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TOPIC: Re:Carb set up help
#974213
bomber737 (User)
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Re:Carb set up help 1 Year, 8 Months ago  
Well i have been running the 177.5 and I have been averaging 37mpg so I decided to try the 180 jet I had. The bike seems to like that one better, with less vibration and a better sound. My mileage also improved to 39.8 yesterday on a 200 mile trip averaging 60 mph. My needle is set at 3.5 so i think on the return trip home i am going to try it at 3 by putting the washer on top of the needle and see what happens. I also set my pms exactly at 3 turns out. It was 2 3/4 before i rejetted.
 
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Last Edit: 2016/06/18 13:02 By bomber737.
 
Why Yes, I have been to the biggest ball of twine in the world
07 RS MIDNIGHT
78,79,80 Suzuki gs1000
89 Suzuki GSX1100F
77 H.D. Sportster
85 BMW K100
89 Yamaha Radian
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#981065
bomber737 (User)
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Re:Carb set up help 1 Year, 6 Months ago  
For the last 4 days i have been riding around the black hills with wife and playing with my carb. I am now running a 180 main jet and i had the needle set at 3. As many of you know going through the black hills out here, on the needles highway and the iron mountain road you are controlling your speed with rpm. I have been trying to keep gear changes to a minimum and just accept the fact i have to run higher rpm sometimes. You are slowing down and speeding up around curves every minute. So i have been running at idle using engine braking and just off idle most of the time. I have discovered at the transition point there is some surging and a slight burble or miss in power delivery.

going out to the devils tower 3 days ago i was able to use wot some and found some hesitation in acceleration. I didnt notice this at the altitude i live at but i am 2000ft higher now. I know i have an altitude compensated carb because its a cv carb but it is noticable here. So yesterday i moved the needle to the 4th grove and took the washer out from on top of the plastic spacer. So now the spacer is sitting right on the c clip. The wot hesistation has gone away but the surging and bucking at just off idle is more pronounced. I am guessing i am now rich at idle and the excess fuel is not flowing smoothly. Its really affecting my driveability. I turned the idle mixture screw in to 2 turns and the engine seems to be happier at idle. Ill see what happens when i go home tomorrow but i am thinking i might go back to the #35 idle jet and see what happens. Any thoughts?

Im getting tired of this carb stuff and im nearing the point of going back to stock.
 
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Why Yes, I have been to the biggest ball of twine in the world
07 RS MIDNIGHT
78,79,80 Suzuki gs1000
89 Suzuki GSX1100F
77 H.D. Sportster
85 BMW K100
89 Yamaha Radian
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#981085
mpersfull (User)
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Re:Carb set up help 1 Year, 6 Months ago  
Have you checked the accelerator pump? You might need to adjust it. There is a tech article on how to do it.
 
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#981121
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Re:Carb set up help 1 Year, 6 Months ago  
bomber737 wrote:
For the last 4 days i have been riding around the black hills with wife and playing with my carb. I am now running a 180 main jet and i had the needle set at 3. As many of you know going through the black hills out here, on the needles highway and the iron mountain road you are controlling your speed with rpm. I have been trying to keep gear changes to a minimum and just accept the fact i have to run higher rpm sometimes. You are slowing down and speeding up around curves every minute. So i have been running at idle using engine braking and just off idle most of the time. I have discovered at the transition point there is some surging and a slight burble or miss in power delivery.

going out to the devils tower 3 days ago i was able to use wot some and found some hesitation in acceleration. I didnt notice this at the altitude i live at but i am 2000ft higher now. I know i have an altitude compensated carb because its a cv carb but it is noticable here. So yesterday i moved the needle to the 4th grove and took the washer out from on top of the plastic spacer. So now the spacer is sitting right on the c clip. The wot hesistation has gone away but the surging and bucking at just off idle is more pronounced. I am guessing i am now rich at idle and the excess fuel is not flowing smoothly. Its really affecting my driveability. I turned the idle mixture screw in to 2 turns and the engine seems to be happier at idle. Ill see what happens when i go home tomorrow but i am thinking i might go back to the #35 idle jet and see what happens. Any thoughts?

Im getting tired of this carb stuff and im nearing the point of going back to stock.



If your still running a fat multi grooved needle, then your lean on the needle. The bucking, is an indicater of lean, not rich. The 180, if its a Mikuni, is actually leaner then stock. The fat needles, and the stock needles are pretty much the same.
If its a fat multi groove needle like a Speedstar, then put the washer back under the clip with the spacer, and go to a 182.5 Mikuni main. If it's a DJ180 main, then your way lean on the main.

Folks generally don't wind these motors up enough. They have enough torque, so folks use it, instead of rpms. Use the rams more like your doing in the hills.
 
