| Author | Message | ||
     Jordan1200 |
Hi Everyone, I am not a true Buell owner but a wanna be of sorts. I actually own a 1999 sportster with Buell Thunderstorm heads,pistons and SE bolt in cams. (.497) with a SE 7200 RPM ignition module and a SE 1340 air cleaner kit. My carb set up is 45 slow, 185 main a N65C needle with one shim under the hat. I was running SE I mufflers but know I am running stock with the baffle punched and thinking of SE II for a bit better performance. Also I am tossing around the idea of a Mikuni hsr42 but I am wonder if it is worth it. I have a good line on a brand new one that is for a big twin. I had heard read many things on line but wanted the opinions of others with bikes at least something like mine. I live in Ontario Canada near Toronto and we have a wide range of temperature change up here. I like the idea of the many tuning features of the Mikuni and the apparently great throttle response of the Mikuni but I am worried about things l have read about having to adjust it for weather changes and altitude changes if I go o a road trip. One other thing I read was that if you bike tips it could start leaking gas. Advice and guidance welcome ☺ Jordan1200 | ||
| Xldevil |
Actually I own a Sportster with Thunderstormheads and SE air cleaner,SE2 mufflers,SE ignition module and coil (6800)and a well modified CV carb. Have had the SE cams in but while I'm more interested in low rpm torque and cultur,I went back to stock cams. Then I own a Buell M2,running a well tuned HSR 42. The engine is build to 88" since last year and highly modified,but that is another story IFYAM,I would stay with the CV. Maybe it is a little less crisp than the Mikuni,but on a Sportster with its heavier flywheels and its attitude like good old heavy iron,it is not worth the money. For me it gives me all I can expect from a Sportster. | ||
| Buellistic |
"OLD SCHOOL": Product improve your OEM CV and you get the "BEST" of both worlds !!! | ||
| Johnod |
LaFayette have you got any info on that? | ||
| Jordan1200 |
XlDevil I was thinking to go back to my D grind cams. How is it with the Thunderstorm heads? Do you remember what your cv 40 is setup like? Does anyone have opinions on dynojet kits with or with out the thunderslide? (Message edited by Jordan1200 on January 21, 2016) | ||
| Jayvee |
Generally seems two jets are all that's needed, Main jet of about 180, Pilot (slow) jet of around 45. Thats like $10. Dynojet basic kit is like $75? Thunderslide itself gets divided reviews. IMHO probably not as useful as smoothing the sides and bottom of the stock one and maybe a CV spring ($8). Drilling out the slide hole, and shimming the needle, these also have vary whether it gets the desired effect or not. My suggestion, start small (inexpensive) and don't make any permanent modifications until you're sure. Quite a few reports happy with just the 2 jet changes. | ||
| General_ulysses |
PM sent Buellistic. I'd be interested in learning about your CV40 mod. | ||
| Buellistic |
General_ulysses: "ASAP !!!" | ||
| Ebutch |
I have used Mikuni for 12+ years and enjoy much more midrange than the stock carb and less mileage.Advantage no diafram,no butterfly no turbulence caused by butterfly More midrange !!!!!! That's my opinion. (Message edited by ebutch on January 22, 2016) | ||
| Jayvee |
Totally agree, for highest performance, or especially racing, Mikuni without doubt. As far as ease of tuning, the Mikuni is way better. I'm mainly a commuter, with all the rough roads on the commute, I actually like the diaphragm smoothing out the throttle inputs. Sometimes a little matter of money raises it's ugly head too... | ||
| Lakes |
I raced against people that had HSR42, & noticed my 60ft times quicker, but some people like Mikuni HSR42 & say better throttle response . but if a CV is tuned right a Mikuni HSR42 will never beat it out the hole as the CV keeps constant velocity, the Mikuni the rider controls it but would need to roll throttle open slowly so as not to give motor too much air too soon. i did a flow test on my friends flow bench between CV40 & HSR42 both mounted to the same manifold & they flowed same air. | ||
| Buellistic |
"OLD SCHOOL": You can not buy TUNED out of a BOX !!! | ||
| Natexlh1000 |
True dat! There is a reason people get payed money to do this stuff for you. Just because a thing is mass-produced doesn't mean it is identical to every other one. | ||
| Jordan1200 |
Well I couldn't resist the temptation of the Mikuni. If I don't like it I will throw the CV back on. The price was too good the Mikuni up here goes for about 400-500 or so. I got a new one for less. The Dynojet kit up here is 170 for thunderslide kit.and if I was to do it I would do a rebuild and that would be another 150 aproximately so I figured why not it will sell easy for whst I paid for it. (Message edited by Jordan1200 on January 25, 2016) | ||
| Ebutch |
Jordan: You Will Like It !!!!!!!!!  | ||
| Xldevil |
