I have just got a XR600 87 model. I rode it a couple of times on the road with a K&N air filter. I trashed that one and put on a No-Toil filter. The plug before was dripping and really hard to start. Since then my plug is white, and really pops on decelleration. I pulled the carbs and found it to have a 122 main in one carb and a 125 in the other. The pilot is a 45. I dont know how big to go on jet sizes. :) It has a Super Trapp on it and I live about 3000 ft above sea level. I am not jet crazy but I need to do something. Could someone help me out with my predicament?



Thanks for all the input :)

Your welcome... :) Not to much info on those dual carb models...Dual Carbs...what hogwash that [@#$%&*!] was. I had one and sold it within a month. Not to say they don't run well but why deal with it? I would contact a dealer and find out what stock jets came in those carbs from the factory. Then I would ask them what they reccomend for jetting. I know everyone hates xr's only but they could set you up with some numbers to start with. Give em' a try.

I really hate the two carbs as well. I missed it by one year, the 88 model has one carb and disc brakes. I got mine fixed late last night after taking the carbs and switching jets around 4 times. What a pain in the arse that was. Thanks for your response. :)

Here you go. First thing you need to do whether you own a new bike or an old bike is buy a factory shop manual. The stock jetting for my 85 xr600r is 45 for the pilot jet and 122 for the main jet in the primary carb and the secondary carb. From what you said about your plug color. I think I would definitely go to a 48 on your pilot and put 125 main jets in your primary and secondary carb. But you may also have to adjust your needle position up in your carbs. I can send you the info tonight. I don't have access to the manual at the moment.

I have a 122 in my primary carb and a 125 in my secondary carb. I have a 45 pilot. I finally got it sorted out last night after about 6 24oz KING COBRAS!!!! The needle was third clip from the top on my primary carb and was second from top on my secondary carb. I put my needle position in the third from top on both carbs and put it back together with my air fuel mix screw about 2 3/4 turns and it runs better than ever!!! I am on my way to the Baja in 4 weeks and am really looking forward to a super ride....


Im sorry man, but I cant help much except for a tip to get it fixed asap and dont run it if avoidable because my friends 600 just heat seized from running too lean. you may try a higher heat rated plug for starters tho. -Matt

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