| Author | Message | ||
     Castlehead |
Well there has been a lot of talk about jet changes, and since that was the first thing I did last spring, I will give y'all some hints. You will have to pick the jets you think are right for your bike under the conditions, and altitude you ride in, but I will try to give you some advice on how to make the change easy. (from previous post) Remove the air cleaner cover, the easy way to do this has not been invented, as this whole set up is a chinese fire drill. Uncrew the little set screw at the bottom first, then using a flat head screw dtiver pry the rest of the clips up and away from their lock points. This is pretty strieght forward, except for the one on the very top above the carb. This one you will be tempted to take the tank cover and tank off just to get at the bloody thing... Don't, just pull the cover out from the carb, then push it up twards this last clip until it free itself. This will take a little manipulation, and a few choice words!!! Now remove the reat of the retainer screws off both sides of the engine, and remove the whole plastic piece of ---t from the carb. This is a good time to do the breather modification I talked about above. Now you will have to loosen each of four screws to remove the float bowl. This is no easy task, and it is likely that you will strip the heads of the philips head type screws, as they are of the cheap Japanees variety, that makes most bikes into litter, after only a few years. Well the manufacturer ( and the Government ) just doesn't want you in there in the first place. I had to take my carb compleatly off to get the striped screws out, and the second time I got smart and went to the local fitings shop, and got Allon Head replacements for these Cheep peices of ••••. A good idea, and I recomend it even if you will only be there once. (once is never enough) If you have not piped your bike, leave the main jet stock, cause you will just eat more gas, and get less power otherwise. If you have piped your bike, I recomend the dino. Dial that little puppy in, where you want the power to be... Otherwise just go up one jet size on the pilot jet, and get rid of the pop corn, popping, that you get on closed throttle. When you mess up the heads of the Philips head screws, and I do mean "When"! Take the carb off the bike by uncliping the wire conection to the ignition system, throttle sensor and enritcher, and lossen the throttle cables at the twist grip on the handle bar. Then remove the screws holding the throttle cable bracket to the wheel, that actuates the butterfly plate in the carb. Then disconect the cables, or you will never get the job done. Be carfull not to loose the brass fitting that seats the top screw in its possition, at the top of the carb, or it will not go back together right. You may want to remove the tank to do all of this as it makes it a lot easier to see everything. Some advice on that is wise at this point! No open flames, or heaters, water or otherwise, when removeing and installing this peice of •••• tank! It sure is nifty the way it comes on and off, and needs no real expanation, but the guys at Buell, not being the guys at Harley, who have had to remove tanks for about the last 90 years or so, did not learn an early lesson that HD got down years ago. When you set the pet cock positions on a fuel valve, do not make them so the closed position faces down! (big law suit waiting to happen) This being the lowest place on the tank itself, it tends to trip itself when you place it on the floor, and leak gas all over your garadge. Just a little... bit of a fire hazard! It also trips from this position to the open position ever time you try to remount the tank! I mean "EVERY ____ING TIME" you try to put the tank back on......!!!!!!! Got some real minds there at Buell!!! Even if you try to tape it in the closed position before you put it on, it still leaks all over... Take the bike outside before you take off or replace the tank, or in the imortal words of the owners manual, "this may result in DEATH or Serious INJURY" or Both! Every time I remove the tank I utter the same words "----ing idiots" over and over again! Unless you have a mirror, this this the way to do the jetting anyway, as you wont be able to see the jets, unless you take off the carb. I can do it now with ease as I have replaced the screws, with allons, and know where the jets are. You will likely have to remove the float to do the pilot jet anyway, make sure you drive the pin out the right way or you will need a new carb!!!!! It's the end without the stopper thing. Look at it first! Best of Luck! CastleHead AKA Barry sorry about the spelling, I hate this things spell check. | ||
| Spudman |
