Motorcycle Club » Star 1100 Classic & Custom

Carb jetting after new exhaust on 06 and newer

10 posts from 4 voices
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  1. yzcoodermac

    Hey guys got a few questions about the carb jetting after changing out the stock exhaust on My 07 classic.I want to go with the Samson ripsaws or maybe some Pcs pipes.I was originally going to order a Dyna jet kit with the exhaust. But I read on the delpi sloan service site where you have to do extra mods and the maxair kit was the only way to go because of the tps and the cat system.Also something about grinding and drilling.Anyone actually did this on 06 or 07 model.I think I can handle it but I dont really know which kit to use or if it will be biting off more than I can chew.The tech guy At DenDis Kirk reccommended the Dyna jet kit but that was before I read the post at Delphi. Thanks MaC

  2. bkman

    There are a few ways out there to sucessfully deal with the fuel management and emissions equipment. The main issue with modifying later V-Stars is how to deal with the fuel cutoff solenoids and the o-rings on the main jet towers (inside the carb bowls). These can cause an extremely lean condition with an aftermarket intake and exhaust system and, if the bike runs at all, you could damage your engine by leaving these components in place. The o-ring is easy - you just remove it. The TPS is going to remain in place, no matter what intake or exhaust you use (unless you change the carbs, too).

    The fuel cutoff system is the big issue with this bikes. It is in place to protect the catalyst in the OEM exhaust pipes and you should not tamper with it unless you are completely replacing the OEM exhaust.

    I know there is one method of dealing with the fuel cutoff system (it may be ths Sloan one) that recommends drilling and grinding (you've obviously already read about this). That kinda' scared me, to be honest. If you just disconnect the solenoids, you will get a "check engine" light and your bike won't run. Maxair deals with this their own way - they have a kit to remove the solenoids completely, but they do not require any drilling or griding on the carbs. Their kit has some electronics in it that tricks the engine computer into thinking the solenoids are still there.

    Once you disable the fuel cutoff solenoids, the "check engine" light will turn on when you really rev it up because the computer is trying to cut off the fuel, and the engine RPMs are not dropping (as they would if the fuel was shut off). This is not indicative of a problem, however, it just means that you're nearing the redline, and it does not actually disable the rev limiter. I kind of like this little "glitch" myself, because it lets me know when I've gone far enough on the throttle.

    Another problem you are likely to have when changing exhaust is popping when you decelerate (or even at low-speed running). This can often be solved by disabling or removing the air induction system (AIS) on these bikes. However, it can also be caused by a lean pilot circuit in the carbs. That would require an adjustment (at best) or bigger pilot jets. I think it really depends on what you do with your intake.

    Thew only thing I don't like about DynoJet kits is that they don't usually come with pilots, only main jets, needles and slide springs. I also am not sure they always recommend the best needle / jet settings, either, because the two I've used (one on a Honda and one on a Suzuki) were not good the first time. I had to play with needle height and jet sizes before it would run right.

    On my 2008 V-Star, I went with Maxair and I am very happy with it. Their instructions and support are very good. I only had to take my carbs apart one time - it worked the first time for me. Maxair is not cheap, but it includes everything you will need (pilot jets, main jets, needles, springs and new screws for the float bowls) and it seems to be a well-developed kit.

    This job is NOT too difficult, but you have to be VERY careful what you're doing, and follow the instructions (with whatever kit you choose) to the letter. Don't assume ANYTHING and TAKE YOUR TIME.

  3. yzcoodermac

    Thank for the reply any info is helpful.Yeah I saw the fuel solenoid at Max air.Yep they Love their Max Air I may have to save up for the Max air kitI noticed the Dyna jet comes with a Ais plug (aka)a marble.I I read somewhere where someone went with the bigger jet than was reccommended with the kit.Any way I put in a offer for a new set of Samson exhaust on Ebay last night.If I get them I guess Ill have to wait to get the kit before I can install them.Looks like this Mod is going to be expensive.
    B safe MaC

  4. Ghozd608

    I have an older bike 04, but I would recommend Max Air as those guys are great to work with, and will help you all the way thru with any questions!!! Just my Opinion.


