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Hey guys....been a while since I was on here. I wonder if any of you may have some info on a couple things. I have a 2011 vStar 1100 Silverado. My serial number lists it as a 2011 XVS1100. This is all good though.....but why, when I go to get aftermarket parts, is there never a listing for a 2011 vStar Silverado, the vStar line only goes to 2009? I'm looking to order a dynojet kit for my 1100, since I put a Cobra slip on muffler on, the bike seems to be running lean. Talking to my mechanic, he says a Stage 1 DynoJet kit should fix the problem. When I emailed DynoJet, they say there is no listing for a 2011 XVS 1100, that Yamaha discontinued the product line after the 2009 year. Can anyone tell me.....is there any difference between the 2009 vstar 1100 and the 2011 vstar 1100, mine is still carbeurated as well. Or better yet, what kit they used and possibly a part number....
Thanks in advance for any info you may be able to provide me.
Jay
 

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I will second nick57. Rejetting for slip on exhaust is not needed. Follow the link for PMS adjustments. The 2010 and 2011 Vstar was a Canadian model only.

 

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It depends on the slip-ons or exhaust that you are using. At the very least you might have to enrichen your idle mixture screws but more likely your best bet is to shim your needle. The funny thing is that most jetting mods you'll find will address the idle mixture screw and/or the main jet yet both affect the extreme ends of the operating range. You'll probably get better results by shimming the needle which affects the mid-range, where you do most of your riding. Not to say that adjusting the extremes won't get you by but personally I'd rather get the mid-range right instead of having over-rich lows and highs compensate for the mid-level leans.
 

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the pms screws affect the carbs over the entire range. needles come in at mid range and have no effect at wide open throttle. changing pipes affect wide open throttle.which causes a lean condition.

its also recommended to up the mains one size when changing the pipes to keep from a lean condition at wot. changing the pipes causes backfire on decell. increasing the pms a little will put gas in the exhaust and lessen popping.
 

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the pms screws affect the carbs over the entire range...
Not really because the small amount of fuel it meters at idle becomes almost inconsequential the more you open the throttle.

Granted this diagram pertains to round slide carbs but effectively applies to CVs as well.
 

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Discussion Starter #8
Thanks for all the replies here guys, really appreciated. Is there anyway that popping could indicate a rich condition? Reason I ask is that when I pulled the intake boots the one for the rear cylinder looked to have unburned fuel in it. I pulled the carbs, and they currently have a 115 main in the front and a 112.5 in the rear. The PMS screws were plugged off, but I pulled them out and checked the settings there too. Both PMS screws were out 2 turns from a light seat. Does anyone know what stock jetting would have been, maybe this is it, not sure. I'd like to have some sort of starting place. With those current jets, the bike would start ok and seem to run fine. It would pop on deceleration, and after riding for a bit, and I shut it off for a few minutes, I would have to open the throttle to get it to start up again, like its was flooded. When I pulled the plugs, they weren't fouled black or wet, they looked pretty good actually, maybe a tad hot, but didn't look like rich to me. Anyone else experience this sort of issue? And again, any info on stock jetting would be appreciated.
Thanks again
Jay
 

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Follow the link in previous post. About half way down link page is chart.



Sounds like you have a vacuum leak causing a lean pop. The extra fuel could be sticking float. Read the entire article as it will answer almost any Carb issue questions. Keep us informed.
 

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Thanks for all the replies here guys, really appreciated. Is there anyway that popping could indicate a rich condition? Reason I ask is that when I pulled the intake boots the one for the rear cylinder looked to have unburned fuel in it. I pulled the carbs, and they currently have a 115 main in the front and a 112.5 in the rear. The PMS screws were plugged off, but I pulled them out and checked the settings there too. Both PMS screws were out 2 turns from a light seat. Does anyone know what stock jetting would have been, maybe this is it, not sure. I'd like to have some sort of starting place. With those current jets, the bike would start ok and seem to run fine. It would pop on deceleration, and after riding for a bit, and I shut it off for a few minutes, I would have to open the throttle to get it to start up again, like its was flooded. When I pulled the plugs, they weren't fouled black or wet, they looked pretty good actually, maybe a tad hot, but didn't look like rich to me. Anyone else experience this sort of issue? And again, any info on stock jetting would be appreciated.
Thanks again
Jay


You advance the timing when you twist your throttle, thus you could have actually been lean and the timing advancement got it to fire. You shouldn't open the throttle while starting the bike as you can get a kick back and mess up your valves from what I hear.