Thanks All for the jetting info, The V&H is a Christmas gift, so it won't be installed until after the 25th. I'll try to take good notes and pics and post here for everyone's amusement. I'll pick up a 45 and 170 jet before I start the project. Did anyone also drill the slide or adjust the low-idle screw? Did anyone change needles or move the clip? What impact has it had on mpg? I know these things are lean from the factory, I just don't want to fatten it up too much and loose power. spudman, trying not to be too fat | ||
| Aikigecko |
After some stupid question sessions (on my part) with my service department I found out that what you describe above about jetting is what they did to my Blast (Now referred to as Turtle). I didn't actually discover the rev limiter until I changed to the V&H pipe. The power difference was astounding to me. From what I understand K&N actually makes a filter that fits in the stock turd, I mean airbox, but I would rather see variety of new intakes. Write to Force Motor Products ( email fmp@redrivernet.com ) and tell them to release their sidewinder before spring. Peace Tony 00 Blast | ||
| Topcat |
I changed the jets on Dee's Blast! today. Big differance! After the V&N exhaust change only the bike ran alot better but would pop and backfire when when rev'ed. It was also harder to start when the engine was warm. I changed the low speed jet from a 42 to a 45 and the main jet from a 165 to a 170. It now starts easy cold or hot, rev's smoothly and hauls a$$. I'll check the sparkplug in a couple of days to make sure it's not running too rich with these changes. Tony, Thanks for the info about the K&N airfilter. My dealer doesn't know about it so I'll call K&N Monday and ask them. TC | ||
| Aaron |
I got max power with a 170. Also a 45 pilot and N65C needle. That was stock exhaust and air cleaner, though. Stock jet is a 165. I noticed in the White Brothers write-up in the current Battle2win that they also used a 45 with a 170, and found some power. Sorry about the too-large dyno sheet. I updated Winpep recently and it's default .bmp export size is bigger than the old version. AW | ||
| Aaron |
FYI ... here's a dyno sheet from my kid's Blast ...  As delivered, the power was way down compared to most Blast dyno sheets I've seen. The timing was a mile too advanced. Then we messed with the jetting. The last pull there is with the air box open. Removing the element did not make more power, it was the act of opening the airbox that made the dyno chart jump. AW | ||
| Bluzm2 |
Aaron, Is the bike still totally stock? No pipe etc.? Just curious BluzM2 | ||
| Aaron |
Yes, it's totally stock, although when we went to rejet, we did pull the crankcase breather out of the airbox. That's the one and only mod. Oh, we put in a K&N but it made no difference on the dyno. Near as I can tell, 27's are pretty typical for box stock Blasts, this bike may be a tad weaker than average, considering how much careful tuning I had to do to reach 27. I have every intention of changing that, though! AW | ||
| Dougp |
Please excuse me from NOT posting this in the carb area. nobody has posted there since March But I'm prepping the Blast for a WB e-series pipe. Doing the prerequisite 170 main/45 pilot and was wondering if anyone has exposed(drilled out) the air mixture screw and/or made any air box mods. worthwhile?????? I've got the K&N coming with the pipe. Am I missing anything? Thanks, dp new to 'dis blast stuff | ||
| Aikigecko |
Sorry Doug....I'm awaiting a breather for my Blast. Once I have it I'll be terminating my Airbox in it's entireity. We can't wait. Nope haven't done anything to the airmix screw. as before photos to follow once it's finished. | ||
| Chadrat |
Has anyone tried replacing the carb? I took my blast in for the first schedule maintenance. The blast mechanic was really excited that I put a pipe on it. He is thinking that if we put on a new carb with an accelorator pump that we can get it to go faster. He is also thinking of using half of a sportster cam. He has a bunch of ideas and wants to use my bike as a test bike. I might get some free parts out of the deal. | ||
| Buellzilla |
How you doin? Everybody's talking about the K&N air filter, but the K&N website doesn't list anything for the Buell Blast. Where do you get these things? Thanks in advance! | ||
| Buellzilla |
Here is some pics of the Crankcase breather system. Enjoy J   | ||
| Buellzilla |