Nobody needs a Thunderslide or Dynojet Kit. But no doubt,the Mikuni is a good one anyway. (Message edited by Xldevil on January 25, 2016) | ||
| Lakes |
Xdevil , i agree!!! i have never liked those kits, & never liked changing CV stock spring or drilling the vacuum hole but have smoothed the flow & changed the needle & have mine set up to take holley carb main jets they go up in one thou increasements also have Woods float bowl so increased amount of gas where it is needed & i use a S&S G manifold with custom adaptor & CV44 carb. it works flawlessly for me always responds no flat spot & very smooth. also have Dyna adjustable ignition module that mounts in stock mounting place. i will be at the track again soon! | ||
| Jordan1200 |
Does anyone know what the stock configuration is for the HSR42 (10-11). The pump nozzle, needle And clip position, pilot and main jet? | ||
| Kc_zombie |
#70 Pump Nozzle 97 Needle (J8-8DDY01-97) No.3 Clip Position 25 Pilot Jet 160 Main Jet | ||
| Renter |
I got a mikuni for my modded block. Responds very fast, Any of you guys have had problems with stuck carb floater. Mine sometimes starts overflowing, have to tap it a bit and then it stops. It happened a few times when on sidestand and i shut engine off. Any pointers ? Regards, Danny | ||
| Lakes |
Renter, can you explain what you mean by , Responds very fast? like is bike idling and you open throttle quick? or is bike traveling say at 3,000 rpm & you open it up full & fast does it respond very quick?? | ||
| Renter |
I got hotter cams and flywheel machined down, stage 3 XB heads. My bike revs like a japanese bike and no stuttering at any point. The throttle response is fast, i am even thinking at installing stronger spring or modify stock throttle because it feels the bike is very nervous, i have to dose the throttle coming out of corners very carefully. If i hit a bump in the road and the throttle opens slightly i pick up unwanted speed fast. I have a feeling the CV was more damped in response, more forgiving with small throttle adjustments due to riding influences. I still have my CV, maybe change it back this summer to confirm difference if i cannot get the mikuni setup to slow down a bit. Have to research if stronger springs are available for the mikuni or change throttle body for longer gas travel. Regards, Danny | ||
| Kc_zombie |
Renter: The CV and slide are two different principals of operation. Some folks use a CV with a Thunder Slide kit to increase the throttle response, but nothing (IMHO) can match the throttle response of the Mikuni. I would love to see a picture of your S1... | ||
| Jayvee |
The term "throttle response" could be describing slightly different things. Could mean either the amount of power felt as the grip is twisted (more mid-range power) or it could be only the immediacy of the reaction of the slide going up when the grip is twisted (hitting a bump moves the throttle) or the amount of position change of the slide reacting to the grip being twisted (I had a DT-250MX when the fad was to put on a 1/4 turn "racing" twist-grip, to "improve throttle response." Engine power didn't change, the carburetor itself didn't change, but the slide reaction changed a lot. I think it was a Mikuni.) (Message edited by jayvee on March 17, 2016) | ||
| Renter |
My bike described in this thread: http://www.badweatherbikers.com/buell/messages/476 23/768757.html (Message edited by renter on March 17, 2016) | ||
| Lakes |
well if your happy thats great!! my friend has a Mikuni HSR42 i have a SE CV44 Bobby Wood 43.5 Rebel with Wood K2 needle Wood changes a lot of things in the carb but NOT the Spring as this is a CV carb to keep velocity up i think opening the carb up faster to allow air in faster just KILL's VELOCITY, if you set a stock CV40 up correctly they perform very well!! but as they come they are on lean side. i have never liked the Thunderslide myself & raced against other Harley powered bikes that used them. i like to use the track to check my performance gains look at 60 foot time & trap speed's 1/4 mile gives me all the info i need. so Renter take it too a track compare trap speeds between a CV40 tuned right could check AFR & change needles & jets to get it close to ideal then do the same with the Mikuni 42, also note the manifold you use very important to air flow gain or loss. then go to the track look at your trap speeds to see what the difference is. my friend would love to swap carb with me. i have stock thunderstorm heads with improved flow via valve seat angles ports cleaned up, stock thunderstorm pistons new rings S&S G manifold 1" spacer machined to fit CV 44 seal Andrews cam stock lift decked barrels to get 40 thou swish clearance D&D race pipe dyna tech adjustable ignition set rev limit at 6,500 but would rev strong past that , just i know what happens when you have those old Male Female rods spinning too fast, when they go it will be that female rod that breaks!! |
