'02 XR4-Pulled snorkel only, per Kevin FAQ rejet with 55/155, bike had in it a 60/160

Picked this bike up a few months back. Per Kevins Mods I decided to remove snorkel then rejet. After removing snorkel and pulling the carb bowl off, I discovered I already had a 60 / 160. Per Kevin's mods, if I'm just pulling the snorkel I should rejet (make richer) with a 55/155. What is stock in these '02 XR400, possibly the previous owner could have changed? Bike runs great, just curious if it's possible these bikes came standard with a 60 /160?

well this not what the bike came with. they came with 142/52 which is what came in my 01 xr400. i think that the 160/60 would be a bit rich for the stock exhaust i think that the 155/55 would be good. i have an aftermarket pipe and 160/58 and it runs great. starts first kick. the extra has profound difference on starting. o by the way, going from a 160 main jet to a 155 would be making it leaner not richer

well this not what the bike came with. they came with 142/52 which is what came in my 01 xr400. i think that the 160/60 would be a bit rich for the stock exhaust i think that the 155/55 would be good. i have an aftermarket pipe and 160/58 and it runs great. starts first kick. the extra has profound difference on starting. o by the way, going from a 160 main jet to a 155 would be making it leaner not richer

I realize going from 155 to 160 is richer, what I was trying to say is that Kevin was suggesting in his FAQ section that once the snorkel is pulled, the next step would be to change out jets to a 55/155 (make richer than standard), however when I opened my carb I was surprised to find a 60/160, as I thought I would find something like your stock jets, that is something much leaner than 60/160 that were in there.... BTW, since snorkel removal, the bike starts 1st or 2nd kick.....may have been too rich all along?

Personally, I'd say that if she runs great I would just leave the jets in it that are currently there. If you are determined, pull the plug and check the colour of it after doing a quick burn around on it.

Black = Rich

White = Lean

Brown = Good

XR400 jetting by the owners is all over the ball park. Your bike had 2 jet sizes richer. It might run better that way or it might be too rich. Every bike is slightly different too. The 55 / 155 jetting comes from MX Action magazine and another source that I forget at this time.

I had the owner of a performance motorcycle shop offer to jet my bike and run it on a dyno as he was just sick and tired of XR400 owners asking for advice. I can't remember why I didn't take him up on it. :censored:

XR400 jetting by the owners is all over the ball park. Your bike had 2 jet sizes richer. It might run better that way or it might be too rich. Every bike is slightly different too. The 55 / 155 jetting comes from MX Action magazine and another source that I forget at this time.

I had the owner of a performance motorcycle shop offer to jet my bike and run it on a dyno as he was just sick and tired of XR400 owners asking for advice. I can't remember why I didn't take him up on it. :censored:

Funny, it's bone stock other than the snorkel removal, and the plug appears more grayish than brownish with the 60 /160......would have thought it would be a more brown to blackish in color? Will this coloration do harm to the bike?

BTW, thanks for all of your excellent tips and advise.....can't seem to get off this forum!

You could try richening it up with the fuel/pilot screw to get her just perfect.

Thats what I hate about jetting. Everything I assume about it, ends up not being right, or is still wrong. But thats only on my own bike, what I say on this forum seems to do pretty good.

In that case... count how many turns until the fuel screw seats just for a reference to where you were in case someone calls and distracts you.

o i see. yeah if it runs good then leave it alone. both my dad and i have xr400 had the same jetting same everything, except mine ran like the carb had 3 or 4 sizes bigger main jet. i have since rejetted for exhaust mods but it was a big difference.

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