jet needle

[rboyer]

I have a 38mm pj carb and the needle has no letters or markings on it all..I think it is my jetting problem and the cause of my rich bog and bad throttle response...I have a stock jug, lrd pipe, some porting(from what I can see),k+n filter w no lid, and vforce reeds....does anyone know what needle they used in a 38mm w a similar set up, so I have a somewere to start with needle selection..

[Langbolt]

try a DGH

It's a good all around needle....should clean up the bog too!

:devil:

[rboyer]

Thanks I will def try it...and get back w results in a couple days.....thanks again

[rboyer]

I tried to get it at the honda dealer and they said they couldn't find it? I told them dgh....is that a aftermarket needle?

[rboyer]

I found it on the net....I wonder why the honda dealer didn't know what I was talkin about? There usually really good

[rustyATV]

Originally posted by rboyer
I found it on the net....I wonder why the honda dealer didn't know what I was talkin about? There usually really good

Most dealers only stock mains because nobody understands what everything else does. I've had numerous people try argue that the needle doesn't change anything. But then I show them this image.....

http://img.photobucket.com/albums/v11/hoppy/calchart.gif

[rboyer]

Thanks that makes a lot of sense....I changed the pilot and main and it didn't help the problem at all....just effected other areas that were fine to begin with.....if I snap the throtle it has a rich bogg...I moved the clip one way and it got worse...moved it the other way and got a lean bog....I don't see any letters or numbers on the needle that is in it I looked so I don't really know were to start with it...I'm goin to try the dgh needle like langbolt suggested...u have any suggestions?

[rustyATV]

I have a similar issue with my YZ250; off idle is tough to dial in. I haven't messed with it lately, but I'm thinking (just a theory) that the straight diameter needs to be a little on the rich side for it to run cleanly when you snap it open.

No really good suggestions other than to check the plug after running the engine in the different ranges below, and make your needle and jet selections based on that. It can be a little monotonous because you have to order needles every time you want to make a change.

My preferred needle is a CEJ, but that isn't a whole lot different than a DGH.

Here's the other image you need to figure out what needles do:

http://img.photobucket.com/albums/v11/hoppy/pj_34_39_jn-1.gif

[C-LEIGH RACING]

Cylinder porting, pipe & reed cage plays a big part in that bog.
If you have high porting & reeds to match then the pilot & needle got to be spot on for it to respond from the snapped throttle.
Neil

[Langbolt]

Rboyer:

Give us a breakdown of your current carb settings:

Main Jet :

Pilot Jet:

Throttle valve Cutaway: (the number underneath it)

Air Screw Setting: (How many turns OUT from gently seated postion)

Then we can better assist you.

:devil:

[rboyer]

Let's see..when I got it..it had a crankseal leak..it had a 152 main, 48 pilot, and 1/2 turn out on the air screw..with a br7 plug..not sure of cutaway or needle.....so I put in a br8 in fear of meltdown, and fixed the crankseal...I was in the middle of jetting it and bent the choke/idle and tried to straightin it and it broke..I will be pickin that up friday when I get $...currently there is a 160 main, and 40 pilot(which I think may be to lean) but I tried to move the clip down and the rich bogg got worse...moved it up and it then got a lean bogg....

[rboyer]

I think I need to be near 155main and 45 or 42 pilot....but nothing I did really fixed it....I have to clutch it to get it to snap into powerband...like I said the broken idle/choke knob killed my jetting session...

[Langbolt]

Does It Idle ???

I'd say you need a 52 or 55 pilot.....with the air screw only 1/2 turn out.

If the Air screw was 3 turns out you'd need to go leaner on the pilot

You wanna try and get the air screw set to 2 turns out.....then you can adjust in or out depending on the weather without changing jets.

Try the 55 pilot and set the Air screw to that you get the highest idle (Use a Tachometer if you can get one)

Count the number of turns out......if your at 2 complete turns you're good.

The BOG should be non existant when snapping the throttle

If there's a bog when riding between 1/8 & 1/4 throttle change the needle to a DGK

Test the Main jet with a plug chop......get it so it's milk chocolate brown

The BR8ES plug should be fine!

Now RIDE & RIDE & RIDE

:devil:

[rboyer]

A dgh or a dgk needle??

[rboyer]

I can't believe I was goin the wring way with the pilot....good call langbolt....I feel pretty dumb...thanks for catchin that..this is my first time jetting a carb....ill deff try a 52...and I'm rebuildin the top end jus for giggles, and doin a leak down test again...just to be tripple sure...

[Langbolt]

No problem.....that's why we're ALL here....to help each other out!

I suggested the DGH needle as a starting point.....if the 1/8-1/4 throttle is still a bit rich then switch to the DGK.

It makes the off idle responce crisper (leaner)

DEFINITELY do a leak down.....nothing worse than a seizure due to a leaking intake gasket.

And make sure your Air filter is clean & well oiled.

Always do jetting uder Ideal conditions.....then when the filter gets dirty it'll get richer not leaner.

If you Jet with a Dirty filter.....when you clean it then you'll run lean!

:devil:

[rboyer]

Just got my idle knob and a 52 pilot...how many turns out on the idle knob? It just says 1500 rpm in the manual... And u screw it in the raise the idl and screw it out to lower it? Is tha corret?

[Langbolt]

It's trial and error.....In to lower idle.....out to increase.

If you pull it UP...choke is on....Down...choke is off.

Do you remember your old setting ??

This is like on the Stock carb Right ???

If not..... it's just the Idle screw that raises the throttle slide....then in is to raise the idle....and out to lower it.

Do you have a TACH ? or know what 1500rpm sounds like ?

:devil:

[rboyer]

Its a pj38....I'm guessin a stock cr250 carb..the idle/choke knob...the honda shop called it a starter valve....and no I don't have a tach or know exactly what 1500 rpm sounds like