits for the carburetors and other things, and after his work and replacing the repairs kits, the bike is reeeeeeally bad.
It was before out of sync, but now it is fully equalized, and the idle speed is steady and rhythmic. Buuuut when I try to ride the first few meters and make change to the second gear (or third), it begins to pop in the exaust, starts to fail, to stumble, and to avoid it dying, I must pull the accelerator really hard. When I do this, it pulls forward in a sudden acceleration. It also fails a lot when I need to slow down, and especially in retakes. At higher speeds the stumble and the popping sound are lower. I don't know what is this, it feels like when you are running out of gas, it's a similar feel (no, my gas tank is full haha). Some things to tell first:
* the air filter is new
* the floats in both carbs are not the originals. I'm waiting a new set, and, meanwhile, i'm using similar floats, with lower quality but compatible.
* Inside the carburetors the mechanic discovers that the high jet that was ther was 117 but in the new kits (and manual) it should be 122 and 125 in the first and second cylinder). Right now, inside the carbs are the brand new 122 jets but i'm thinking in replace them for the ones that she had before (117) to see if that it's the cause.
* I don't know if that's it but it look's like the bike is running in poor condition, I have no idea. I tried to find if there is some air leak or false entrance but couldn't find anything.
* The mechaninc insists that this problem it's caused by the floats because they are not the originals, but it doesn't feel right to me.
* The level of the float's can make richer and poor conditions?
* My spark plug wrench its destroyed (believe or not, my two huskies destroyed...have no idea how) and I can't even check the sparks plug to see the condition.

Sorry if this post it's too long but right now this bike it's my only vehicle, and it sucks to be without my virago...

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ViragoJoe
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What Virago you Own: 1996 Virago Special XV1100SH
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Re: 1995 XV1100 stumbling, failing at low RPM and popping

Post by ViragoJoe » Tue Jun 11, 2019 3:53 pm

EricksonSouza wrote:
Tue Jun 11, 2019 1:31 pm
Hello guys.
I recently got a virago xv1100 1995.
First of all I apologize for the quality of my english, I'm Brazilian. I really liked the bike, which is very rare here (here is very common the 250 and 535, but not 750 and even less the 1100). Where I live, only one mechanic has accepted service on my bike. I bought repair kits for the carburetors and other things, and after his work and replacing the repairs kits, the bike is reeeeeeally bad.
It was before out of sync, but now it is fully equalized, and the idle speed is steady and rhythmic. Buuuut when I try to ride the first few meters and make change to the second gear (or third), it begins to pop in the exhaust, starts to fail, to stumble, and to avoid it dying, I must pull the accelerator really hard. When I do this, it pulls forward in a sudden acceleration. It also fails a lot when I need to slow down, and especially in retakes. At higher speeds the stumble and the popping sound are lower. I don't know what is this, it feels like when you are running out of gas, it's a similar feel (no, my gas tank is full haha). Some things to tell first:
* the air filter is new

* the floats in both carbs are not the originals. I'm waiting a new set, and, meanwhile, I'm using similar floats, with lower quality but compatible.

* Inside the carburetors the mechanic discovers that the high jet that was ther was 117 but in the new kits (and manual) it should be 122 and 125 in the first and second cylinder). Right now, inside the carbs are the brand new 122 jets but i'm thinking in replace them for the ones that she had before (117) to see if that it's the cause.

* I don't know if that's it but it look's like the bike is running in poor condition, I have no idea. I tried to find if there is some air leak or false entrance but couldn't find anything.

* The mechaninc insists that this problem it's caused by the floats because they are not the originals, but it doesn't feel right to me.

* The level of the float's can make richer and poor conditions?

* My spark plug wrench its destroyed (believe or not, my two huskies destroyed...have no idea how) and I can't even check the sparks plug to see the condition.

Sorry if this post it's too long but right now this bike it's my only vehicle, and it sucks to be without my virago...
Erick,
FIRST:
1. Has this Virago been modified in anyway from its off the assembly line condition? like exhaust?

