boyesen ap cover w/40lj


54 replies to this topic
  • ncmountainman

Posted March 25, 2005 - 04:30 PM

#1

just got done installing it with the 40 leak jet,yee frikken haw!!! the bog is totally gone,the off idle response is just short of amazing. even starts better when hot. see my long version in the yz 450 forum under 'boyesen AP cover' :) :p :)

  • cruise

Posted March 25, 2005 - 04:50 PM

#2

good stuff :)

  • clark4131

Posted March 25, 2005 - 04:50 PM

#3

Glad I got one too...It should be here next week :) ...SC

  • Jackazz

Posted March 26, 2005 - 08:44 AM

#4

just got done installing it with the 40 leak jet,yee frikken haw!!! the bog is totally gone,the off idle response is just short of amazing. even starts better when hot. see my long version in the yz 450 forum under 'boyesen AP cover' :) :) :p


Dammit Man, now I'm donna have to spend another $90! :D

Seriously though, thanks for taking the chance on this product & giving us your results. :D

  • Dan_Lorenze

Posted March 26, 2005 - 10:08 AM

#5

Dammit Man, now I'm donna have to spend another $90! :)

Seriously though, thanks for taking the chance on this product & giving us your results. :)


Ditto.... Thanks....

NC, how bad was the bog that you had? My bike seems to be perfect, I don't see any bog anywhere, Does the Boyesen and the 40lj make the bike more "snappy"? I remember JD saying that the cover acts as if you had a 40lj, never though of using them in tandem.

Dan

  • ncmountainman

Posted March 26, 2005 - 11:01 AM

#6

Ditto.... Thanks....

NC, how bad was the bog that you had? My bike seems to be perfect, I don't see any bog anywhere, Does the Boyesen and the 40lj make the bike more "snappy"? I remember JD saying that the cover acts as if you had a 40lj, never though of using them in tandem.

Dan

i barely had any bog after the 40lj install,but it still reared its ugly head on occasion. my biggest problem was in tight nasty stuff where working the throttle is key to even making it through, if i worked it on/off quickly it would just die sometimes,just quit!! well someone mentioned in that yz thread that it may be running out of fuel in the pressure bowl due to a low fill level hole and refill time. well that was it because those issues are gone! :) its a whole new bottom end not a real snappy one like before that came in late and hit hard,but a mellow one that extends much lower and comes in instantly. makes the tight stuff ALOT easier. i can't say enough about how much difference there is. i guess the key is to use the #40lj with it. i'm gonna call boyesen to tell them about that tab i had to file off and also reccomend they include a 40lj in the future for the 03-05 models. they should send sumthin' free for this kinda R&D :)

  • clark4131

Posted March 26, 2005 - 12:42 PM

#7

i'm gonna call boyesen to tell them about that tab i had to file off and also reccomend they include a 40lj in the future for the 03-05 models. they should send sumthin' free for this kinda R&D :)


What tab?...SC

  • ncmountainman

Posted March 26, 2005 - 01:02 PM

#8

there was a tab like appendage on it that hit the float bowl before the holes lined up to screw it in. i filed it off and it worked fine. i looked at the picture of boyesen cover in the destructions and the tab was not there,so it was probably a casting tab that didn't get ground off properly

  • cnorton

Posted March 26, 2005 - 04:48 PM

#9

Transworld tested this cover on an RMZ 450 and said that it hit so hard off the bottom they had to take it off, can't believe a little cover can make such a difference!!

  • ncmountainman

Posted March 26, 2005 - 08:25 PM

#10

Transworld tested this cover on an RMZ 450 and said that it hit so hard off the bottom they had to take it off, can't believe a little cover can make such a difference!!

they need to put their panties on, it just makes it run like it should :)

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  • Tab812

Posted March 27, 2005 - 03:10 AM

#11

Man,That sounds real good to hear. I'll be buying one soon. :) :) :p

  • Dan_Lorenze

Posted March 27, 2005 - 09:30 AM

#12

Thanks NC......... :)

  • Unibomber

Posted March 27, 2005 - 02:42 PM

#13

I posted on the yz side, I just ran a hare scramble with my new ap cover and it was remarkable to say the least, I suck in the steep rocks, and this thing helped big time, only died once up hill. I even stalled up hill once and the bike stopped running for an entire second and then bump started up hill !!!!!!!!! :naughty:

  • NewBlue

Posted March 27, 2005 - 04:56 PM

#14

Ok, now I know that I don't have the credibility of NC; but, damn man I told you guys that the thing worked like three weeks ago. I had to drill out the holes to get the screws in them, but that is all that I had to do. I am not aware of where the leak jet is or what size my 02 has in it, but mine runs wonderfully. I added a Yoshi Comp slip on and the Boyesen ACc/Pump cover and that is about it. Well the free mods also have been done.

  • ncmountainman

Posted March 27, 2005 - 05:45 PM

#15

JD found the cover by itself is the same as lowering the leak jet size. i tried it with the 40lj and found all kinds of new bottom end. sorry i stole your thunder :naughty: so now we know it works as a smaller leak jet, and when combined w/the 40lj on the 03 and up its a must have as far as i'm concerned. compiled data :naughty: what i would like to know is if its the same thing as the p-38 (which is cheaper i hear) anyone have access to both to do a side by side. the only physical difference i could see(from stock)was that the fill hole was alot higher and maybe slightly larger. the reason you had to drill the holes was probably because that tab was hitting the float bowl(i had to file it off). when you put in one screw the others wouldn't line up right? or were the holes too small for the screws? i'm calling them tomorrow and let them know i wasn't too happy about having to custom fit the thing!

  • NewBlue

Posted March 28, 2005 - 09:38 AM

#16

The screws wouldn't line up properly, and I had a hard time getting them in the holes. I thought that maybe the holes weren't exactly drilled, or that the powder coating was in them. I didn't remove my carb to install the ap cover, it just loosened the screws that connected the carb to the air box and the engine and rotated it. I rode for the majority of last Friday, and I had two situations where it stalled. I am most impressed with this bike now. I may try the two cool stuff soon. I have used semi-synthetic to break it in , and full synthetic since the first oil change. The oil looked kind of funny to me, so I suspected some blow by. This last oil changed looked real good. As hot as these bikes get, it seems that using dino oil would be marginally irresponsible. Frequent synthetic oil changed seem like cheap insurance to me.

  • ncmountainman

Posted March 28, 2005 - 12:30 PM

#17

i just got off the phone with boyesen and they were aware of the extra metal and have addressed the problem since. so if someone gets one that doesn't fit just file off that tab that hits the float bowl. i also reccomended that they offer the 40 lj with the 03 & up they had not tested it as such and were gonna try it. i shoulda asked'em for a hat :naughty:

  • WRookie

Posted March 28, 2005 - 03:44 PM

#18

only 03 and up have leak jets.



My 02 disagrees. In the parts fiche they are labeled, jet, AP.

  • ncmountainman

Posted March 28, 2005 - 05:50 PM

#19

well i was goin' off what several people with 426's said,maybe its 02 and up? i really don't know,but i know i've got one :naughty: so anyone with a leak jet thats using the boyesen cover needs to try it with a #40lj. that should cover any discrepencies :D i fixed that previous post to generalize whatever years it applies to :naughty:

  • Seabass

Posted March 28, 2005 - 07:28 PM

#20

How do you install the leak jet? I understand it's in the float bowl but my manual doesn't mention anything about it. My local yamaha dealer doesn't know what it is!!!! :naughty: They talked me into the P-38 accelerator pump cover and now that I have it installed I'd like to try the 40 lj




 
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