| Author | Message | ||
     Igneroid |
I have a HSR42 Mikuni carb on the Cyclone along with a HBBI intake and now Ive put the Vance and Hiney aluminium can back on even though it sounds like a Yugo with a hole in the muffler. Anyhow, after reading the Mikuni manual, I tried some of their tuning ideas. The roll-off test indicated that the bike was running lean. I put a 165 main jet in, replacing the 160. Now when I try the roll off thing, the bike does not accellerate harder but it doesnt really back off either. Am I still too lean?? The bike pulls waaaaay harder at full throttle now but Im still wondering if I should go richer still....(I have to order jets from far away seein as I live in Buttstain Nowhere) | ||
| Dave_02_1200 |
I have a 2002 with a Mikui HSR 42, Forcewinder intake, and Race Kit pipe. Have you tried raising the needle? That is what made the difference for me. I am using a 165 main jet and the needle is either 1 or 2 notches above the middle position. (lower the retaining clip to raise the needle) Good luck. Dave | ||
| Igneroid |
Ill give that a try Dave. Thanks. | ||
| Italialaw |
Go here: http://www.mikuni.com/pdf/hsr_tuningmanual_021003. pdf Also, with your set up, a 165 seems plenty big, and raising the needle one notch should do the trick. What do your plugs look like? | ||
| Igneroid |
Also, with your set up, a 165 seems plenty big, and raising the needle one notch should do the trick. What do your plugs look like? Thanks for the link(The Mikuni people sent a hard copy of that link in the kit) but I have it already. My plugs had kind of white deposits on them before I re-jetted. They seem to be a very light tan now, almost caucasian skin tone but a tad lighter. It pings at low RPM still as I pull away from a stop if I am generous with the throttle. Others have said that the throttle response of this carb is quick but I dont find that to be the case. Im thinkin the needle raising thing might be the ticket allthough I dont know how much that will help at full throttle. The reason for all this tweekin is Im goin drag racing this weekend(8th mile) and want to do Buell proud.....and not fall off.} | ||
| Buellistic |
Take the guessing out of the picture !!! Put a AIR/FUEL Gauge in the Header Collector ... Then you can ride it down the road in the real world and get it right ... Still running the OEM Carb. on my 1997 S3T and the jetting is Low Speed #48 with a High Speed #200 ... Get your timing correct before you tune the Carb. ... The Carb. tuning sheets never say check the timing !!! | ||
| Igneroid |
Get your timing correct before you tune the Carb. ... I have a timing light and a manual. I'll give that a try but the setup seems like it wouldnt vary from stock(hall effect pickup, no wearing parts).. What is this AIR/FUEL gauge you speak of? Sounds like the cats ass for tuning but Ive never heard of one?? Thx.} | ||
| Buellistic |
Got the parts(air/fuel gauge and exhaust oxygen sensor from J.C.Whitney) and a 02 sensor fitting from Auto Parts Store ... Wired it myself, just use it for tuning Carb. and is not left on bike after tuning is completed ... Set my timing so the timing mark(use static timing method as "i" have a IGN. Module with an LED on it)is just coming into the timing plug hole ... | ||
| Bad_karma |
Percy Sounds like the 165 is good, might think about the 162.5 but you plugs will tell the story. Which needle are you running? Good luck Joe I always close the gap down on the accelerator pump. (Message edited by bad_karma on August 01, 2008) | ||
| Igneroid |
Percy Sounds like the 165 is good, might think about the 162.5 but you plugs will tell the story. Which needle are you running? Good luck Joe I always close the gap down on the accelerator pump. Thanks Joe. Im running the stock needle in the stock position. Im gonna try raising it one notch as suggested here. Ill try adjusting the accelerator pump to open quicker like you. Mebey that will alieviate the pinging. Anyhow, this bike is pulling harder than than it ever has in the last year Ive owned it. Im hoping to cut about a quarter second on my times(8th mile). Seems like alot, I know, but my times arnt that great to begin with...heh... | ||
| Bad_karma |
Percy If you got pinging, you are lean. Don't put the 162.5 in there. If the accelerator pump doesn't clear up the pinging go with a 167.5 Joe (Message edited by bad_karma on August 03, 2008) | ||
| Igneroid |
Percy If you got pinging, you are lean. Don't put the 162.5 in there. If the accelerator pump doesn't clear up the pinging go with a 167.5 Joe Ima lousy splainer. The pinging I was getting was at a generous part throttle lifting from a complete stop. I adjusted the needle up one notch and put zero play in the accelerator pump linkage(it was pretty close but I closed it right up). No more pinging...wahoo!! And throttle response has improved to the point of being touchy I went for a scream to the lake and back last night and the jury is still out on the roll off test. I cant really tell if it accelerates when I roll off quickly. Im thinkin the main is very close. I might order up a 167.5 and give it a try. Anyhow, Im off for two days of drag racing and will see how much time I can shave off the 8th mile. On my first outing in May, my best time was a 8.33(sic). Too much wheely-age. My second time in june was a best time of 8.09. I had a lift strap on the front end. Today or tommorow, with alla this tweekage, Im hopin that this sweet little bike will haul my fat ass down the 8th at around 7.75 at 98 or a hunnert miles an hour... Thanks for all the help.....this thing is getting better all the time.. | ||
| Texas_firebolt |
try raising your needle one notch and going with a bigger spray nozzle. fifty is what i suggest on the spray nozzle |
