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Pro X 99101-357 Series Keihin Hex Main Jet

Fits Your MachineDisplaying parts for your 2017 YAMAHA YZ85
Pro X 99101-357 Series Keihin Hex Main Jet
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Pro X 99101-357 Series Keihin Hex Main Jet

Fits: 2017 YAMAHA YZ85

125998

Our Price: $2.24

MSRP: $2.63 - You save $0.39 (15% off)

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  • 99101-357 Style.
  • High quality aftermarket jets for Keihin carburetors.
WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

Pro X 99101-357 Series Keihin Hex Main Jet Reviews

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4.9 / 5.0
184 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
167
13
3
0
1
Value
5.0 / 5
Performance
5.0 / 5
Recommend it?
Yes (76)
No (1)
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
Great product
Great product great value great price. Used in a kx450 carburetor rebuild
April 4, 2020
Washburn , TN, US
Age: 25-44
Purchased
1 month ago
Gender:
Male
Weight:
221 - 250 lbs.
Height:
6'1 - 6'3
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
FCR carb jets
Used to successfully tune the bog out of a 2005 CRF250X.
March 9, 2020
Campbell River , BC, CA
Purchased
2 months ago
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
Good fit and lots of choices.
When I purchased my bike last year it did not run well at my altitude. I did lot of chasing around trying to get a good combination of jetting to get the bike running well. I got a variety of jets and these work great, just don't overtighten them as they are soft brass.

-m-2012 HONDA CRF450X--
March 6, 2020
PRESCOTT, AZ, US
Age: 45-64
Purchased
1 year ago
Gender:
Male
Weight:
191 - 220 lbs.
Height:
5'10 - 6'0
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
ProX jets
Quality part. money well spent!

-m-1994 SUZUKI RM250--
March 2, 2020
claremont, NC, US
Age: 45-64
Purchased
3 months ago
Gender:
Male
Weight:
221 - 250 lbs.
Height:
6'1 - 6'3
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
OEM?
Just like the oem main jet with a much better price

-m-2008 KAWASAKI KLX450R--
February 25, 2020
Dayton , NV, US
Age: 45-64
Purchased
3 months ago
Gender:
Male
Weight:
191 - 220 lbs.
Height:
5'10 - 6'0
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
Worked just fine
Fit like it was supposed and worked just fine. No complaints

-m-1998 HONDA XR250R--
February 25, 2020
Shelley, ID, US
Age: 25-44
Purchased
9 months ago
Gender:
Male
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
Worked as intended
Great fit and value for non oe carb components, looks and fits exactly as keihin parts.
February 4, 2020
Kawartha lakes, ON, CA
Age: 25-44
Purchased
4 months ago
Gender:
Male
Weight:
131 - 160 lbs.
Height:
6'1 - 6'3
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
Pro X quality
Pro X is the only aftermarket jet I would trust. Made in Japan. Identical to OEM Keihin
January 7, 2020
Battle Ground, WA, US
Age: 45-64
Purchased
9 months ago
Gender:
Male
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
New jets
Always need jets around. Living in Michigan it is something you change with the seasons or you have a bike that runs like crap 3/4 of the year.

