Hi Folks,


Current Setup:
2006 Roadstar Midnight 1700
Baron Jet Kit: 172.5 main, 3rd clip, 3.25 PMS, duration screw all the way in.
Hard Krome - 2 into 1 Sideburners
K&N High Flow filter and Box, similiar to the Baron BAK.
AIS removed.
Ontario, Canada 600 ft ASL

I had my r* dyno tested today and got some interesting results.
Can you believe it, the plugs were white, indicating a very lean condition.
After speaking to the shop ( very well respected up here in Canada ), the owner told me these highflow airfilters pump so much air into the carb, it makes it next to impossible to tune the bike properly in conjunction with an exhaust pipe with a 4" opening. We went into the Dyno room and ran the bike...as soon as he covered 3/4 of the filter with duct tape, the bike ran better than ever, although not totally dialed in yet. He recommended I use the stock air box with a K&N filter. He also told me to use 92 octane rather than regular because apparently US gasoline is way better than Canadian and our 87 will gum up the engine. Once all the hardware changes, rejetting and dyno are done, I will update you all on the results.

keep in mind if you were running very hard or hot it will turn your plugs white regardless of you jetting... also remember roadstars will run great very rich, until the exhaust valves start sticking from the carbon build up... I've got the K&N speedstar filter / box and modified stock exhaust self ported intake and I'm running a 167.5 main jet... it ran great with the 172, but it was rich... I dropped to a 170 and she ran great but still a little rich.. so I dropped a final time to the 167.5 all with baron's needle .. now I'm a little lean, I noticed a small drop in power, but a great increase in gas milage.. she'll still outrun my buddies Kaw vulcan 1600 (highly modified) and my other friends harley without even blinking an eye... she'll spin my bridgestones and makes me a little leary of hitting the throttle in first while making a turn... ~Guido

also about high octane gas: the higher the octane the slower the gas burns.. our bikes have low compression pistons, if you running high compression pistons you may need higher octain to stop knocking, but the longer a fuel takes to burn the more likely it won't be completely burnt when it enters the exhaust port, hence carbon build up and for our bikes sticky valves.<br><br>Post edited by: davehrn, at: 2006/05/16 21:40

Why do all you guys want to go leaner? 35 miles to the gallon is plenty. I noticed you didn't say what size pilot or air jet you're running. For normal driving speeds, these are the jets that will be utilized the most.

Your shop owner, although respected, is a little off the mark. It doesn't matter what kind of air box or pipes you have, they can all be tuned to make it work. The problem is many shops don't want to take the time to do it, because it's hit and miss. No two bikes are the same. YOU HAVE TO PLAY WITH IT. See what works and what doesn't, and you don't have to ride it for miles to figure it out.

I started out stock with my 2006 Roadstar Midnight Silverado. I changed the air box to Kuryakyn's Hypercharger, and the pipes to Vance &amp; Hines 2 into 2 things, removed AIS. Stock carb jets are 182.5 Main, 35.0 Pilot, 2.0 Air Bleed. Changed carb jetting to 37.5 Pilot, 1.3 air bleed, needle in 2nd notch, and the stock 182.5 main. This was a little to lean and caused a spitter, sputter, and backfire problem when cold. Changed the Pilot jet to 40.0. Bike runs so good I can hardly stand it. Small adjustments, one step at a time. (Austin, Texas, Elev. 956 asl.)

White plugs are a sign of a lean condition. This is bad. Stuff gets to hot, stuff melts. Done that, been there.

As far as carbon buildup on the valves, Yamaha has a problem with the valve guides that they don't want to tell you about. There is a problem with carbon buildup on the guides and then the valves stick. It's a defective batch of valve guides, but Yamaha hasn't advertised this yet. This is a warrenty problem, and if it happens to you, take it to your dealer for repairs.

Yes, if you go lean you will get better gas milage, but you engine won't take that for very long. Hey, it's your money. Buy new engines every year if you want.

Keep in mind that changing the MAIN jet does not fix all problems. The Pilot jet is 0 -1/4 throttle, Needle is 1/4 to 3/4, and Main is 3/4 to Full. The air bleed jet assists the pilot jet. Bigger number is richer. OH, take the tape off. That's a lazy way to fix it. More of a bandaid than a fix. Jetting my man, jetting. It's a wonderfull thing.

Well, hope this helps my Canadian friend.<br><br>Post edited by: russdustus, at: 2006/05/17 09:40

Why do all you guys want to go richer? 78 hp and 98 ft pounds of torque (enought to light up the back tire when pulling off the line is more than enough...

