DR.D pipe on 2008 yz450f

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

yes my bike still has stock jetting,i was expecting to have to change it after all the reviews but i cranked it up and it runs perfect,crisp throttle,next to zero backfiring so i dont see the need. it also has way more power:banana: :worthy:

yes my bike still has stock jetting,i was expecting to have to change it after all the reviews but i cranked it up and it runs perfect,crisp throttle,next to zero backfiring so i dont see the need. it also has way more power:banana: :worthy:

Sweeeeeeeet! I like the way my 08 runs with stock jetting also. I only went up one on the main. Fuel screw at 2 1/4. On my 06 with a Dr.D, I only went up one on the pilot.

On my 06 with a Dr.D, I only went up one on the pilot.
That's true of both of my '06's, too. I put them at 45/165 before I ever rode them, then when they got their Dr.D's, I changed nothing.
That's true of both of my '06's, too. I put them at 45/165 before I ever rode them, then when they got their Dr.D's, I changed nothing.

Hey Gray, I like the way my 06 runs with that set up but i've also tried an 06 with an NFLR needle that worked really well also. I believe thats the stock needle in the 07 and 08.

The NFLR is the stock needle on '07-8's. The difference between that and the NFLP that the '06 came with is that the R needle is one half step leaner in any position than the P. I don't know that it would be that significant, but people say they like it.

Personally, as soon as my '03 sells, I'll try the Zip-Ty mod, and see how that goes.

The NFLR is the stock needle on '07-8's. The difference between that and the NFLP that the '06 came with is that the R needle is one half step leaner in any position than the P. I don't know that it would be that significant, but people say they like it.

Personally, as soon as my '03 sells, I'll try the Zip-Ty mod, and see how that goes.

I'm pretty happy with the jetting on my 08 as it is right now. I have heard nothing but good things about the Zip -ty mod and was also thinking of trying it out. What exactly are they doing to the carb?

The core of the mod is a modification to the main circuit in which the main air jet is removed, the passageway drilled out and tapped for a larger MAJ, and then a different emulsion tube is installed.

They also do the accel pump "wiring" mod.

There are add-ons like the Power Bowl, and Zip-Ty's accel pump linkage, hot start nut, etc.

The kit apparently originates from an outfit named Factory Pro.

http://www.factorypro.com/Prod_Pages/prodcy45.html

Scroll down the page until you see "Tech Tips" about a third down. Lots of details.

The results are, going by feedback only, and not FP's claims, generally crisper, more responsive carburetion across the board.

The core of the mod is a modification to the main circuit in which the main air jet is removed, the passageway drilled out and tapped for a larger MAJ, and then a different emulsion tube is installed.

They also do the accel pump "wiring" mod.

There are add-ons like the Power Bowl, and Zip-Ty's accel pump linkage, hot start nut, etc.

The kit apparently originates from an outfit named Factory Pro.

http://www.factorypro.com/Prod_Pages/prodcy45.html

Scroll down the page until you see "Tech Tips" about a third down. Lots of details.

The results are, going by feedback only, and not FP's claims, generally crisper, more responsive carburetion across the board.

Thank you for the info, its exactly what i wanted to know.:worthy:

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.

What elevation are you at?

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