Fighting Jeting problem

[Jim Dettman]

<< I can bottom out the fuel scew all the way and the bike still idles fine>>

Sounds like it's too big to me.

Jim.

[CRF DOC]

48 pilot is fine.

You have a worn needle jet (emulsion tube) that is allowing fuel to pull past the needle at idle, bypassing the pilot jet.

[Maverick26]

48 pilot is fine.

You have a worn needle jet (emulsion tube) that is allowing fuel to pull past the needle at idle, bypassing the pilot jet.

So my red JD needle is worn? or the tube it rides in? good lord when does this end? Ok, so since JD does not sell replacements what are my options?

[CRF DOC]

The emulsion tube ( called a needle jet) is worn...replace with OEM.

[Maverick26]

Ok cheap and easy enough, this is what the main jet screws into and the needle itself slides up and down. I could see it wearing out with fuel eroding it and the needle sliding up and down it. Ill get and new one and see if it works.

[FORMA MOTO]

Start with one turn out

Drop idle with idle screw as low as it will go

Now try and raise idle with fuel screw

[Maverick26]

Ok I tried again last night, took the bike out and drove it around for 10-15 min to get it all nice and warm, adjusted fuel screw, new R&D flex, to 1 turn out. Then started tuning down idle from around 1700 down to about 1300 or so.. It died once so I know it was about as low as I could get it. Then I started to scew in the fuel scew and bottomed it out... nothing, still idling at around 1350 so I tried to screw it out and got all the way to 2 turns out... with no change in idle speed at all. I put it back to 1.25 turns out for now. It seems to run good there with no decel pop and no stumble. Im just wondering if this is good enough or is there something better? Should I try and replace the needle holder to see if it is worn like what Doc says? Its only like an $8 part so it might be worth a shot.

[FORMA MOTO]

Ok I tried again last night, took the bike out and drove it around for 10-15 min to get it all nice and warm, adjusted fuel screw, new R&D flex, to 1 turn out. Then started tuning down idle from around 1700 down to about 1300 or so.. It died once so I know it was about as low as I could get it. Then I started to scew in the fuel scew and bottomed it out... nothing, still idling at around 1350 so I tried to screw it out and got all the way to 2 turns out... with no change in idle speed at all. I put it back to 1.25 turns out for now. It seems to run good there with no decel pop and no stumble. Im just wondering if this is good enough or is there something better? Should I try and replace the needle holder to see if it is worn like what Doc says? Its only like an $8 part so it might be worth a shot.

Doc knows.

I've had to replace my emulsion tube (needle jet) once at 300 hours, for similar symptoms.

[Maverick26]

Doc knows.

I've had to replace my emulsion tube (needle jet) once at 300 hours, for similar symptoms.

Im guessing my bike has over 400 hours, around 7000 miles (just from mantainance history) so it may be time. Ill pick one up tomorrow and try it.