Jetting XR630?

Just put a 630 kit throught my 88 XR600 and put a white brothers e series what jetting should I be using???? :banghead:

it will depend on which piston you have used. You can get kits with a compression ratio of 9:1 (same as standard) but some bump it up all the way to 11:1. The larger the piston and higher compression ratio, the richer you'll need to go with jetting as a rule. For memory stock is 60 pilot, 165 main jet, needle 3rd clip position float level 14.5mm on this model. Try going slightly richer changing one thing at a time, each time run the bike for at least 20 mins, whip out the plug and check the colour of the tip. White means too lean, black or dark brown too rich and tan/light brown correct. Good luck.


as a rule is there any different jetting an 88 model versus say post 91 models with 630 kits?

just interested to know...

A 1991 on XR6 runs different jetting to the earlier versions, no matter what state of tune the engines are in. The '91 on models came with a much smaller main jet standard (#152 versus #165 for '88-'90 models) to compensate for a narrower airbox boot that was fitted on these later models. The airbox boot was modified to allow the fitment of the wider (and much improved) shock on the '91 on versions.

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