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#981393
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Re:Carb set up help 1 Year, 6 Months ago  
Yep its the kury fat needle and im running a mikuni 180 mailn with a #37.5. Ill put the 182.5 back in there and see what happens. Rode 210 miles today and off idle transition is kinda abrupt. If im running lean at idle transition would a #40 pilot jet fix this. Id have to reset the pms of course. The engine is pulling hard all way up at wot, no hesitation with the 180.
 
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Last Edit: 2016/08/05 23:48 By bomber737.
 
Why Yes, I have been to the biggest ball of twine in the world
07 RS MIDNIGHT
78,79,80 Suzuki gs1000
89 Suzuki GSX1100F
77 H.D. Sportster
85 BMW K100
89 Yamaha Radian
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#981431
SKWEARpeg (User)
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Re:Carb set up help 1 Year, 6 Months ago  
The 40 pilot would be a better choice for the 1700, then the 37.5.
As always, make sure your idle is about 900 rpms. It'll be relatively smooth with just a slight hitch in the git up. It won't be potato-potato. Set it when the bike is well warmed up, like right after a ride.
 
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#986119
bomber737 (User)
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Re:Carb set up help 1 Year, 5 Months ago  
I have finally had a chance to do some riding in the last few days after getting back from sturgis. First thing i did when i got back was re-install the 182.5 main. In the kuryakyn directions they say put the needle on the 2nd groove and all you guys say put it in the 4th so i compromised and put it in the 3rd to try it out. The exhaust note is more pleasing now and the popping i was getting at certain rpm's is gone. The engine also runs smoother. It finally pulls hard all the way up to the rev limiter and full throttle roll ons from 70 to 90 are what i would expect from an engine of this size. It accelerates quickly and has more to go. I am finally happy with it. I guess i should have just kept the big main from the get go and saved myself all the headaches and repetative tank pulls. My pms is set currently at 3 1/4. Transition just off idle is much smoother so im going to try 3 1/2 and see how it likes that. Ill prob go to the 4th groove in the future but i am happy with it right now. I am getting 40mpg again.
 
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Why Yes, I have been to the biggest ball of twine in the world
07 RS MIDNIGHT
78,79,80 Suzuki gs1000
89 Suzuki GSX1100F
77 H.D. Sportster
85 BMW K100
89 Yamaha Radian
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#986148
SKWEARpeg (User)
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Re:Carb set up help 1 Year, 5 Months ago  
Step up to the 40 Pilot, and you can turn the PMS back in to around 2 1/2 ish. If you want to try a half step richer on the needle, move the clip to the 4th, and remove the silver spacer, so the fat plastic spacer is all that is under the clip.
 
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#990956
bomber737 (User)
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Re:Carb set up help 1 Year, 4 Months ago  
More playing with the carb today. I put the #40 back in and also installed a 185 main jet. I left the needle on the 3rd groove. The #40 helped with the idle transition and its smoother than before and more manageable in around town traffic. The 185 main did make a difference in the 70mph and above roll on. It has more acceleration and i noticed a very slight hesitation it had before is gone. It accellerated from 70 right up to around 100 to 105 with no problem at wot and would prob keep going. Its getting cold up here in the north so that was good enough for me. I have been chatting with a really good dyno tuner and he auggested i go 2 sizes up on the main since the lean symptoms went mostly away when i installed the 182.5. i also am now getting a solid 40 to 41 mpg. With the 182.5 best i got was 39.5 consistently. Im going to run it like this the rest of the season and maby try a 187.5 in the spring just to see what happens. It cant hurt. I had to set my PMS at 3 to obtain a good reliable idle. So thats the latest installment
 
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Last Edit: 2016/10/22 22:28 By bomber737.
 
Why Yes, I have been to the biggest ball of twine in the world
07 RS MIDNIGHT
78,79,80 Suzuki gs1000
89 Suzuki GSX1100F
77 H.D. Sportster
85 BMW K100
89 Yamaha Radian
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#990999
SKWEARpeg (User)
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Re:Carb set up help 1 Year, 4 Months ago  
I think your still too lean on the needle. The transition is right where the clip position on the needle, counts the most. If the clip is set too lean, then there is a lag waiting for the main to come in. The 40 helped with that. I wouldn't go up any more on the main, unless you run WOT above a hundred, a lot.
If you get the Pilot and clip position set correctly, then you won't have to get into the main as much at cruise(60 to 70). Cruise is all on the Pilot, and just nudging the transition, if it's set correctly. If your lean on the needle, then your opening the throttle just a bit more at cruise.
MIleage is pretty relative to speed and how you ride. I can ride conservatively, and get at least 45. I can get on the interstate, push it up into the 85 to 90 range, and get in the low 30's.
 
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