Mikuni hsr 42 tuning
#1
Mikuni hsr 42 tuning
Gday ive got a 2005 softail ive got s/e 11 pipes breather kit ignition module, coil ive recently added the mikuni but cant get the tuning spot on its got a 160 main 25 slow and 70 nozzle it really seams to bog dowwn either getting to much fuel or not enough when you open it up on the highway around 70 miles
the plugs are sligtly sooty(sign of richness)
and the other day when i got home and turned off the engine there was engine run on (sign of leanness)so im a bit baffles any help would be appreciated
the plugs are sligtly sooty(sign of richness)
and the other day when i got home and turned off the engine there was engine run on (sign of leanness)so im a bit baffles any help would be appreciated
#2
#3
Here is a link to an article written by Joe Minton. He wrote the book on the HSR carb... literally. He wrote the tuning guide (which is available in PDF format on Mikuni's website.)
http://www.americanrider.com/output.cfm?id=1581175
He states that the carbs come a bit rich. He recommends a 17.5 idle jet, a #98 needle (which is slightly leaner than the 97), and a #50 accelerator pump. He says the stock main jet is usually correct (160 I believe?). There is a kit that can be purchased from Fox Distrubuting. I believe the number is in the article. I just ordered the kit from them a while back and they were really great to work with. The person I spoke to really understood the Mik carb as well.
http://www.americanrider.com/output.cfm?id=1581175
He states that the carbs come a bit rich. He recommends a 17.5 idle jet, a #98 needle (which is slightly leaner than the 97), and a #50 accelerator pump. He says the stock main jet is usually correct (160 I believe?). There is a kit that can be purchased from Fox Distrubuting. I believe the number is in the article. I just ordered the kit from them a while back and they were really great to work with. The person I spoke to really understood the Mik carb as well.
#4
#5
Here is a link to an article written by Joe Minton. He wrote the book on the HSR carb... literally. He wrote the tuning guide (which is available in PDF format on Mikuni's website.)
http://www.americanrider.com/output.cfm?id=1581175
He states that the carbs come a bit rich. He recommends a 17.5 idle jet, a #98 needle (which is slightly leaner than the 97), and a #50 accelerator pump. He says the stock main jet is usually correct (160 I believe?). There is a kit that can be purchased from Fox Distrubuting. I believe the number is in the article. I just ordered the kit from them a while back and they were really great to work with. The person I spoke to really understood the Mik carb as well.
http://www.americanrider.com/output.cfm?id=1581175
He states that the carbs come a bit rich. He recommends a 17.5 idle jet, a #98 needle (which is slightly leaner than the 97), and a #50 accelerator pump. He says the stock main jet is usually correct (160 I believe?). There is a kit that can be purchased from Fox Distrubuting. I believe the number is in the article. I just ordered the kit from them a while back and they were really great to work with. The person I spoke to really understood the Mik carb as well.
His recomedation wont work for a bike with a big bore, cams and big exhausts, I have tried!!!
A # 20 pilot was just too small on my 95, (i didnt even try the 17.5 they recomend) hard starting and rough idle.
around LA most bikes with aftermarket pipes are using the #27 pilot.
The fatter needel is doable, but the HQ part works better,
I prefer to keep the stock #70 squirter and raise or lower the main jet size to do the fine tuning.
Trying to run the smaller squirters gave me masive pining on hot days when rolling on the throttle. not to mention the lack of power on acceloration.
I almost forgot to add the best advice ive ever gotten about tuning: regardless of what anyone says, just give the bike what it wants!!!
Last edited by new_mentor70; 01-15-2009 at 10:55 AM.
#6
I'm going to read the article, but I wanted to add to this thread since there are some experienced tuners here.
I have a '96 FXDWG with an Andrews EV3 or EV27 (can't remember now), V&H straight shot pipes, the SE air cleaner, Dyna 2000 igntion (single fire) and an HSR42. All of this stuff has been on this bike for 90k miles, 1997 is when I did the work. I had the cylinders refreshed at about 60k miles, SE cast pistons, nothing radical.
The bike is running rough and idling poorly. I replaced the intake manifold gaskets last year, didn't seem to help. I can adjust the idle speed screw so it won't stall, but after riding it for 45 mins or so, when I stop at a light she's racing. I readjust the idle speed and she's OK for the rest of the day. Next day, hard start unless I tighten the idle speed screw in a couple turns. Then the whole process starts again. Seems to me I should not have to adjust the idle speed so much.
I'm certain the carb has the jets it came with and I know I haven't done anything to them in all these years either. Recently mentioned problem to a shop when I brought it in for a timing check and valve adjust. They told me they leaned it out some. The bike is running the same, not that great IMO. She was Cadillac smooth a couple years ago, but this idle speed thing has been going on for some time.
If it matters, I'm in California, so no high elevation stuff to deal with. I run 91 octane fuel.
