BK Applications.....why the confusion?



4 replies to this topic
  • BlueThunder

Posted October 11, 2001 - 09:30 PM

#1

Is a 2000 WR400FM a candidate for the BK mod ? The masters of the jetting universe(ie James Dean & Taffy) both say yes but Garrett
(aka Motoman393) insists it does not? After removing my carb for the 100th time since I've owned the blue machine, I see no reason why it would not? The tab for the mod exists in the carb bodies casting and the AP's moving parts all coincide with the function of the BK so someone who has actually done the mod on a Y2K WR400 please indulge me....yay or nay ? Sorry for beating a dead horse but I'd hate to drill and tap a useless hole in the carbs body when I could spend that time tearing the headset apart to regrease it once again. Thanks in advance for all the TTer's input.

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Y2K WR400FM,Answer top tree w/Accu-Trax clamp,Pro-Tapers(CR-Hi w/ EE handguards),Devol Rad. & frame guards, Guts tall soft foam w/ ballistic cover, 14/52 w/DID VM X-Ring, Kouba-T,Michelin M-12's ft.& rr.,12 oz. flywheel weight, Zip-Ty Racing Link & Shark Fin(plus everythhing else cool that Ty offers), Cycra front rotor guard and T.M. Designworks Chain guide, buffer & chain wheels. Street legal except for the non-"DOT" tires.

  • BlueThunder

Posted October 11, 2001 - 09:33 PM

#2

This is the QUOTE from Motoman393...."If you recall Yamaha changed the YZ400 to a YZ426cc for the year 2000 models but the wr400 stayed a 400cc for year 2000! (thus the 00' WR 400 is esentially a 99' YZ400) The 400cc models (YZ and WR) have the 1st generation Keihin FCR 39mm "slant carb"..... the 426cc models (YZ and WR) have the 2nd generation Keihin FCR 39mm "straight" (non slant) carb! The listing on my site is very accurate, I know it is confusing (it was for me at first too). But basically if you have a 426cc WR or YZ the BK carb mod will work. If you have a 400cc WR or YZ the BK mod WILL NOT work due to the fact that it is an "older" carb that doesnt have a mount extruding off the side of the main body to drill and tap a screw/spring combo! This may sound confusing so if you have any further questions feel free to email me back! Hope this helps,"

Garrett (AKA motoman393 on TT)



[This message has been edited by BlueThunder (edited October 12, 2001).]

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  • Taffy

Posted October 11, 2001 - 10:00 PM

#3

who needs an APJ anyway!

Taffy

  • mcarp

Posted October 12, 2001 - 05:51 AM

#4

Blue Thunder-

i don't know where you get your info. But it's wrong. The 2000 WR400 FM INDEED has the revised FCR2 carb. The only difference is the jets/needles used and the YZ does not have an air cut valve like the WR has. The flange is definitely there to perform the mod. All 98-99's WR and YZ's don't have this
flange. All 2000 and up WR and YZ's do!!
I wonder if that person with the 2000 that gave you this info got a '99 carb switched on them?

James D confirmed this for me and some others months ago the mod will work. I have since performed the mod on my FCR2 on my 2000 WR400 with great success.

Go for it! I ended up raising the needle from 4 to 5, lowering the main jet two sizes, and readjusting my pilot screw slightly. There was about 1.75--2 seconds squirt stock and reduced it to the recommended .3 second (as best as I could "guess"). I deviated from the exact mod by setting the timing screw clockwise 1/3 turn from described. Your mileage may vary of course! I have yet to experiment beyond 3 sets of needles/main, thinking of trying one of the F series needles and maybe some of Taffy's wild experiments.

  • BlueThunder

Posted October 12, 2001 - 06:05 AM

#5

mcarp....read my post, it was quite clear where I got my info. Second post was a quote from Motoman393 to me when I e-mailed him. Check out http://mx393.tripod.com/carb.html
to see what I'm confused about. Great pics and instructions but misinformed about applications and applicable years to do the BK mod. I just finished doing mine this morning on my 2000 WR400. Now to see if it was worth the trouble...sure it was.For anyone else that wants to confirm usable applications for the BK mod all 2000 WR's can be done !

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Y2K WR400FM,Answer top tree w/Accu-Trax clamp,Pro-Tapers(CR-Hi w/ EE handguards),Devol Rad. & frame guards, Guts tall soft foam w/ ballistic cover, 14/52 w/DID VM X-Ring, Kouba-T,Michelin M-12's ft.& rr.,12 oz. flywheel weight, Zip-Ty Racing Link & Shark Fin(plus everythhing else cool that Ty offers), Cycra front rotor guard and T.M. Designworks Chain guide, buffer & chain wheels. Street legal except for the non-"DOT" tires.

[This message has been edited by BlueThunder (edited October 12, 2001).]




 
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