-m-2001 YAMAHA WR426F--
January 3, 2020
Whitehall, MI, US
Age: 25-44
Purchased
over 4 years ago
Gender:
Male
Weight:
221 - 250 lbs.
Height:
5'10 - 6'0
Value
5 / 5
Performance
5 / 5
Recommend it?
Yes
Awesome
Awesome quality main jet, would buy again! Great product
November 27, 2019
Ottawa, IL, US
Purchased
6 months ago
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Rocky Mountain ATV/MC gift card Each question or answer submitted enters you into a:
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Browse 17 questions Browse 17 questions and 27 answers
I have a 04 yz 250, with a 182 main jet and a 50 pilot jet. When a bought the bike from the second owner with these Jets and it was rebuilt with a wisco piston rebuild kit and a fmf gnarly pipe.. since I purchased the bike I have put a pro curcuit platnum series pipe and v force 3 reeds without re jetting the keihin carb.. is there any suggestions on how many sizes to move up in the main or pilot jet? I live in Whittier CA, altitude 367' and have a few spots that I ride at.. glamis, Ca 335' altitude, gorman Ca, altitude 4160 . Stoddard wells, Ca ., Not sure the altitude but researched online and it says the elevation is 2,800-5,000'. If I can make the bike run and perform properly in the conditions that I ride the bike in then I will be happy. If there is any information any one can give me about my situation as far as re jetting my 04 yz 250 I would greatly appreciate it. I am a new rider but am extremely interested in learning about my bike and being able to tune and repair my own machine so I would dearly appreciate any comments or concerns of my situation. Thank you
Nicholas R on Sep 3, 2017
BEST ANSWER: Jump to a 190 main, keep the pilot the same. Start with a fresh spark plug so you can read the burn on the plug. You will want to run it through the powerband once it is warmed up and notice if you have any bogging out from 1/4 to half throttle. If you do then you will need to also move your needle one clip down so that it richens up the mid range as well. Once you get to full throttle, hold it open for a few seconds and then kill the ignition so that you preserve the full throttle burn on the spark plug. Pull the plug, it should have a nice tan color on it, darker tan the better. If it is white at all or cuts out on power at the top then keep stepping up in main jet increments of 5. If the plug is black and sluggish then bring down in increments of 5 until the plug is a nice dark tan color at full throttle burn.
Have a o6 yfz 450 with a Yoshimura full exaust and a aftereally market intake . How much bigger than stock do I need to go on jet size?
A shopper on Dec 17, 2016
BEST ANSWER: Save yourself the headache and only go up 1 jet size at a time. This jets are fairly inexpensive so I usually buy 2-3 spanning the range I need along with some extra spark plugs to jet any modified bike. Remember your main jet primarily affects 3/4 to full throttle. For better throttle response be looking at your pilot jet and needle position. I hope this helps.
anybody have a guess on jet sizes for a 2005 250exc 4 stroke that usually is run at about 6000-7000 ft.?
A shopper on Sep 3, 2016
BEST ANSWER: to make it run properly you have to count outside temp humidity elevation
generally speaking more elevation smaller the jet i would recommend 2 sizes smaller then stock
beside the mail jet you will have to adjust needle position or buy a jd kit it has everything you need plus great tech support
I have a 2006 YFZ450 with only an intake with an airbox. I’m coming from elevation down to sea level and would know what a good main and pilot would be? Thanks!
A shopper on Nov 24, 2019
BEST ANSWER: Unfortunately, I can only give a rule of thumb guess not knowing what the current tune up is and how far down in altitude you are going. I would start with one step up with both pilot and main and maybe drop the clip down on the needle one groove. Open the a/f screw a half turn and check the float level as specific gravity changes some. This is assuming the tune up was changed from sea level in the 1st place. If you can get the owner's manual or already have it, it should give you an idea of what the standard tune up is. Good luck.
looking for some support on my Suzuki rm250 carb keihin pwk 37E1 KHP i have low end that sputters on 1/4 throttle ,just applied new jets low at 50 hi jet 170 float check out good parallel with casting line , air screw turned out 1 full turn ,can anyone shed some light on the low end spuddering ?
Michael G on Apr 1, 2018
BEST ANSWER: I would try do go down a size on the pilot jet. They say the pilot only controls up to 1/3 throttle but personally I would do that first. Second would be a needle adjustment but one notch on the clip will have a larger impact than going down a size on the pilot which is why I suggest the pilot first. This is assuming your bike is sputtering rich. Make sure of that first, if you were lean it would be more of a hesitation than sputtering so just be sure of that. I never had a RM so I’m not sure of base line jetting but I did do my fair share of jetting. Remember, only make one change at a time and test it at full operational temperature before making another change. Be sure to have a clean air filter as well, that would be a problem itself. Good luck.
