| Author | Message | ||
     Ezblast |
The primary is very important for launching - a very important part to performance - whether at the line or out of a corner - I've tried to keep the needle in the area where both turn lean - thus compensating the right area and no more - where the rich dips begin - the main jet tells the needle where to fall - so I concur - fully there, however there are only two choices for the primary and for most folk the 45 will be fine but if your digging hard into the darkside modifying for power, you'll end up a tad fat with the 48, but more power - there is always the trade off factors - leaner is cleaner, hotter, better mileage, fatter is cooler, less gas mileage, more power - they say the racing balance is 14.5 to 17.5, and modern engines are usually balanced around 14.5 and up, the stock Blast is balanced lean for the EPA, however, to be fair, it was severely tested and held up well, for a very vast majority of owners as well, the boot the only real threat to the motor and a easy fix if in the know for simptoms to watch for - quiet an engineering feat considering the technology used with the price point as a bottom line - That needle could be an adjustable K&N product, or mid 90's era adjustable needle - I forget the number combo - N - 'something' - tried it but didn't like it. EZ | ||
| Gearheaderiko |
I have slow jets 42,44,45,46,48 & 50. No problem getting jets! I guess if I were drag racing all the time, running a plug "that would fire through oil" and wanted to wash my cylinders clean, I'd go rich. Entirely possible that you're also running a unique intake, carb and exhaust allowing the 48 jet. I'd really like to know where your rpms are if you're running slow enough to use your slow jet to pull out of a corner! I'm not seeing that. That doesnt sound fast or fun  Nightrider site: I'm not saying this site isnt helpful. The Nightrider site has tons of info, including part numbers. Its a very good reference guide. I'm in no way saying we cant help you or you should look elsewhere. After all this you'll probably be running 48/175 w/2 shims! | ||
| Ezblast |
LOL - thats true - Ralph pointed that out long ago - I researched it - suggesting the 44 for high altitude and 170 being a good set of jets for the 5000 and above club - lol - I was running the 44 myself but could feel the difference of the 45 with the Dial-A-Jet set at minimum and a 155 main. NightRider gives you a lot of old hotrodder tricks - I have a link to BADWEB carb hotrodding tricks as well up top. Some work better than others on a single. EZ | ||
| Gearheaderiko |
Its a very rare occasion when you havent done your homework on mods! We can just let to the minor differing viewpoints stand.If one truly does the carb work they'll find their own right answer (or preference). Unrelated: Do you know what main jet you'd have to run if you didnt have the DAJ? | ||
| Ezblast |
The DAJ is a funny thing to tune with - without I'd say 165/170 - but I'd have to goose the primary to a 46 in all probability - the DAJ says it guarantees it will prevent a lean condition, even if set on minimum - which is where I have it, and says to jet 1 to 2 jets lower than normal - for a Blast that is more like 3 jets - lol - and easy to tell if the boot is going bad by increased idle - which I like, on the red bike it may be faster idle but usually it is a pop or two that tells me time to change the boot. You get into so much stuff, that you have to review other stuff to remember it - heck I'm still waiting for someone to throw on a DelOrto carb - lol - as for the corner, if you coasted down a set then get to the last turn you can down shift and then shift right back up or you can take it from that 2000 to 2500 area and twist all the way through your powerband - both methods have positives - depending on where your torque delivers the later could be slower - on the Blast it usually starts delivery at 2500 max's by 3500 to 4000 and just hangs near the top after that - I usually ride like that if I'm following traffic where maneuverability is a must and a long space between shifts can be useful, and laziness - lol EZ (Message edited by ezblast on June 29, 2008) | ||
| Gearheaderiko |
Well, if info and parts were more readily available, I'd throw the DelOrto on (its wasted on the ShovelPan anyway)! | ||
| Ezblast |
I had a duel set of 48's on my hotrod bug - easiest duel setup I ever tuned - way easier than the Webers. EZ | ||
| Twisty_mcwrister |
got the air/fuell gauge on! and it looks like my carb is tuned right! thanks to all you guys and gals here! where it turns from yellow to green is 13-1 i believe. here are some pics and a video!    | ||
| Imadreadhead |
what oxygen sensor are you using? | ||
| Ezblast |
Very nice! EZ | ||
| Twisty_mcwrister |
i asked the guy at napa for an 85 injected camaro single wire o2 sensor. basically an old 305 sensor. cost me 22 bucks. the gauge is an auto meter ultra light. if you go to the website you can download a pdf which tells you what ratio the gauge is saying. thanks ez. the mixture is nice due to the info i got here. pretty much stays there unless i blip it hard or roll off at high rpm's. it dips to around 14.5 or so. the setup is 48/175 with the adjustable sporty needle at the 3rd slot from the top. k&n, v&h, and the ez box mod. next is a tach to match the other side of the speedo | ||
| Twisty_mcwrister |
i figure it will also tell me when my boot goes bad, when i'm running out of fuel, or any other air/fuell related changes | ||
| Ezblast |
Bravo! | ||
| Imadreadhead |
yup..im gonna do that now...f'in gauges are too expensive..o well | ||
| Imadreadhead |