I'm joking with you .. mostly... yes, to lean is bad, but to rich is bad also... you have to come close to finding the perfect mix ... every bike being different means lots of work to find that fine line, also you have to consider that being a carburated bike it is highly influenced by many outside factors, temp &amp; altitude being the strongest.... you have to consider when you do the majority of your riding and how to best set up your bike... I do most of my riding at 1100 feet above sea level and in 80 degree heat, I will ride in 40 degree temps occasionally, now my bike is a little lean in those cold temps, it takes a little longer to warm it up... but it doesn't show any symptoms of being lean (once warm)... now that summer is here she's nearly dead on... and trust me, I do watch the heat of the engine in the heat of the summer...

One of the ways we learn how to set up these roadstars is by talking to other people's set up and that gives us a starting point.. hundreds of riders on the delphi site have agreed that our bikes will run great rich, even really rich... with only a little black smoke to give it away.. ever run your finger on the inside of a exhaust pipe on a bike thats running rich, it comes away covered in black soot... that is what causes the problem with the sticky valves.. and it maybe a design problem but... if I can avoid the problem with my bike, and have the jetting correct, and avoid some highschool kid from taking my bike apart at the dealership... then I'm one happy camper.. ~Guido

OK, Davehrn, I can see your points, and all would appear to be valid. I had a 1999 Silverado, and started having serious backfiring and sputtering problems, so I traded it for a new one. The shop finally fixed it, and I was told it was little things in the carb, which I had suspected anyway.

When my new one started skipping and sputtering, I questioned the coils. It didn't seem that the front was firing the same as the back jug, but the shop insisted that there was nothing wrong with the coils. Other Yamaha shops I have talked to stated that they have never had coils go bad. I'm still not convinced.

Also Davehrn, maybe your jet numbers are not the same as Mikuni numbers, since I don't know which kit you are using. However, I notice you never talk about changing your pilot jet. Have you ever adjusted it? Surely you don't run wide open all the time, do you? Only in Nevada!

In closing, I think our Canadian friend who asked the question is now more confused than he was before he asked whatever it was he asked. I know I am.

Have a good day.
American by birth, Southern by the Grace of God! <br><br>Post edited by: russdustus, at: 2006/05/18 09:08

To be real clear folks, mileages below the forties are indicative of over rich jetting. The bike may run great, but somewhere in the throttle range, your too rich. Exceptions should be stated here for heavy throttle drivers, but mileage in the thirties should be payed attention to.

Road Stars will tolerate rich settings, but in time will build up carbon on the valve stems and guides. If you keep settings this rich, be sure to do a techron shock treatment just before each oil change to keep the engine clean (full bottle in the tank, full tank of gas, run it out and refill with gas only, then change the oil).

Stock Road Star's tend to get get mileage in the high forties to low fifties depending on driving style. They will tolerate jetting that is pretty lean and are designed to deal with it (had to be for emission purposes).

Harleys are run MUCH richer than Road Stars are. If you run a HD this lean, they start melting engine parts. Be careful not to use any experience with HD to help you determine proper jetting for Road Stars. The engines are dramatically different even though they are both air cooled V-twins.

@russdustus, Dave is running a Baron's jet kit, which uses standard Mikuni jets.

@Topher, If the dealer covered up 3/4 of your air intake and the bike ran better, that simply means that your jetting was set too lean. Enriching the jetting would resolve the problem without having to revert back to the restrictive stock airbox. I suspect the dealers opinions are based on their own experience, and that they have never taken rejetting for aftermarket accessories too seriously. It is tougher to nail, and requires a fair amount of experience with to get right without redoing it a few times. They may have found that they could resolve these types of problems most quickly by reverting to the factory accessories.

GRAM

ya, as per doc, I'm running mikuni jets with baron's needle... I have the stock pilot jet in it, I found my bike able to be run rich at idle by adjusting the pms, but I do also keep the accel screw in nearly its stock position.. I did have to richen the pms screw from stock with the new air kit, but not much... trying to adjust these carbs can be like tying to juggle.. going a little richer on the PMS (which is in play from idle to full throttle) and a little leaner on the jet and needle seems to me and my bike to give me a better response than upping the pilot and going down on the PMS... man this stuff gets intricate.. and I truely believe that some bikes will not run how mine is set up... I'm sure we could argue &quot;theory&quot; all day long and I'm sure both our bikes run great... I just didn't like the 35 mpg I got with the higher jet.. I can now get 53 at 55mph, and 48 at 75mph.. she still runs strong, and I'm sure if you checked my mix with an exhaust analyzer you'd find her a tad bit on the lean side.. which is right where I want her... ~guido