2. How did the bike run prior to the installation of the repair kits.

3. Where the carburetors cleaned thoroughly or just the installation of the repair kits. Were the wrong floats detected then?

That's good that you are getting the correct Floats!! Floats control the flow of fuel and must be set correctly. Floats too affect lean and rich fuel conditions.

Jets control the richness or leanness of the fuel delivery to be burned. Front cylinder runs on the lean side while the rear cylinder runs on the richer side.

What cylinder are you labeling or calling number #1? Front or Rear?

Buy another spark plug socket wrench to pull those plugs to see what is going on in your engine. Keep track of what cylinder they came out of. Post pictures so we can see them.

Read these articles:
Hitachi first then Mikuni

Virago Hitachi Carburetors
https://www.viragohelp.com/virago-hitachi-carburetors/

Virago Mikuni Carburetors
https://www.viragohelp.com/virago-mikuni-carburetors/
ViragoJoe
1996 XV1100SH Virago Special
"Never ride faster than your Guardian Angel can fly!!"
;)

EricksonSouza
Posts: 7
Joined: Tue Jun 11, 2019 1:05 pm
Location: Brazil
What Virago you Own: XV 1100 virago

Re: 1995 XV1100 stumbling, failing at low RPM and popping

Post by EricksonSouza » Thu Jun 20, 2019 9:58 pm

ViragoJoe wrote:
Tue Jun 11, 2019 3:53 pm
Erick,
FIRST:
1. Has this Virago been modified in anyway from its off the assembly line condition? like exhaust?

2. How did the bike run prior to the installation of the repair kits.

3. Where the carburetors cleaned thoroughly or just the installation of the repair kits. Were the wrong floats detected then?

That's good that you are getting the correct Floats!! Floats control the flow of fuel and must be set correctly. Floats too affect lean and rich fuel conditions.

Jets control the richness or leanness of the fuel delivery to be burned. Front cylinder runs on the lean side while the rear cylinder runs on the richer side.

What cylinder are you labeling or calling number #1? Front or Rear?

Buy another spark plug socket wrench to pull those plugs to see what is going on in your engine. Keep track of what cylinder they came out of. Post pictures so we can see them.

Read these articles:
Hitachi first then Mikuni

Virago Hitachi Carburetors
https://www.viragohelp.com/virago-hitachi-carburetors/

Virago Mikuni Carburetors
https://www.viragohelp.com/virago-mikuni-carburetors/
Hi! sorry if I took to long to respond.
Lets go:
1: The bike came alreayd with two VANCE & HINES exausts for Virago's. I think I am the third owner of this bike. The second one had some problems with the originals and buyed the vance and hines ones. he used to love the sound (I really like too).

2. When I got the bike it was completly out of sync I think, idle really hesitating. And was sucking gasoline like a black hole. I do not know what the measurement would be like for you guys, but here I was running 8 km per liter (it would be like 19/20 miles per gallon I guess), usually in the city, no passing the 50/60km/h (30-37 mph). I bought the kits because I had already scheduled a complete inspection/review on the bike with the mechanic, and the former owner had advised me to change the float needles, seats,gaskets and check the condition of the jets. Because of this, since the carburetor would be opened anyway, I asked the mechanic to change everything for new jets. Now I bitterly regret having asked for this exchange. I thought the jets that were inside the carb had the originals measurements but I was completely wrong.

3. Yes the carbs were clean. They were in good condition except for the floats, and another thing that I will explain i more details.
I was calling the cylinder 1 rear cylinder because that's how it is written on them.Maybe I got confused as to which jet should be in each cylinder but it does not really matter because last week I decided to remove the carbs and inspect if the mechanic did something wrong.
And... man...
3 things were completely wrong:
1 * The floats were very high, something like 35mm, and the other one 33mm (I think it should be 23mm right?)
2 * The jet that goes on top of the emulsion tube (the 122 or 125 one) was literally stuck. It does not unscrew and when I turn, it rotates along with the emulsion tube.I really have no idea if it was already this way or if the mechanic did this damage. But from the state of that part it seems like it have been this way since I got the bike. The jet that is stuck is measure 122 (it should be the 125 I guess but I can't remove it so...).