did u just find a nut that it screwed into..then had it welded on? | ||
| Twisty_mcwrister |
basically. | ||
| Imadreadhead |
would you happen to still have the part number to the oxygen sensor | ||
| Toniportray |
That sounds like a prowler in the night with the crickets in the background. Nice dash! I too put a small watch there because I like to know how fast I need to ride to get to places on time. Sometimes my commute route gets changed because I see a neat new road to go check out so keeping a clock where I can access it keeps me from running off for too long. | ||
| Twisty_mcwrister |
thanks toni. yeah i wear full gear all the time so its kinda hard to check my watch when its under gloves and a jacket. (zip ties are a motorcyclist's best friend) imareadhead: http://www.partsamerica.com/ProductDetail.aspx?Mfr Code=BOS&MfrPartNumber=12014&PartType=291&PTSet=A the gauge came out of a camaro so i got the sensor to match. not sure if there are different gauges for different cars. (Message edited by twisty_mcwrister on July 02, 2008) (Message edited by twisty_mcwrister on July 02, 2008) | ||
| Dankno |
Jeebus thats brilliant!!! I am so getting one!!!  Does that particular gauge have a dimmer by any chance, the only downside that I can foresee for me, would be riding at night with the lights dancing about like that, talk about target fixation! I'd be riding around all night with the theme from Knight Rider stuck in my head! LOL!!! | ||
| Twisty_mcwrister |
haha. its not that bright. | ||
| Twisty_mcwrister |
the gauge has been proven. after adjusting my tps(and finding out its bad) i didnt tighten one of the hose clamps on the boot enough. the gauge began to run kinda lean, so i checked the clamps and sure enough i got about 1/2 a turn out of it. then it richened back up ! | ||
| Imadreadhead |
my gauge is in the mail...i got an autometer phantom gauge...then im gonna buy a 1 wire universal o2 sensor...then i have to see how much my welder guy is gonna charge me to weld on a bung for the o2 sensor to go.. but hey..thanks for kicking this idea off! | ||
| Twisty_mcwrister |
cool . let me know how things go. | ||
| Toniportray |
Is there any sort of accessible carburetor owners manual that would have detailed information about what effect leaning the mixture would have on performance and fuel efficiency? I understand that just leaning by putting in a smaller main fuel jet might not actually have any significant desirable effect on fuel economy. But if one can get the right air AND fuel jet sizes right, I think significant fuel efficiency increases can be obtained. Any idea if such a publication exists? There's good information here, but I'd love to see some calibration charts or such from the manufacturer if there are any. | ||
| Gearheaderiko |
"I understand that just leaning by putting in a smaller main fuel jet might not actually have any significant desirable effect on fuel economy." Not sure where you got that information, but coupled with the rest of your post, it seems your being misled. I doubt any such publication (for your application) exists and your research should be for 'hypermiling'-driving for fuel economy only. To find such information directly related to your goal with a CV carb is IMHO looking for a needle in a haystack. You best bet is to install and air/fuel ratio gauge or get the bike on a dyno and start tuning. Its amazing what you can do when you can 'see' how every jetting change will affect the A/F ratio. I doubt that anyone will want to 'predict' your A/F ratio when your plan is going to be running on the dangerous side of lean. However, many of the dyno charts from places like K & N, DynoJet, exhaust manufacturers and individuals, etc. may show the A/F ratio and jetting. I'd also install an oil temp gauge and possibly an oil cooler (with on/off or thermostat) so you can keep your engine at optimum running temp without overheating. Better fuel economy can be had by installing an XB head and piston (if my results will translate directly to mpg and not just power). I'm sure there is a small party of Buell/Harley riders that tune mainly for fuel economy, so I dont think you're alone in your endeavors. It just may be hard to find them. | ||
| Ezblast |
concur! | ||
| Reuel |
Every time you double compression, you increase efficiency by 50%. There are a couple different ways to get a significant increase in mileage, but they're fairly exotic. One requires mounting a carburetor that, as far as I know, only exists as a down-draft carburetor. (I have one.) They are not in production, either. The primary target was bigger engines, too, so getting one tuned to work with the Blast would be difficult at best. The second option that I know of is direct injection. It's been available in Japan for years. Ford is starting production of direct injection engines. It works much like diesel where the air intake is always wide open, and power is achieved by increasing fuel flow to an injector that's mounted inside the cylinder. Ford has some variant of this concept. The engine has to be built to withstand extremely lean conditions to keep it from self destructing. (Message edited by reuel on July 24, 2008) | ||
| Ezblast |
LOL - well that isn't the Blast - a simple tear in the boot can do that under the right conditions - and I'm not even referring to my self. EZ | ||
| Toniportray |
Is the stock needle adjustable? What I mean is whether it has the 3 little carved rings that one can select for positioning the washer piece which effects how far the needle probes the main jet (to effect fuel delivery). I am curious whether I saw that on the Blast or my Yamaha. I don't want to open it all up just to check. |