What main and pilot jet do I need in my 2003 400ex? Specs: UNI air filter (usually run the box cracked open), LexxMXe pipe with race tip, and I usually ride altitude around 1000ft in Minnesota. Stock jets are 148 main and 38 pilot. Thanks a ton!
A shopper on Oct 31, 2017
Pro X 99101-357 Series Keihin Hex Main Jet
Pro X 99101-357 Series Keihin Hex Main Jet
Pro X N424-26 Series Keihin Pilot Jet
Pro X N424-26 Series Keihin Pilot Jet
BEST ANSWER: There isn’t a set jet size for all applications. It’s a trial and error determination. Buy the next next 3 sizes up for both and try each one to see. Will have to move up in set side for sure. Also adjust fuel/air screw. Needle position.
I have a 2008 ktm 505 that cuts out on the low end I ride between 6500-8500 above sea level but I can not for the life of me find a chart can anyone tell me what size jets I need to run? Thanks in advance!!!!
samual L on Jun 20, 2017
BEST ANSWER: Jet Correction Chart ...... Example: 160 Stock Jet x 0.89= 142 Main JetAltitude - Meters0m500m1000150020002500300035004000Altitude - Feet0'1500'3000'4500'6000'7500'9000'10500'12000'Temperature -22F [30C]1.041.031.011.000.980.970.950.940.93-4F [20C]1.031.021.000.990.970.960.950.930.9214F [10C]1.021.010.990.980.960.950.940.920.9132F [0C]1.011.000.980.970.950.940.930.910.9050F [10C]1.000.990.970.960.950.930.910.900.8859F [15C]1.000.990.970.960.940.930.920.900.8868F [20C]1.000.980.970.950.940.930.910.900.8886F [30C]0.990.970.960.940.930.920.900.890.88104F [40C]0.980.960.950.940.920.910.900.880.87123F [50C]0.970.960.940.930.920.900.890.880.86Locate temperature and elevation on chart aboveTo get correct main jet and idle jet size, multiply the STOCK jet by the correction factor.Needle positionCorrection FactorJet Needle Position.90 and belowLower needle 2 clip positions from stock setting.91 to .95Lower needle 1 clip position1.03 and aboveRaise needle 1 clip position
I have a 06 yfz 450 with a Yoshimura full exaust and a velocity intake what jet size is recommended?
Calvin G on Dec 17, 2016
BEST ANSWER: Hard to say without knowing where you live (weather, altitude, etc). 168 or 170 would be a good starting point.
Have a 06 yfz 450 with full Yoshimura exaust and a velocity intake what jet size is recommended?
A shopper on Dec 17, 2016
BEST ANSWER: I would call Yoshima and tell them what you have. they should be able to suggest a starting point larger than stock
Standard trial and error till you get the right jet for your riding style. i.e. get on your bike warmed up; get into 2nd or 3rd gear and open the trottle (full open) for about 5-10 seconds; immediately hit the kill switch; pull the spark plug and see what color it is; white= too lean/bigger jet needed, sooty black= too rich/smaller jet needed; golden brown is just right/correct main jet. Hope this helps
i have an 05 honda crf230f and i normally ride at about 1000 ft above sea level. what size jets should i use?
A shopper on Apr 13, 2020
BEST ANSWER: Unfortunately, since there are many things to consider while rejetting your bike, we recommend to look through your owners manual or contact a mechanic for recommended jet sizes.
i have an 07 crf 450r that im putting a cylinder works big bore kit and stage 2 hot cam on, do i put a bigger jet and pilot jet in? if so how much bigger?
Kyle F on Jan 3, 2020
BEST ANSWER: Unfortunately we cannot recommend jet sizes, Sorry for the inconvenience.
hi I have a crf 150rb with a fmf power core 4 and a 159 big bore do you know what new jets I need? thx
Hollie A on Sep 3, 2019
BEST ANSWER: Jetting is going to change depending on the aftermarket parts you have on your machine, the elevation and temperature you ride in. There in not a specific guide that will give you the exact jets needed. I would suggest ordering a few and testing them.
Need the suggested jet size for 2012 CRF150F riding at elevations around 7000-8000 ft? (stock is 95)
kevin b on Aug 21, 2019
BEST ANSWER: We do not have jetting recommendations, I suggest buying a couple different sizes and test and tune for the best results.
I have a 2009 ktm 105sx. It’s been a disaster and I am fouling plugs and it runs then doesn’t run. What jets are recommended as a place to
Start? I am at sea level and around 60-80degrees f temp
Marina A on Aug 7, 2019
BEST ANSWER: I pulled the KTM dealer site and show stock jetting is 55 idle jet (54531607055), Starter Jet 85 (54831051085) and Main Jet 200 (54531623200).

I would suggest ordering: JD Jetting Jet Kit Fits: 2009 KTM 125 SX Part# 1112690013 | Mfg Part# JDKH01. The JD jetting kit states: Developed and tested from sea level to 12000ft elevation.
Does this jet fit a 2005 Honda TRX450r?
A shopper on Mar 17, 2019
BEST ANSWER: Yes
Any way to get this jet in 122 size? That's what pro circuit calls for on my bike.
A shopper on Mar 17, 2017
BEST ANSWER: I looked into this and unfortunately we do not have a size 122 in the Pro X brand but we do have two options in the Keihin brand. Part number 1272270027 and part number 1493570036.
Just rebuilt carb on 2003 yz450 f w/ all balls kit . Have full drd exhaust. Popping after let off throttle now. Have been told to go up to a 168 main n 48 pilot . Does this sound like could help ? Ride in ok so no elevation to speak of.
A shopper on Apr 1, 2020
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