  5. bkman

    If you are really on a tight budget, I'd bet money you could just remove the solenoids and tie them up under the tank. Then, all you have to do is go to a hardware store and buy two brass plugs to put in the carb bowls (where the solenoids used to be). That is what Maxair gives you with the CSR kit (the brass plugs) and there's no need to fool the computer into thinking the solenoids are still there when they ARE stil there. Of course, they would click, clack pretty loud when you first turned the bike on (like they do now, but probably a bit louder) and, over time, corrosion may destroy them and cause the "check engine" light to turn on. By then, however, you could have saved up enough money to buy the CSR kit.

    The Maxair kit woke my bike up when I installed it with an exhaust. Their setup really does work well, and you don't have to dink around with it too much. It took me about two months of twiddling with the MaxMix screws to get the idle / low-speed mixture just where I wanted it, but the MaxMix screws make this very easy - I could almost make adjustments at a traffic light (which is why I recommend the MaxMix screws).

    Also, beware that all AIS removal kits are not created equal. I know that some here have found themselves with the infamous "chirping" V-Star. I am not sure which AIS removal kits are the culprits, but I do know that the Midnight Customs ones DO NOT chirp. They are also rather inexpensive (about $30 on e-bay, I believe) and look nice, too.

    Before you disable / remove your AIS, you might want to see how things work with a new exhaust and intake. If you want to remove the chromed tubing that snakes its way around the motor, then you have no choice but to de-AIS it. However, there's no real harm in leaving the AIS connected with aftermarket intake and exhaust systems. The potential is just much higher that you will get deceleration popping or back-firing.

  6. yzcoodermac

    Let me see what I can get the Samson Exhaust for. I put in an offer on them last night.If I can get them for the price I offered I may can get the Max air kit.They sell a solinoid kit that plugs right in and says there is no grinding required I think it sells for about $50.00 from Max air.Too bad they dont sell it with the predator pro kit as a single unit.As for the chirping I dont think you will hear it with the Samson exhaust.Do you think ill need the baffles for back pressure.Someone the other day said they are running the cobra exhaust with no baffles and someone else said they thought they would need it for back pressure to make more torque in the low rpm range.Everyone has there on opinion on this.But it seems that the back pressure thing only makes sense.I want as much growl as I can possible get.Are cones the same as baffles? I may can make my own cones to create back pressure.The baffle would only take away from the rumble im trying to create.These need to be in place before the carbs are tuned as they will make a diffence in how the bike breathes.Enough for now Ill chew on it for for a week or so.
    Hope you were able to get out and ride this weekend it was really niced here in Ala today.Thanks much! MaC

  7. bkman

    ...Hope you were able to get out and ride this weekend it was really niced here in Ala today...
    I am going on a long ride later this week - about 600 miles. I can't wait, but I am not sure what the weather is going to do, and we're going North

    I've been working on some heated clothing this weekend - getting the wiring in place and such.

    I am sorry I can't really offer any real useful information about back pressure, baffles and things like that. I am about the farthest from an expert on the topic as you could get. I would caution you, just the same, against taking any stranger's advice on the topic. There ARE a lot of opinions about this sort of thing, and many of them are based on absolutely nothing factual. Ask ten people, and you'll get twelve opinions!

    All I know is that, most exhaust systems from reputable companies are designed to extract optimal performance as they are configured from the factory. I would be cautious about modifying any exhuast system without some known procedures you can follow, to be sure will work right. That is, of course, unless you are inclined to do a lot of trial and error. In that case, more power to you! Just make sure you can call on the manufacturer, a trusted and experienced mechanic or someone who's actually done the same thing for good advice.

    For what it's worth, my wife's bike (a Honda 750) is running long Cobra pipes with no baffles. It is LOUD when you romp on it, but it sounds good. The jets on her bike had to be up-sized a couple of clicks (beyond what the jet manufacturer recommended) to make it run right, and I had to futz around for a long time to get it dialed in. It is still not perfcet, but it starts and runs well, and the plugs don't look like they're running too hot. I am not the kind of person who really enjoys tearing carbs apart sixteen times so I am leaving well-enough alone.

