Leak Jet v/s Needle Position ?

Have a '05 WR450F with 2,500 Kms.

Running fine in all the powerband range (I think)

- 48 pj

- 175 mj

- 0 leak jet (no bog :banana: )

- Stock needle

- 1 1/4 fuel screw

- AIS mod, grey wire mod.

- Air box mod (snorkel out & side cuts)

- Stock muffler modded ("Dodjy Mod")

- plug color: tan

- 0 to 2,000 ft, 60 to 75 'F

Have the JD Needles (blue & red) but never have used them. :ride:

Now I am wondering if changing the stock needle could make a big diference.

Better power response ?, more crispy ?

If the answer is yes, on account that I am running "zero leak jet", how that influence the decision of using JD red or blue and the clip position ???? :ride::ride:

Thanks.

The leak jet has absolutely nothing to do with the needle.

OK Redbeard.

Will follow the Indy´s guide to decide wich JD needle to use.

Thanks.

No problem. The needle can sometimes effect the pilot, but the AP circuit and leak jet is a completely different circuit. Although when i was experimenting with the AP mod I leaned my needle until I was able to lessen the AP squirt with a larger leak jet but goofing around like that should be left to the jetting professionals. Don't try this at home kids! :ride:

Be sure to follow their main jet recommendations as well. The JD needles taper differently than the OEM, and because they are fatter at the bottom, a larger main is needed to compensate.

Be sure to follow their main jet recommendations as well. The JD needles taper differently than the OEM, and because they are fatter at the bottom, a larger main is needed to compensate.

Yepper! :ride:

OK., now I use a 175 main jet, could be enough,..... shall see.

May I expect a significative improvement, by replacing the stock needle for a JD blue or red ??? :ride::ride:

Thanks.

Hi

There has been a lot of past flack for the JD setup VS. OEM needle.

All I can say is the Clark4131 and Indy tables are real close for the JD needles and my bike runs great. Switched from OEM to JD with ALL mods on Day1!

I have found the WR (06) almost hyper sensitive to temp/humidity changes and largely agree with the said tables- every 5c you need to change for optimum running and we are only talking 3-5% change in fuel flow!

Looking at your Jet specs. I would try the JD red on #5 or 4 with a 170 Main, Fuel screw 1.5 out. I reckon you are probably too rich on the main and the bike may not be revving cleanly on WOT? The 48# pilot is Good even up to 90F when I have mine at around 1.25. I'm running a Power Now so I think it can take a richer off idle setting. Less than 1.0 and you want to switch to a 45. Otherwise it is a personal choice whether you switch, if your bike runs OK then dont "fix" it as the saying goes. if you are curious and like tampering - then go ahead.

As all jet have an influence on fuel flow at various stages of throttle opening it is best to set MJ first for WOT clean running and strong pull, then pilot circuit then needle then fine tune.

:ride:

OK., now I use a 175 main jet, could be enough,..... shall see.

May I expect a significative improvement, by replacing the stock needle for a JD blue or red ??? :ride::ride:

Thanks.

Try the JD red and you will need to lower your main jet and it will help with making your leak jet more effective! Scrap the stock needle or buy a stock WR 04 needle. The JD red in clip #4 from the top is a great choice for a slightly modded bike. Drop down to a 170 main

I'll try the 170 mj, although with the 175 mj at WOT it keeps reving and pulling forever. Also will try JD Red on 4th.

Also, maybe I'll go back from 48 pj to 45 pj, cause now we are in winter here and my FS is at 1.25.

Thank you guys (Indy & OneToGo) :thumbsup:

I'll try the 170 mj, although with the 175 mj at WOT it keeps reving and pulling forever. Also will try JD Red on 4th.

Also, maybe I'll go back from 48 pj to 45 pj, cause now we are in winter here and my FS is at 1.25.

Thank you guys (Indy & OneToGo) :thumbsup:

Just to make sure you got that right, easy to typo I know....as the temps drop you need a bigger pilot and fuel screw further out. If you put the 45 in then you will have to wind the fuel screw way out. I would advise leaving the 48 and try turning the fuel screw further out first... Pilot and main are easy to change so do the MJ first then test (with the 48 and 1.5 turns out). I reckon you'll find no need to go to the 45. :ride:

Hi OneTo Go:

Let me explain in a better way concern.

Cause we are already in winter here (60s F) and my bike is dialed ( :thumbsup: ) with 48pj and FS 1.25, what can I expect in summer (70s F). :cry:

I anticipate, it will be a must to go under 1.0 turn on the FS in summer, because 48 pj will be too rich.

Also, How do I know the need to change the main jet ??? :ride:

Right now with 175 mj I can´t feel any bog or sputtering at WOT.

Thanks again, I'm learning a lot. :ride:

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