Here is an incomplete list of Performance Parts for the Buell Blast K & N Air Filter (replaces stock filter) BU5000_________________$53.00 Available from Motorcycle Accessory Warehouse: P/N: (10318) $52.95 K&N Stock Air Box Filter Buell #BU5000 Vance & Hines Slip-On Exhaust P/N 16535__________$199.00 Available from Motorcycle Accessory Warehouse: P/N: (17580) $174.95 Vance & Hines SS2R Slip On Aluminum Buell #16535 Bubs Exhaust P/N 05-1242B Buell Blast System Retail Price: $195.00 You can order by e-mail or call at: E-mail us at bubent@bubent.com Call us at: 1-800-934-9739 Fax us at: 1-530-477-7489 White Brothers; P/N: 05262_________________$259.95 Kerker for Blast P/N: 123-70500_____________$198.95 Jet Kits DynoJet for Blast '00-01 Stage 1 Kit # 8111________$94.48 Available from CAS4 P/N: DS 290348_______________________________ $85.95 Vance & Hines '00-01 Stage 1 P/N:22831__________$94.50 Oil Filter HD P/N: 63806-00Y | ||
| Sarodude |
Does anyone know if the stock Blast carb vents the float bowl to the atmosphere or the airbox? I assume that, at least on the California models, all vents go to the airbox. Please educate me! -Saro | ||
| Buellzilla |
Hey Sarodude; I was able to deduce from the service manual that the carb vents to the airbox through the venturi ring on the inlet. It's the top left hole if you have the airbox cover off and are looking at the air horn of the carb. | ||
| Aikigecko |
Saro, Buellzilla is correct. This pecadillo of the CV Carb is what makes it so hard to make an aftermarket intake for the Blast. | ||
| Sarodude |
There's more than one way to look at the carb scenario... Since it all vents to the venturi ring, it would seem like a good candidate for anyone trying to set up a ram induction system. One of the problems with any kind of forced induction is making sure that you don't start running lean because of (relatively) higher pressures in the Venturi vs float bowl pressures - which sometimes see atmosphere no matter what. Maybe the thing to do is to look at it as some sort of blessing... -Saro | ||
| Aikigecko |
It doesn't vent into the Venturi ring it vents into a hole in the outside edge of the carb face. Anything you want to bolt on has to have a duct in/on it to filter any air coming/going from the float vent. Look at the elbow from a Sidewinder there is a little bump at about 11:00. I went this route trying to make a flange before finding (thanks to another person on this board) a spacer from Kuryakyn that can act as a flange. I'll be setting up my Blast to run it's filter in a dirt-track manner | ||
| Buellzilla |
This is all new to me, but it appears that the float-bowl-vent passage goes straight through the venturi ring and being positioned so close to the edge of the venturi inlet shouldn't see much of any vacuum at all. It seems to me that this design would help insure that the pressure equlibrium is maintained. This is probably what you're both trying to say right? I just had to put it into my own words to understand it. Well, now I know what that hole is for (Oooh, I feel a doorway to raunchy humor opening.) Thanks for bringing it up Saro. | ||
| Aikigecko |
Buellzilla, You got the idea...I'll leave the Hole opening for someone else. | ||
| Sarodude |
OK, I've GOT to ask this... What's in a jet kit? What pilots / mains? What else? Can a handful of jets really be $90? Jets for the Mikuni TMX on my shifter kart are around 3 or 4 bucks... -Saro | ||
| Sarodude |
OK, so I got a DynoJet Jet Kit (along with the V&H pipe) for my wife's Blast. Hmm.... 2 drill bits, a spring, an emulsion tube, an adjustable needle, and a bunch of main jets. Oh yeah, instructions... What's different about the emulsion tube? The needle (aside from adjustability)? The spring? I don't have the carb apart yet. The instructions are actually what I might have a problem with. "*Due to the design of this motorcycle, when changing either the exhaust or the airbox, it is necessary to lean out the main jet." Seems to contradict everything everyone's saying on this board. I can understand running a smaller jet with exhaust changes since the exhaust changes the way the motors 'pulls' on the carb. However, going to a less restrictive airbox or air cleaner would result in less vacuum - and a leaner mix. I have no experience jetting 4 strokes. Strictly a 2 stroke guy, so I'm at a teeny bit of a loss... -Saro | ||
| Buellzilla |
Saro, I'm also at a loss as to what they mean by "lean out". From everything I've read, the best results seem to come from using the 170 main jet. | ||
| Fssnoc2501 |