3. * The pilot screw was almost 4 turns in both carbs. I guess with so many turns like that, it lose the effect, right?

I made some adjustments like:
1: I put back the old jet 117 of the carb of the front cylinder that was there before the change.
2: I checked the other jets and they were clear.
3: I did blow some air in the stucked jet (the 122 one) and was ok, nothing was clogged.
4: I set the height of the floats to 23mm.
5: I changed the pilot screw to 2 turns on each carburetor. I think this is my biggest challenge right now, hit those screws, which is a huge challenge without the right tools because turn them with the carburetor in place in a very tight space it's so hard.

The result is that the problems cited in my first post have been greatly reduced. The bike is no longer poping, and the hesitation at low below rpm ts almost gone.
I can still feel some gags at low speed but nothing like before. I think I still have to reach the right measure. I also think I missed the esync after I removed and put back the carbs.

Well, that's all for now. I have the new floats. I'm still getting the nerve to remove the carburetor and put them in place. The most difficult part of this task is to have access to the internal bolt of the intake manifold, it is an unfortunate task.
I've already ordered the right wrench for the plugs.
Thanks for the help, if you have any advice on the issues I quoted above I would be grateful.

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ViragoJoe
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What Virago you Own: 1996 Virago Special XV1100SH
"Never ride faster than your Guardian Angel can fly!!"

Re: 1995 XV1100 stumbling, failing at low RPM and popping

Post by ViragoJoe » Fri Jun 21, 2019 7:44 am

Erick,
This video may help you with the removal and installation of the carburetors:
https://www.youtube.com/watch?v=L9TZOLgop3I

More information:
viewtopic.php?f=64&t=575&p=2467&hilit=c ... oval#p2467

Float Adjustment:
viewtopic.php?f=44&t=368&p=741&hilit=carburetor#p741
ViragoJoe
1996 XV1100SH Virago Special
"Never ride faster than your Guardian Angel can fly!!"
;)

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Eric
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What Virago you Own:

Re: 1995 XV1100 stumbling, failing at low RPM and popping

Post by Eric » Sun Jun 23, 2019 3:42 pm

Hope you get it all squared away man. I found it easier to just loosen those bolts (intake manifold) the ones that are hard to get to. The intake boot is slotted. Just loosen and turn the carbs clockwise. With a little jiggling should come off the intake boot. That is the way I did it. 1986 vx700. Hitachi carbs.
Hope this helps.

EricksonSouza
Posts: 7
Joined: Tue Jun 11, 2019 1:05 pm
Location: Brazil
What Virago you Own: XV 1100 virago

Re: 1995 XV1100 stumbling, failing at low RPM and popping

Post by EricksonSouza » Thu Jun 27, 2019 11:30 pm

Eric wrote:
Sun Jun 23, 2019 3:42 pm
Hope you get it all squared away man. I found it easier to just loosen those bolts (intake manifold) the ones that are hard to get to. The intake boot is slotted. Just loosen and turn the carbs clockwise. With a little jiggling should come off the intake boot. That is the way I did it. 1986 vx700. Hitachi carbs.
Hope this helps.
Hi! so I realized that my bolts are different from the factory. They are ALLEN, I don't know if it is the same name for both of us. They are like this:Image
I bought this tool for allen bolts.
Image
In the end it have this hexagonal form, so you cant turn even if it's not right there, just with the tip. It was waaaaay easy with this.
Image

But thank you anyway man!

Well continuing, I installed the original floats, and left the pilot screws in almost 2 turns (returned a bit compared to before. Before I left them with two turns and 1/4 and now I went back to almost 2 turns).
With the first adjustment (2 and 1/4 turns) the bike kid 8km/l per liter.
With my new adjustment (amolst 2 turns) it did 11,5km/l, but the problems with stumble that I related it is still there.
It still continues to fail, usually at low rpm and in the firsts gears (2nd and 3nd, when I change to 4nd it almost dissapears but if I keep at low speed you can feel the stumble.). I really do not know what the problem is or what to do.

