HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
davo ttt

whats the jetting deal

21 posts in this topic

hi i just want to know why everyone keeps talking about changing this jet that jet why are all these changes needed i bought my wr in 06 and it runs perfect its only got 600kms on the clock for what reason do these bikes need jetting changes

Share this post


Link to post
Share on other sites

stock the bikes come jetted lean for emissions. Once you start uncorking the engine (exhaust, open inlet, throttle stop & other free mods etc) you need to keep the air fuel ratio correct to get the full potential from your engine.

If you haven't done the free mods I would suggest you try it.....unleash the beast:eek:

Share this post


Link to post
Share on other sites

on my first service they took the throttle stop out and something from the exhaust then the other day i took the smaller pipe tip out of the exhaust and disconnected the grey wire i think it is more snappy but it doesnt seem to have any running problems or should i take i to the shop i havent done the airbox mod will it make any diff or just let more dust in

Share this post


Link to post
Share on other sites

check your plug and it will be bright white, way too lean, when you let more air in (aka airbox mods) and more air out (tailpipe tip) you need more gas, and have to jet up. TRUST US or your engine will run lean, backfire on decel and eventually burn up the piston also.....

Share this post


Link to post
Share on other sites

I haven't jetted the carb yet,, I only have 3 hours on the bike,, but to any new owner of a WR ,, trust these guys in this room ,, they know there shit.

With that said ,, can you adjust the choke ,, it revs up to much

Share this post


Link to post
Share on other sites

It will rev too high when jettet lean also............But its suppose to rev up with the choke on for quick warm up

Share this post


Link to post
Share on other sites

I think you will find that after the initial break-in the bike will start acting up (ie popping, hard starting, and hesitation with a blip of the throttle)

Your gonna need to re-jet AND adjust your valves for a kick-ass ride.

I meet people all the time with these bikes and Hondas that say they aren't running right or hard to start.

Have they adjusted the jetting or valves? Nope....

AND NEVER take you bike to the shop.....for these things...just a hint to save you money:busted:

Share this post


Link to post
Share on other sites

I just got my 06 450 and want to take out the throttle stop. But I can't figure out how to get at the screw. The tutorial on the thumperfaqs is not the correct year, and I can't get at the screw, how do you do it, anyone have pics?

Do you need to rejet after the throttle stop mod?

Share this post


Link to post
Share on other sites

Pull the carb, then it's no problem. If you're not running a larger main, you may want to up it to at least a 168, check the database...SC

Share this post


Link to post
Share on other sites

Is it possible to pull the carb out enough to get at the throttle stop without dissconecting the throttel linkage?

Share this post


Link to post
Share on other sites
Is it possible to pull the carb out enough to get at the throttle stop without dissconecting the throttel linkage?

No, but it is only 2 allen screws and 2 minutes of patience.:worthy:

Share this post


Link to post
Share on other sites

i never removed my carb, just the cover and cables and got at the screw that way, an offset bit may help........ you will notice a HUGE diff once replaced with a YZ one, or cut down to YZ specs.

Share this post


Link to post
Share on other sites

Dunno if the 06 is like the 05 but all I had to do was unbolt the AIS unit from the frame and I had pretty easy access to it. (That was before I binned the AIS......)

Share this post


Link to post
Share on other sites

Ok maybe its a dumb question,, I'm going to order the JD kit this week ,, what jet does it come with,, do I need to tell them what sea level I'm at,, or what jets I would like,, also I see on the yamaha site they have a replacement cap the the exhuast ,, do you think that will do the trick

Share this post


Link to post
Share on other sites
Ok maybe its a dumb question,, I'm going to order the JD kit this week ,, what jet does it come with,, do I need to tell them what sea level I'm at,, or what jets I would like,, also I see on the yamaha site they have a replacement cap the the exhuast ,, do you think that will do the trick

JD kit comes with some main jets (160 -170 I think) and two tapered needles with multiple clip positions as well as some o-rings for the AP linkage.

The selection will sort most of your jetting selections.

Which cap are you referring to on the yamaha site?

Share this post


Link to post
Share on other sites
Dunno if the 06 is like the 05 but all I had to do was unbolt the AIS unit from the frame and I had pretty easy access to it. (That was before I binned the AIS......)

I tried unbolting the AIS and I still could not get good access to it. It is so tight, I can't even get my hand in there let alone turn an allen key to take it out. That throttle stop screw really pisses me off,:worthy:, why couldn't they just put the right damn screw in, in the first place?

Share this post


Link to post
Share on other sites

I actually accessed it from the opposite side of the bike.....really! I used a flexy stem on a little socket set I had with hex bit fitted. I cracked the bolt with a conventional allen/hex wrench then used the flexy setup to quickly remove it.

Share this post


Link to post
Share on other sites

By the way, dont cut off too much. The previous owner cut mine too short and when I removed the slider assembly to change the needle, the shaft spun past the throttle stop screw and bent the accelerator pump linkage. 20 mm below the screw head is whats recommended.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0