Saro, I was not only confused by the instructions to use a leaner jet, but I found by my testing that to stay the same or slightly richer was the answer. Please bear with me because this post may be rather long. 4-stroke vs. 2-stroke Ther isn't alot of majic between the two. You must SUCK the fuel in, SQUEEZE (compress) that fuel, BANG (ignite) that fuel, then BLOW (exhaust) the byproducts. This is why I like 4-stroke singles if you idle slow enough you can hear each of these happen. "Suck, squeeze, bang, blow that what makes my thumper go" one of my favorite FSSNOC T-shirts. My experience with 2-strokes is that they have to do all of the above but since they have to complete this process in half of the strokes are much more finicky about carboration. Dyno-Jet, Again, I disagree with the main jet that they suggest. I set my Blast using the age old test of checking a plug reading (I'll discribe this in a bit). With the Kerker pipe I found that a 165 main jet and the air/fuel misx set at 2 turns out from lightly bottomed. When I removed the airbox and installed a K&N filter dirt track style, I found that I needed a 170 with the air/fuel mix at between 2 1/4 and 2 1/2 turns. Thus far I haven't had a fowled plug and have a significant increase in power. The throttle spring is wound alittle tighter than stock and the drilled hole in the slide creates better throttle response along with the tighter spring. Other than the main jet I followed the included instructions exactly. Plug Check, This is for the few of us not blessed a readily available dyno. You need to maintain a set throttle position and speed (I like for the Blast about 3/4 throttle in 4th gear for about 1 - 1 1/2 miles) then you have to grab the clutch and kill switch at the same time. If you allow the engine to even turn over even once the plug will not give you a proper reading. A perfect reading is a plug that is that looks a medium brown. Mine tends to be closer to a dark brown, but I feel it is much safer to keep it alittle rich than lean. My experience is that you will need to take with you a 5/8" wrench a fairly heavy pair of leather gloves and some antiseize compound (I apply alittle to the threads of the plug everytime I have mine out). Altitude, These settings have worked very well for me, but may require some adjustment depending on the altitude that you are at. Home for me in the flat-lands of Kansas is 1200 feet. If you happen to be lower (I doubt you can be very much  ) then you might have to go richer, and if higher may have to lean out a bit. Hope this is of value, Ray | ||
| Sarodude |
Ray- So you have the Kerker... Can you do me a monstrous favor and measure the lengths of the pipe? I'd be looking for: * Length from beginning of pipe to end of 'resonating chamber' - the part that runs parallel to the muffler * Length from beginning of pipe to the center of the hole in the beginning of elbow (?) * Length from beginning of elbow to beginning of muffler Inside diameters would be nice too! As far as plug chops go, I'm not entirely sure what the value would be in part throttle or street environments given the huge variety of conditions one runs in. Plus, I don't know that the 1 + miles is necessary. At least on full throttle runs, we pretty much just pull hard through the gears (usually from a 2nd gear corner), 'chop', and coast into the pits. The chop happens somewhere between 4th and 6th gears - ideally 6th. On a race motor it's easy since you only transition through part throttle and that's easy enough to get right by feel - since you're mainly trying to control driveability and not mileage or anything. Chop and read plug, piston crown, and pipe for WOT and use Ass for part throttle. Of course, that's on a high strung 125 2 stroke... I have an accelerometer based 'dyno' (not a GTech) that needs to be hooked up to a laptop to do anything. I might stick that on my bike and put the laptop in a backpack and go do some testing. Of course, this will all have to wait for me to re-break-in the motor... which can't happen until after I get the bike back...  unless I use Da Woman's bike... Also, if anyone has measured the distance from the exhaust valve face to the end of the exhaust port, that would be cool. I guess I'll have the opportunity to do that soon enough, though. -Saro | ||
| Fssnoc2501 |
Saro, Kerker, 1 3/4" O.D. Main pipe 23 1/2" to center of resonance pipe, 39" total length, Resonance pipe 6 1/2" the muffler 8" overall. I.D. it's 102 degrees outside dude. The only thing that I don't like about the Kerker is the 4" diameter muffler. With the Blast spongy suspension and my lead behind it drags occasionally. Although when I finish dragging the bottom out of the thing, I'm going to replace with a 3" supertrapp. Plug Check, Ya when I was racing flat track on a Hodaka (jess that dates me ) My plug check was done the way you discribe. But with the Blast and its vacuum carb, the main jet working between 1/4 and WOT then with the riding that I do generally (other when I get a wild hair ) I feel that 3/4 is adequate. The distance 1 mile is also to copy closer to actual riding conditions. My only dyno that is readily available is the seat of my pants. Although with the mods that I have made it feels like I have made significant strides. (the seat of pants factor is too cool now ) Ray |
