RB Designs and FRP

[Tedh98]

But is what i have listed a good place to start? a 42PJ and a 150MJ? with the CEL in the 2nd notch?

Could be, but there is only one way to find out. I don't have a KDX frame, so I'm not sure of this, but you should be able to make needle changes without pulling the carb. You may also be able to make MJ changes with just rotating the carb to get to the bottom of it.

I will say that the 150MJ seems lean for your WV elevation. I ride between 700-1000 feet in Georgia and I run a 155. That is a little on the rich side, but I would rather error in that direction than be too lean. No way I could get away with a 150. But again, different engines . . .

[Slick_Nick]

I have the RB head and carb and a ported cylinder with VForce 3 reeds. I run a 38 pilot and 140 main.

[Tedh98]

I have the RB head and carb and a ported cylinder with VForce 3 reeds. I run a 38 pilot and 140 main.

OP has a 200

[KDX_Johnny]

Maybe ill start at a 152. A happy compromise since you say you're a hair on the rich side. I may try an 1173 needle too. But how about my pilot? does 42 sound reasonble?

[Tedh98]

42 does seem reasonable. What pilot do you have now?

[KDX_Johnny]

Stock, so i guess 160 main and 48 pilot?

[KDX_Johnny]

ill know for sure when i rip the carb out later

[KDX_Johnny]

i may have to turn my idle way down low too to compensate for the lack of fuel. Also do you think an 1173 needle sounds good? 1174 im iffy abour and im not sure if id need the CEL

[Tedh98]

I would get a 40 and 42. A 45 would probably be a waste.

I have never used the stock needles, so I cant help you there.

[Julien D]

When you send the carb to RB, he will send it back with a new needle that is appropriate to his carb mods. Just stick with the stock needle until then. 155/45 is a good safe starting point if you're going to go through the jetting process yourself. You may end up as low as 150/40, but I wouldn't recommend starting there. If you go too lean, kaboom.

[KDX_Johnny]

okay so im back from the dealer they dont carry needles so im sticking with the stock one for now. As i ride the bike i am realizing that it is in fact extremely too rich. I came home with a 42 and 40 pilot and a 152.5 and 150 main. I will start with the 42 and the 152.5 first. Any objections before i play doctor? should i go buy a 45 and a 155?

[Julien D]

Nope. Give it a shot. Once you put the 42 pilot in, you can check for correct pilot size by using the method in our jetting sticky. Main jet takes a little more work, but pilot and needle clip setting are quite quick and easy.

[Tedh98]

Put the 42 in there and your AS will tell you if you need to go up to the 45. Very, very unlikely you will damage anything with a lean PJ. Not the case with the MJ though. I would get the 155 and work your way lean.

[KDX_Johnny]

Julien whats the method? or can you point me in the right direction of where on the sticky? Again with this clip setting thing? Cant i just screw the bastards in? And are you guys saying put the 42 in. test it and if its still rich THEN out the 152.5 in? I am not the best interpreter of words if you hadnt noticed hahaha picture do me very well!

[Julien D]

One circuit at a time. Pilot comes first, needle setting next, main jet last. Each circuit affects different throttle ranges. Give this a good read through before you get started. An important note, when finding "highest idle" while testing the pilot jet, do not continue to screw the airscrew out after the highest idle is reached, stop as soon as idle stops increasing. Kill the bike, and run it back in counting the amount of turns. The amount of turns will indicate if your pilot is too small or too large. Another note, you do not necessarily have to pull the carb. Loosen the clamps, and rotate it so that you can remove the float bowl. Jets can be accessed while the carb is still mounted. You can actually access the main jet from the drain plug hole, but the float bowl must be removed to access the pilot jet.


http://www.kdxrider.net/forums/viewtopi ... 105&t=1156


Good luck!!!

[KDX_Johnny]

She doesnt want to start for nobody right now... right now its 42PJ 152.5MJ and 3 turns out on the pilot mixture screw... idk guys ill get her to run for maybe 10 seconds but she sounds WICKED and bogged when i hit the throttle and revs when i release it. not a clue...

[KDX_Johnny]

thanks Julien ill do that now.

[KDX_Johnny]

okay so i did the first part. the bike is very snappy down low but feels like i lost power in the mid range. so i guess its too rich? should i go ahead and put the 42 in? because i know for a fact the 50 is gonna be WAY rich and the plug will be dark black (like they always are). Also once i do these setups are you sure it wont be too lean for my FMF that im ordering? thanks guys!

[KDX_Johnny]

yeah.... she wont run with the 152.5.... and if i do get her to start it sounds SCARY i can either put it back to stock (50/160) or run the 42 with the 160....

[Tedh98]

okay so i did the first part. the bike is very snappy down low but feels like i lost power in the mid range. so i guess its too rich? should i go ahead and put the 42 in? because i know for a fact the 50 is gonna be WAY rich and the plug will be dark black (like they always are). Also once i do these setups are you sure it wont be too lean for my FMF that im ordering? thanks guys!

You can't just do the 1st part and expect the bike to run well at all throttle openings. You need to do the entire process.

Where did the 50 PJ come from?