DR.D pipe on 2008 yz450f


28 replies to this topic
  • mxdigger

Posted October 19, 2007 - 07:00 PM

#1

Help........ Just put on my new DR.D stainless full system. Per Dubach Racing, I changed the main jet to a 162 and dropped the clip to the 4th position. It is now backfiring a little bit on decelleration, and it is shooting out flames when I hold it at about quarter throttle in neutral. Air leak??? Is there supposed to be a clamp on the header and tail connection. It did not come with one, and the stock one does not work. Also, the header pipe was glowing so bright, you could have lit a cigar. Is this normal. Any suggestions? Running it at sea level.

  • MotoXT

Posted October 19, 2007 - 07:52 PM

#2

Help........ Just put on my new DR.D stainless full system. Per Dubach Racing, I changed the main jet to a 162 and dropped the clip to the 4th position. It is now backfiring a little bit on decelleration, and it is shooting out flames when I hold it at about quarter throttle in neutral. Air leak??? Is there supposed to be a clamp on the header and tail connection. It did not come with one, and the stock one does not work. Also, the header pipe was glowing so bright, you could have lit a cigar. Is this normal. Any suggestions? Running it at sea level.


Same exact thing happened to me last weekend. Spoke with Dr. D and they suggest going up on the pilot. I'll be trying it tomorrow. The bike is supposed to backfire some, but as in your case mine was excessive. You can try going out on your fuel screw, but if you get too far beyond 2 1/2 turns go up on the pilot. There are a ton of threads on here with great info on proper jet set-up, so check them as well.

  • grayracer513

Posted October 19, 2007 - 08:06 PM

#3

... it is shooting out flames when I hold it at about quarter throttle in neutral.

The pilot jet is too lean

Is there supposed to be a clamp on the header and tail connection.

No clamp.

The glowing header is semi normal, but is being exaggerated by the lean pilot?

  • Chilio

Posted October 20, 2007 - 05:27 AM

#4

I had one of the first 08s in SoCal with the Dr.D pipe and I follow their instructions, 162 main and 4th clip position. Had a lot of backfiring on decel. I ended up going back to stock on the main and clip but I change the pilot to a 48, air/fuel screw is about 1 3/4-2 turns out.

Hope this helps.

  • matts06yzf

Posted October 20, 2007 - 03:23 PM

#5

I changed mine also but changed back to stock I like it better at stock and of course keep my fuel screw Adjusted:ride:

  • Chilio

Posted October 27, 2007 - 06:42 PM

#6

Alright guys, I haven't been very happy with the jetting on my bike with the DR.D. I met with Dean with R & D power bowl and he got my bike running great. I did get a power bowl and man that makes the bike so crisp.

Here are the specs

R & D Power Bowl
main jet 165
pilot jet 52
air/fuel screw 2 turns out

  • todds924

Posted October 27, 2007 - 07:46 PM

#7

Alright guys, I haven't been very happy with the jetting on my bike with the DR.D. I met with Dean with R & D power bowl and he got my bike running great. I did get a power bowl and man that makes the bike so crisp.

Here are the specs

R & D Power Bowl
main jet 165
pilot jet 52
air/fuel screw 2 turns out


52 pilot????????????? Wow. thats pretty big. How does the bike start when you stall it when its good and hot?? Where are you running the leak jet screw at on the power bowl?

  • Chilio

Posted October 28, 2007 - 05:25 AM

#8

52 pilot????????????? Wow. thats pretty big. How does the bike start when you stall it when its good and hot?? Where are you running the leak jet screw at on the power bowl?




I couldn't believe I need a 52 either, but it works. I'm not sure about the leak jet screw, Dean set that up.

The bike starts so much easier, so much in fact my buddies in the pits noticed it.

  • todds924

Posted October 28, 2007 - 05:58 PM

#9

I couldn't believe I need a 52 either, but it works. I'm not sure about the leak jet screw, Dean set that up.

The bike starts so much easier, so much in fact my buddies in the pits noticed it.