    If you are inclined to remove your baffles on the Samson pipes (I hope you win them, by the way), I would definitely plan on some experimentation. Just remember that, when airflow increases, so must fuel flow (to keep the balance right). If you are going to remove the baffles on your pipes, it would be best to do so BEFORE you re-jet. If you re-jet first, your probably going to have to do it all over again once you pull out the baffles. Were I in your shoes, I'd definitely give the folks at Samson a call before I began. They may be able to tell you exactly which jet sizes to use with and without baffles, and it will save you a lot of time. If you do end up with the Maxair kit, they will also be very helpful with jetting and such. Just make sure you have all your data in order before you contact them. They are FANATICS about detail and accurate information, because they want to give you accurate and detailed help.

    As for the rumble you want, I can only offer this. My wife and I go to a lot of the local bike nights around central Florida. The deepest, most Earth-shaking pipes I've ever heard were the very large-diameter, short ones. The short, skinny drag-style pipes just tend to be loud, and the longer pipes tend to sound more mellow - not quite as Earth-shaking, but just as deep - as the shorter, large-diameter pipes.

    Good luck in your quest for the best sound and highest performance. Remember, though, that this is an old-school, low-compression, two-valve engine. Without some serious internal mods, it will not be a high-revving , tire-shredding screamer. If you want that, I'd suggest something with two more cylinders and a lot more plastic.

  8. Ghozd608

    I thought I would throu this out there for you, some pipe manufacturers when they build there pipes use a smaller diameter pipe right at the head for a couple inches to get the required back pressure needed. They then go with larger pipe the rest of the way. PCS does this alot with there short agressive exhaust systems that do not run baffels.

    But I also am buy no means an exhaust export!!!!


  9. LiddleBen

    Ok here is my 2 bits worth; I have 2 bikes on one which is a street drag style bike, I run cobra drag pipes. As for jetting I went with Dyna jet stage 3 kit. you must modify the air flow and richen up the fuel mixture to keep from running too lean and possibly damaging the engine. this is generally needed any time you run a full custom exhaust. to raise the air flow I drilled 80 1/4 inch holes in the stock top hat air filter and modified the air box and added a open design K&N filter. On the other bike which is a classic. I totally rebuilt the motor with performance parts. On this motor I used the stage 3 kit and a thunder mfg teardrop breather. I had the carb mods done professionally at a chopper shop and both bikes were tuned on a Dyno. This is expensive, but The results are well worth the cost.If you get a jet kit, It comes with an assortment of jets of various sizes.It also gives you a starting point. You may have to try several sizes before you get optimum performance. Unless you want to take your carbs apart several times and change the jets. I would go the dyno route. As for AIS removal I used the pacific coast star plugs. As for Intake, It is really a matter of choice. All manufacturers claim great HP increases. To that end, whether you go with pods or something else the end result is generally the same. Try to help answer your performance questions. That is more than 2 bits sorry. This is not all as complicated as it sounds.,L.B.

  10. yzcoodermac

    Ok guys after reading all the post on the V star knowledge base.I ordered 117.5 jets for the front and 115 for the rear.The sight has all kinds of useful info on exhaust and jetting.It seems that if you are changing the exhaust (samson)that you leave the stock needles.Several said they changed them out but was advised to go back to stock needles on the 2006 and above.I talked to the owner of Metic Magic(Tim Bondurant) today and he agreed on the sizes of jets .I ordered the jets $5 a piece +free shipping.This is the guy that developed the dragons breath kit.It sells for $220. It opens up the top end,like the Maxair.He agreed that since all Ive done is opened up the exhaust that this should do it.The bike runs fine since I changed out the exhaust ,just has a little hesitation when you give it full throttle .After Iget the jets in Ill keep you posted.Also I was advised to go 3 turns on the pms screw.Then maybe adjust from there.
    You guys keep the rubber side down!


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