Help with selecting needle

[Honda 250r 001]

Currently i am running a DGH needle. Not working out for me.
Motor is a
310 CT "national" porting
39 PWK 7 slide, 178 main jet.
ESR trx 5 centermount
Boyesen reeds
cr ignition
Esr airbox eliminator

When im out of the powerband, in the low end, JUST below the powerband and i punch the throttle, it sputters and bogs for 5 seconds before going into the powerband. I believe this may be a wrong needle? What needle should i buy to change it? Or any other suggestions?

[wes350x]

I believe you should try the CEL. It is a lil leaner

[Honda 250r 001]

Well after reading over the duncan racing jetting guide. I believe my taper should be changed? I need a little leaner in the 1/2 to 3/4? OR maybe richer? I was going to try a CGH which is one leaner on the taper because everywhere else my power seems pretty good, does anyone thin this would help my problem?

[rocketshops]

I would look elsewhere for your problem, I have a CT 330 with pretty much the same setup, and I have been all over the place with needles and always seem to go back to the DGH.

[hondamancbr03]

I have close to the same set up as you except i have a 350, i had a DGH that gave me problems right off throttle but got better after 1/4 throttle. I switched to the CEL and it runs great...Check out this website and decide what area you feel needs to be adjusted. No one knows more than you how your bike is reacting to the current jetting.

http://www.justkdx.dirtrider.net/printcarbtuning.html

[Honda 250r 001]

I can order the correct needles to fine tune wether more fuel or less fuel needs to get to my motor. But im not sure if it needs more fuel, or less? When it starts sputtering, Like say out of a corner at a race. And i pull the clutch, it misses a couple times when i still hold the throttle wide open, then it takes off and i dump the clutch again. Does this sound rich or lean? Or should i just order a richer and a leaner needle and try it?

[hondamancbr03]

Don't be fooled with a studder or sputter only being to rich....A lean condition can sound just like a rich condition. The old school way was to start with jetting that is known to be fat and work down until it's running great. I would put in a new plug and run the bike for up to 5mins or so in the throttle position that is causing the problem and then pull in the clutch, kill the bike without giving it the chance to idle, pull the plug and check the color.....Also known as a "Plug Chop".

To me it sounds like it's loading up when you back off the throttle as you enter the corner, then you have to clean it out as you exit. Like i mentioned, I run a CEL and 178 main in a 350 with a 38PWK and have over a full season on that jetting, your needle is richer than mine in all areas.

[buford]

I don't know your elevation but try a DEJ in the middle clip position. It's richer in the 1/4-3/4 throttle setting than the needle you currently have and is probably a bit of your problems. It's also leaner 1/8 to 1/4 throttle, the is the bobble you are experiencing. CEL is leaner all over and way lean on 1/8 to 1/4 throttle.

Most 250r's of the size of motor you have I have tinkered with in the past seem to like a 50-52 main, DEJ in the 3rd of 4th clip and a 172-178 main. This is at sea level with no air leaks anywhere and a clean air filter running race fuel.

[Honda 250r 001]

Another thing is, my problem is not when the motor is revving up, its when i have the slide all the way open, but the motor is still in the 1/4 - 1/2 range. So does this mean i need to look to change things in the 1/4 - 1/2 range (such as needle and slide cut away), or wide open range (main jet)? Im running 1,400 feet elevation.

[buford]

I would still try a DEJ in the middle clip and then run your bike at half throttle in 3-4th gear for a stretch, shut it off, cost to a stop then check the plug color. You can check your plug in the 1/4, 1/2,3/4 throttle openings just like you would do a full throttle run to check your main jet.

[hondamancbr03]

Originally posted by Honda 250r 001
Another thing is, my problem is not when the motor is revving up, its when i have the slide all the way open, but the motor is still in the 1/2 range. So does this mean i need to look to change things in the 1/2 range (such as taper and length), or wide open range (main jet)? Im running 1,400 feet elevation.

I thought you mentioned the problem was in the low end prior to power band? Does your bike have any port work and of so what type of porting?