The mechanic swore to me that he adjusted the valve clearance to the factory standard, but I no longer believe in him. Is it possible for the virago to have these types of stumbles because of poor regulation of valves?

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ViragoJoe
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What Virago you Own: 1996 Virago Special XV1100SH
"Never ride faster than your Guardian Angel can fly!!"

Re: 1995 XV1100 stumbling, failing at low RPM and popping

Post by ViragoJoe » Sat Jun 29, 2019 10:49 pm

Previous owner must have changed the retaining bolts for the carburetors from hex to Allen bolts.

"The mechanic swore to me that he adjusted the valve clearance to the factory standard, but I no longer believe in him. Is it possible for the virago to have these types of stumbles because of poor regulation of valves?"

Yes, tight valves can cause misfires. Loose valves are less of a problem, however, too loose can cause damage between the valve stem and the tappet adjuster. Not to forget to mention the engine will be much noisier.

Check the clearances, it won't take that long to do.

Adjusting Virago Valves
https://www.viragohelp.com/virago-owner ... go-valves/

CRANKSHAFT NUT ACCESS FOR VALVE ADJUSTMENTS ETC. [INFO]
viewtopic.php?f=6&t=805
ViragoJoe
1996 XV1100SH Virago Special
"Never ride faster than your Guardian Angel can fly!!"
;)

GINO
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Re: 1995 XV1100 stumbling, failing at low RPM and popping

Post by GINO » Fri Jul 05, 2019 5:29 am

Decent need to accomplish something like this with mine

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Yogi4
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What Virago you Own: '92 Virago XV750D

Re: 1995 XV1100 stumbling, failing at low RPM and popping

Post by Yogi4 » Fri Jul 05, 2019 7:48 pm

Does anyone have the specs to convert the 10mm manifold boot bolts to Allen head like EricksonSouza has?? My local True Value has eliminated a lot of their stock nuts and bolts. And trying to eyeball the threads and diameter with an old pair of eyeballs is well... daunting. Got new manifold boots, might as well upgrade the bolts too. Anything to make the carb removal/installation process easier is welcoming. Mines a XV750 but I'm assuming they should have the same thread pattern.
"May the good news be yours!" - Les Nessman

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ViragoJoe
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Posts: 1067
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What Virago you Own: 1996 Virago Special XV1100SH
"Never ride faster than your Guardian Angel can fly!!"

Re: 1995 XV1100 stumbling, failing at low RPM and popping

Post by ViragoJoe » Sat Jul 06, 2019 2:53 am

Yogi4 wrote:
Fri Jul 05, 2019 7:48 pm
Does anyone have the specs to convert the 10mm manifold boot bolts to Allen head like EricksonSouza has?? My local True Value has eliminated a lot of their stock nuts and bolts. And trying to eyeball the threads and diameter with an old pair of eyeballs is well... daunting. Got new manifold boots, might as well upgrade the bolts too. Anything to make the carb removal/installation process easier is welcoming. Mines a XV750 but I'm assuming they should have the same thread pattern.
Yogi,
Remove one of the screws and take it to your True Value Hardware, Home Depot, Lowe's, or Menard's that carries metric screws/bolts. These places will have a screw/bolt gauge mounted in the screw/bolt isle. Check it for thread size and pitch. Then get the correct length or the closest to it. Easy peezy.

If you are a real screw/bolt enthusiast. You could get one of these. A Screw/Bolt thread gauge. Lowe's and others sources carry them.
$4.98 as of this writing.

https://www.lowes.com/pd/irwin-metric-t ... gLAx_D_BwE

Click Image to Enlarge
Screw-Bolt Thread Gauge-Metric.jpg



And for the diameter:
Hillman 13-in to 64-in Standard (SAE) Thread-Gauge (Also has Metric diameters on it)
$1.98 as of this writing.

Click Image to Enlarge
Screw-Bolt Thread Gauge Diameter.jpg
https://www.lowes.com/pd/hillman-13-in- ... gLE5_D_BwE
ViragoJoe
1996 XV1100SH Virago Special
"Never ride faster than your Guardian Angel can fly!!"
;)

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