Jetting "a la Taffy" - Satisfied Customer

Well boys, I do like to be different so when I saw Taffy going off in his own direction I grabbed his coat-tails. Call me a plagiarist. I dont care. It WORKS. Cust #1 is WELL satisfied. :)

Hop on board people and when you do, don't dick around....go the whole hog in one jump as this is a working interactive system which likely wont work in 'sections': I tried a different needle with similar jets and although it was workable, wasnt great all round. This setup IS.

99 WR400 YZ timed


38 PJ

55 PAJ

155 MJ (Taffy now moved to 150)

165 MAJ (Taffy now moved to 160)

EMM Clip 4

Fuel Screw 1.5 turns



First gear starts - Great

1'st-2'nd gear wheelies - just snap the throttle

3-4-5 'th - carefull, wheelspin city.

Uphill 3-4'th gear hauls - revs. like crazy

Mid range - RAPED APE!

Top Speed - don't know, my speedo is a little cranky, but FAST as hell

In a fall - will NOT stall

Decel - no popping but no sign of richness that I can tell.

Excellent fuel economy

Just Do It

PS : A small word of WR still has the stock EU exhaust as does Taffy's, although he has a FMF PB header. I'm sure JD and/or Taffy could provide some insight into adapting the above for a freer flowing exhaust.

Good for you Missle!

Now when gonna you fix your bike and do the "JK" mod to it? :)

Kevin, as you mention it I do need a winter project ! Do you think a 0.1387326 sec. long squirt sounds about right ??

Heh Missle,

I was hoping you could describe the difference at WOT max torque and max revs to me using the smaller MAJ. I've got my new (smaller) MAJ's but havent had a chance to try them out yet.

I'm assuming that before you made the "leap of faith" with Taffy that you were using the stock 200MAJ with some MJ (probably around 165-170). How is the top end different now...and what are the good signs to look for when comparing the two?



started out stock

168 MJ

200 MAJ

45 PJ??

85 PAJ

Needle DXM (I think) clip 3 or 4

I did WR to YZ timing as well as deoctopussing in about 4 hops to 165 MAJ 155MJ 38PJ 55PAJ EMM #4.

Now changed to 160MAJ and 150MJ.

I dont get much chance to open up and hold WOT.

The riding I do is mostly/all woods so holding WOT is not an option for more than a few seconds unless I'm roading.

All I can say is that it seems way better than the WR I had before all these changes.

It is consistent thru the revs, no hiccups anywhere, mid range is just literally on fire and feels so smooooth.

I spent 3 hours slamming in and out of gears 1,2,3 through logging ruts with iced water above the wheel line with nary a problem at low chugging revs or power mud pulls. When I maxed up the speed between sections in 3 4 5 it just piled on the power like no tomorrow.

I dont know if I'm helping you here but if you have anymore questions let me have em....

Thanks. I do the same type of it's not like I'll get that much experience with WOT either. I'd just like to get the main circuit figured out completely before goofing around with the pilot circuit...

Yeah...there's definitely a difference between my E series needle-jetted, WR timed bike and my amigo's D series needle-jetted, YZ timed bike. He kicks my arse in the mid range still...but not my much. Cant wait to change to YZ timing...and then I'll be top dog...assuming that "top dog" means going the fastest before hitting that large tree... :)


Speaking of large trees.....I got deviated the other day, you know..just tooling along and suddenly, WAP, I'm veering left towards the 45 degree slope littered with oak, spruce etc aaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhh... frantic right steering & leaning, front wheel is washing oooooouuuuuuutttttt...... PHEW ....caught it!

Guess what my christmas present(s) to myself will be :)

[ December 05, 2001: Message edited by: The Missile ]

[ December 05, 2001: Message edited by: The Missile ]


as a matter of fact ....yes.....I also had my first real WR mudbath last Saturday.... even the skin of my ass was black with the stuff....I didnt even attempt to wash my underwear. OK I promise I'll stop with the details now.... :)

:) THAT was much more detail than I needed to know ROFL :D:D

taffy, i have a question if you're reading this. i was wondering how much better do the WR/YZ's go after your jetting work. If they are that far out from the factory, imagine how much better they would do in the new bike tests you read about. i wonder how many people sell their WR's and move to a KTM just because they are dissapointed with the standard performance. wouldn't it be good to see a bike test with a standard WR (the one the magazine journalists would get anyway) and a WR fully 'taffy tuned'.

the jetting can only be so far out and you can only make it so much better.

i've just said the same thing on the KTM side. but it's when they start easier, start hot or cold easier. when they do double the MPG. when they chug away on the kickstand and you know it's right.

it's even got more top speed.

definately a rewarding experience and one that rewarded my 15/20 years involved in bikes and racing. right man in the right place at the right time.


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