Check that your choke/linkage is working right and it is open all the way when not in use. Did the car balance get screwed up? Are you getting good spark, all the time on both cylinders? The bike has 2 coils and if the coil for the rear plug is heating up and dropping out it could explain unburnt fuel and hard starts when bike is hot (rear cylinder flooding). Is the fuel pump running a lot? Fuel filter is good and no fuel lines kinked? Running normal Octane fuel that is good? Is your idle set too low, even if it isn't it will start easier if you turn it up to a higher idle while troubleshooting. Intake leaks will cause popping and lean conditions. Check the simple stuff first I fought with Jetting for about 3 months and it was the fuel filter clogging up and releasing and clogging...... This caused a lot of popping, random changing issues with the mixture and how my bike ran, it would sputter in left hand turns only because that bowl would starve first from the poor fuel flow and carb balancing was impossible. The fuel pump would run a lot when I first turned the key on, after I replaced the filter I never hear it run, and all issues cleared up.

Slip-ons will have no real effect when starting your bike unless the muffler is plugged off. Also if you don't have the Carb Vent tucked out of the wind inside the dog dish for the Air Filter, it can cause popping and lean conditions while riding if wind is pressurizing it.
 

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Discussion Starter #11
I'm back guys!! OK so here is what I've found so far. Never did the dynojet kit, Left jets the way they were, and set the PMS screws to 2.5 turns out, they were originally 2 turns out. New fuel filter, fuel pump runs momentarily when I turn the key on, but that's all I hear from it. Sprayed some WD40 around the intake boots and area to check for vaccuum leaks, no change in rpm, so I'd say there's no leaks. I run a mid grade fuel, 89octane I believe. Fuel lines aren't kinked and are clear too. The carb vent is also tucked in the dish on the filter as well.
My whole reasoning for doing this is that it was popping bad on decellertation and that it always seemed like it was flooded when I'd go to start when it was hot. What I've found when pulled the carbs off was a little puddle of fuel in the air boot for the rear carb. I'm thinking now that I have a bad needle and seat in that carb bowl and it actually IS flooding it out. I've attached a picture looking straight down into the air boot from where it would attach to the airbox. The top of the picture is the front of the bike. What do you guys think?
 

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It depends on the slip-ons or exhaust that you are using. At the very least you might have to enrichen your idle mixture screws but more likely your best bet is to shim your needle. The funny thing is that most jetting mods you'll find will address the idle mixture screw and/or the main jet yet both affect the extreme ends of the operating range. You'll probably get better results by shimming the needle which affects the mid-range, where you do most of your riding. Not to say that adjusting the extremes won't get you by but personally I'd rather get the mid-range right instead of having over-rich lows and highs compensate for the mid-level leans.
i could never understand what mid range actually is, i'v watched the slides on my 650 and they start lifting right off idle and just just about 3/4 throttle their full up after that point the only thing the throttle does is let more air in, it seems to me needles are a tricky thing to get just right
 

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... i'v watched the slides on my 650 and they start lifting right off idle and just just about 3/4 throttle their full up after that point the only thing the throttle does is let more air in, it seems to me needles are a tricky thing to get just right
I'm assuming you looked at the carbs while the bike was on it's side stand and you revved the motor? The motor needs to be under a working load to get jetting right and have the CV carbs respond accordingly. Yes it's a pain in the arse to get the right needle and needle-jet combo but at the very least with mild mods it could just be a matter of shimming the needle.
 

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I'm assuming you looked at the carbs while the bike was on it's side stand and you revved the motor? The motor needs to be under a working load to get jetting right and have the CV carbs respond accordingly. Yes it's a pain in the arse to get the right needle and needle-jet combo but at the very least with mild mods it could just be a matter of shimming the needle.
it was a slow process to get mine right, one thing i learned right away was if you go too big on the main even by a little it will cut back on the top speed, with a 105 main in mine i can break 90 mph go to a 110 and it won't break 80mph, i remember the model airplane i had when i was a kid and how when it ran out fuel it would spin faster and faster until it was so lean it was screaming no mas just before the sputter die out, i guess its same with any internal combustion engine, rich equals more pulling power but lean equals more rpm. its really about how the engine is used that should determine the tuning, like flat track, drag race, or general purpose. the thing about carbs is you cant add a bit more fuel on deceleration only. like you can with an ecm or a tuner. so when you tune out the popping on carbed engines your actually detuning it.
 
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