Maybe my story will spark a thought from the experienced users here. I'd appreciate any recommendations.
Thanks in advance!
Jeff
I have a '96 FXDWG with an Andrews EV3 or EV27 (can't remember now), V&H straight shot pipes, the SE air cleaner, Dyna 2000 igntion (single fire) and an HSR42. All of this stuff has been on this bike for 90k miles, 1997 is when I did the work. I had the cylinders refreshed at about 60k miles, SE cast pistons, nothing radical.
The bike is running rough and idling poorly. I replaced the intake manifold gaskets last year, didn't seem to help. I can adjust the idle speed screw so it won't stall, but after riding it for 45 mins or so, when I stop at a light she's racing. I readjust the idle speed and she's OK for the rest of the day. Next day, hard start unless I tighten the idle speed screw in a couple turns. Then the whole process starts again. Seems to me I should not have to adjust the idle speed so much.
I'm certain the carb has the jets it came with and I know I haven't done anything to them in all these years either. Recently mentioned problem to a shop when I brought it in for a timing check and valve adjust. They told me they leaned it out some. The bike is running the same, not that great IMO. She was Cadillac smooth a couple years ago, but this idle speed thing has been going on for some time.
If it matters, I'm in California, so no high elevation stuff to deal with. I run 91 octane fuel.
Maybe my story will spark a thought from the experienced users here. I'd appreciate any recommendations.
Thanks in advance!
Jeff
Last edited by tym4brk; 01-15-2009 at 05:22 PM.
#7
Gday ive got a 2005 softail ive got s/e 11 pipes breather kit ignition module, coil ive recently added the mikuni but cant get the tuning spot on its got a 160 main 25 slow and 70 nozzle it really seams to bog dowwn either getting to much fuel or not enough when you open it up on the highway around 70 miles
the plugs are sligtly sooty(sign of richness)
and the other day when i got home and turned off the engine there was engine run on (sign of leanness)so im a bit baffles any help would be appreciated
the plugs are sligtly sooty(sign of richness)
and the other day when i got home and turned off the engine there was engine run on (sign of leanness)so im a bit baffles any help would be appreciated
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#9
Did you read your own thread?
Last edited by new_mentor70; 01-26-2009 at 01:02 PM.
#10
I'm going to read the article, but I wanted to add to this thread since there are some experienced tuners here.
I have a '96 FXDWG with an Andrews EV3 or EV27 (can't remember now), V&H straight shot pipes, the SE air cleaner, Dyna 2000 igntion (single fire) and an HSR42. All of this stuff has been on this bike for 90k miles, 1997 is when I did the work. I had the cylinders refreshed at about 60k miles, SE cast pistons, nothing radical.
The bike is running rough and idling poorly. I replaced the intake manifold gaskets last year, didn't seem to help. I can adjust the idle speed screw so it won't stall, but after riding it for 45 mins or so, when I stop at a light she's racing. I readjust the idle speed and she's OK for the rest of the day. Next day, hard start unless I tighten the idle speed screw in a couple turns. Then the whole process starts again. Seems to me I should not have to adjust the idle speed so much.
I'm certain the carb has the jets it came with and I know I haven't done anything to them in all these years either. Recently mentioned problem to a shop when I brought it in for a timing check and valve adjust. They told me they leaned it out some. The bike is running the same, not that great IMO. She was Cadillac smooth a couple years ago, but this idle speed thing has been going on for some time.
If it matters, I'm in California, so no high elevation stuff to deal with. I run 91 octane fuel.
Maybe my story will spark a thought from the experienced users here. I'd appreciate any recommendations.
Thanks in advance!
Jeff
I have a '96 FXDWG with an Andrews EV3 or EV27 (can't remember now), V&H straight shot pipes, the SE air cleaner, Dyna 2000 igntion (single fire) and an HSR42. All of this stuff has been on this bike for 90k miles, 1997 is when I did the work. I had the cylinders refreshed at about 60k miles, SE cast pistons, nothing radical.
The bike is running rough and idling poorly. I replaced the intake manifold gaskets last year, didn't seem to help. I can adjust the idle speed screw so it won't stall, but after riding it for 45 mins or so, when I stop at a light she's racing. I readjust the idle speed and she's OK for the rest of the day. Next day, hard start unless I tighten the idle speed screw in a couple turns. Then the whole process starts again. Seems to me I should not have to adjust the idle speed so much.
I'm certain the carb has the jets it came with and I know I haven't done anything to them in all these years either. Recently mentioned problem to a shop when I brought it in for a timing check and valve adjust. They told me they leaned it out some. The bike is running the same, not that great IMO. She was Cadillac smooth a couple years ago, but this idle speed thing has been going on for some time.
If it matters, I'm in California, so no high elevation stuff to deal with. I run 91 octane fuel.
Maybe my story will spark a thought from the experienced users here. I'd appreciate any recommendations.
Thanks in advance!
Jeff