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Author Topic: Jetting changes.......  (Read 4084 times)

dewjantim

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Jetting changes.......
« on: November 04, 2007, 05:48:19 PM »
Any of you out there want to add an open exhaust and K&N pod airfilter to free up a couple of hp? Need to know about jetting changes? I used a 130 main and 30 pilot jet to rejet my carb. It runs great and picked up about 5 miles per hour on top and about 15-20 mpg. First time I ever upjetted and got "better" mileage......Dew.
If it hurts, you're not dead yet!!!!!

cyrusb

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Re: Jetting changes.......
« Reply #1 on: December 06, 2007, 09:42:25 PM »
Same here, where did you set your needle? Kept mine in the middle. The transformation my bike had after that mod was unbelievable! Like I've said before, my bike in stock form was downright dangerous to ride.

BanditRE

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Re: Jetting changes.......
« Reply #2 on: December 07, 2007, 01:29:26 PM »
Interesting, thanks guys. That is one of my planned changes this winter. Take off the PAV, add an older pipe that has no cat converter in it and rejet it. Not looking to make it a speed denom, just get it running like it was originally designed for. I'll keep your jet sizes in mind. Hey Dew, what pipe did you put on your bike? I guess the more open the exhaust, the larger jets you need.

First time I ever upjetted and got "better" mileage......Dew.

My Bandit 1200 was horribly lean when I got it, I upsized the pilots, and opened the air screws and the mpg went up as well. I guess if it runs better and smoother, you keep your right hand off the loud handle, which results in better mileage.
2007 Military. It needs some company now the Suzuki has left the stable..........

LotusSevenMan

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Re: Jetting changes.......
« Reply #3 on: December 07, 2007, 09:52:30 PM »
DJT
I have just done the new header and short sliencer with no PAV etc. I want to retain the std circular filter in the rhs tool box though. Would you just keep to the std jets and 'play' with the air bleed screw or go the 130 and 30 jet route anyway?
If it ain't broke-------------------------- fix it 'till it is!

Royal Enfield Miltary 500cc  (2003)
Honda VTR FireStorm (SuperHawk) 996cc 'V' twin
Kawasaki KR1 250cc twin 'stroker
Ducati 916 'L' twin

royalrider_cj

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Re: Jetting changes.......
« Reply #4 on: December 07, 2007, 09:58:50 PM »
After following your suggestions (especially jetting) in this and previous posts, I achieved similar results with my Bullet Sixty-5.  I am totally happy with its performance.  Thanks for your help, Dew.

Charlie
2006 RE Bullet Sixty-5
1971 Suzuki T250R

Leonard

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Re: Jetting changes.......
« Reply #5 on: December 08, 2007, 02:13:03 PM »
DJT
I have just done the new header and short sliencer with no PAV etc. I want to retain the std circular filter in the rhs tool box though. Would you just keep to the std jets and 'play' with the air bleed screw or go the 130 and 30 jet route anyway?

If you are keeping the stock air filter and 130 main will probably be too large.  I would start with a 120 and maybe even a smaller pilot jet.  The air bleed screw is only for idle and just off idle, the size of the main shouldn't matter.
Here is something I found useful on this subject:  http://www.motorcycleblog.org/bulletblog/afterexhaust.html
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http://www.romeoriders.com

eae0164

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Re: Jetting changes.......
« Reply #6 on: December 09, 2007, 03:10:12 AM »
Leonard,
   Thanks for the great link. I've been wary of messing with the jets, fearing I might screw something up, but that page has easy to understand instructions. I guess now I'll have to buy a freer flowing exhaust, and a K&N airfilter...oh, well, off to order the jets.. ;D
2000 RE Military model

LotusSevenMan

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Re: Jetting changes.......
« Reply #7 on: December 09, 2007, 11:16:24 AM »
Well with just the silencer/muffler and header pipe change (+ dumping the PAV) I played with the settings. The air bleed is now set at about 2.1 turns out. The choke needs to be used for a bit more than it did but not an excessive amount IMHO. I have advanced the timing a bit too.
Bike goes much better and although I have only done about three miles on it (weather here is constant bl%dy rain it seems with actual deep puddles forming on the grassed area in the garden!) it goes FAR better. Really pick up well and has a good solid thumpy idle.

Need to try it for a long run plus a plug chop, but very happy with it so far.
PS Surely that large pancake filter has minimal 'drag' on airflow even allowing for the distance travelled to the carb? I prefer the hidden look to the aftermarket ones ya see.
If it ain't broke-------------------------- fix it 'till it is!