Wow thats amazing. Are you going to be at I-5 Gorman in two weeks? I'll make sure to check you out then!!!! Went and practiced at Perris today. Dubach was there tearing it up. Sure didn't look like his 08 was hurting for power!!!

  • Chilio

Posted October 29, 2007 - 03:20 PM

#10

I might go to Gorman but that is a really long drive for me.

I also heard about Dubach @ Perris, that guy still rips.

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  • todds924

Posted October 29, 2007 - 03:40 PM

#11

I might go to Gorman but that is a really long drive for me.

I also heard about Dubach @ Perris, that guy still rips.


Hell yes he does. Vet x is at Racetown this weekend. Then Perris the next then I-5 Gorman. Races for the next 3 straight weeks.

  • kx1984

Posted October 29, 2007 - 09:19 PM

#12

I couldn't believe I need a 52 either, but it works. I'm not sure about the leak jet screw, Dean set that up.

The bike starts so much easier, so much in fact my buddies in the pits noticed it.


I'm up to a 48 with the DR. D on an 08 and it sure seems like it needs a 50 or better. I'm confused because the mags saisd it was killer with the stock jetting. Even before I put the pipe on it it seemed like it needed a larger pilot.

  • Ga450owner

Posted October 30, 2007 - 06:14 AM

#13

I'm up to a 48 with the DR. D on an 08 and it sure seems like it needs a 50 or better. I'm confused because the mags saisd it was killer with the stock jetting. Even before I put the pipe on it it seemed like it needed a larger pilot.


agreed they all need a larger pj.....

  • Chilio

Posted October 30, 2007 - 06:18 AM

#14

I'm up to a 48 with the DR. D on an 08 and it sure seems like it needs a 50 or better. I'm confused because the mags saisd it was killer with the stock jetting. Even before I put the pipe on it it seemed like it needed a larger pilot.



I'm not sure it the powerbowl has anything to do with the 52 pilot jet but it works.

First, he thought is was rich and tried a 42, much worse.
Second, tried a 48 and was better but not great.
Third, was the 52, what a difference!

The bike rips now with the 52, and powerbowl.

  • 917 rider

Posted October 30, 2007 - 02:51 PM

#15

i put mine on my 08 450 with no problem runs perfect with stock jetting

  • matts06yzf

Posted October 30, 2007 - 05:07 PM

#16

i put mine on my 08 450 with no problem runs perfect with stock jetting


MIne too. I pulled 2 holeshots this weekend on it.

  • todds924

Posted October 30, 2007 - 05:34 PM

#17

The largest pilot jet I have seen on any of the 450's 06- 08, is a 50. That was an 06 with a pro circuit pipe. I dont know if the powerbowl has anything to do with it- I dont see how it could. If it runs great i guess thats all that matters right. The only thing i'm very curious about is how your bike starts when its good and hot, like if you stall it during a race. I know when i used a 48 my 06 wouldn't start very well when hot.

  • 917 rider

Posted October 31, 2007 - 02:52 AM

#18

The largest pilot jet I have seen on any of the 450's 06- 08, is a 50. That was an 06 with a pro circuit pipe. I dont know if the powerbowl has anything to do with it- I dont see how it could. If it runs great i guess thats all that matters right. The only thing i'm very curious about is how your bike starts when its good and hot, like if you stall it during a race. I know when i used a 48 my 06 wouldn't start very well when hot.


first or second kick everytime hot or cold:thumbsup: :worthy:

  • todds924

Posted October 31, 2007 - 03:57 PM

#19

first or second kick everytime hot or cold:thumbsup: :worthy:


917, your talking about your bike with a DR D and stock jetting? My 08 is almost perfect with the stock jetting. Pro circuit Ti-4 pipe. I only bumped the main 1 size and put the fuel screw at 2 1/4

  • Chilio

Posted October 31, 2007 - 04:19 PM

#20

917, your talking about your bike with a DR D and stock jetting? My 08 is almost perfect with the stock jetting. Pro circuit Ti-4 pipe. I only bumped the main 1 size and put the fuel screw at 2 1/4



Todds, your welcome to try my bike at the next Vet-X race, with the powerbowl its like a different bike!





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