Royal Enfield Miltary 500cc  (2003)
Honda VTR FireStorm (SuperHawk) 996cc 'V' twin
Kawasaki KR1 250cc twin 'stroker
Ducati 916 'L' twin

LotusSevenMan

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Re: Jetting changes.......
« Reply #8 on: December 12, 2007, 08:22:45 AM »
Update:-
Some appropriate jets ordered from 'my' UK main purveyor of such RE parts!!!
Should be with me in a couple of days. Weather temp here (as I have no garage/workshop so all done under a blue/grey sky or a temporary Gazebo if raining) is 35*F @ the moment during the day so job may need to be put off for a bit!!!!!!
If it ain't broke-------------------------- fix it 'till it is!

Royal Enfield Miltary 500cc  (2003)
Honda VTR FireStorm (SuperHawk) 996cc 'V' twin
Kawasaki KR1 250cc twin 'stroker
Ducati 916 'L' twin

dewjantim

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Re: Jetting changes.......
« Reply #9 on: December 12, 2007, 08:51:44 PM »
Interesting, thanks guys. That is one of my planned changes this winter. Take off the PAV, add an older pipe that has no cat converter in it and rejet it. Not looking to make it a speed denom, just get it running like it was originally designed for. I'll keep your jet sizes in mind. Hey Dew, what pipe did you put on your bike? I guess the more open the exhaust, the larger jets you need.

First time I ever upjetted and got "better" mileage......Dew.

My Bandit 1200 was horribly lean when I got it, I upsized the pilots, and opened the air screws and the mpg went up as well. I guess if it runs better and smoother, you keep your right hand off the loud handle, which results in better mileage.
I used the stock pipe with the goldstar muffler. My pipe doesn't have the ugly air fitting the newer pipes have so I stuck with it......Dew.
If it hurts, you're not dead yet!!!!!

dewjantim

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Re: Jetting changes.......
« Reply #10 on: December 12, 2007, 08:52:47 PM »
Same here, where did you set your needle? Kept mine in the middle. The transformation my bike had after that mod was unbelievable! Like I've said before, my bike in stock form was downright dangerous to ride.
I left my needle in the stock position, didn't even take it out of the carb....Dew.
If it hurts, you're not dead yet!!!!!

dewjantim

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Re: Jetting changes.......
« Reply #11 on: December 12, 2007, 08:55:56 PM »
DJT
I have just done the new header and short sliencer with no PAV etc. I want to retain the std circular filter in the rhs tool box though. Would you just keep to the std jets and 'play' with the air bleed screw or go the 130 and 30 jet route anyway?
Using the stock air filter you will probably be able to get away without jetting. Adjusting the air bleed screw may be of some help, but you may also have to fool around with the needle jet. Maybe raising it a notch or two to richen the mixture some......Dew.
If it hurts, you're not dead yet!!!!!

LotusSevenMan

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Re: Jetting changes.......
« Reply #12 on: December 14, 2007, 06:33:18 PM »
Thanks Dew.
Well I bit the Bullet (well you know what I mean!) and those three new jets/emulsion tube/parts arrived from a certain UK supplier so Ill do this job at the w/e; weather permitting!!!  ;D
If it ain't broke-------------------------- fix it 'till it is!

Royal Enfield Miltary 500cc  (2003)
Honda VTR FireStorm (SuperHawk) 996cc 'V' twin
Kawasaki KR1 250cc twin 'stroker
Ducati 916 'L' twin

LotusSevenMan

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Re: Jetting changes.......
« Reply #13 on: December 15, 2007, 05:47:00 PM »
The parts arrived in two days!
I started work on 'Harry' and discounting the time to clean and polish the external of the carb the job took in total........................................... 15 minutes!!!!
Amazing how simple the whole thing is to dismantle and reassemble eh?  :o

Well, how did it go? Temp here went up to nearly 4*c above freezing so went out for an eight /nine mile quick test. Much better acceleration with good long time idle-to-drive pick-up etc. Air bleed screw ended up set 2.1 turns out. Needle on std as dismantled position. Idle very steady and slow. Kept thinking it'd stopped.
Header pipe went a nice very light golden colour while hot during and right after ride. Bike is now showing about 5-7 more miles per hour for the throttle in what I'd call its 'happy position' ; if you know what I mean. Almost like a sprocket change. Nice torque and thump too.
Good move those changes!!!!!!!  ;D
If it ain't broke-------------------------- fix it 'till it is!

Royal Enfield Miltary 500cc  (2003)
Honda VTR FireStorm (SuperHawk) 996cc 'V' twin
Kawasaki KR1 250cc twin 'stroker
Ducati 916 'L' twin