Some jetting issues I need clarified please.

[fatty_k]

Ok, I am a newbie at jetting but I get the basics. I had a 145 main in and I did a WOT plug chop; it showed lean. I put in a 150 and it looked a little tan, but still a little white. It sounds like its running perfect on top (no sputtering, or bwahhhh'ing) but it dosnt seem to pull very good on top, despite the fact that i have the FMF kg 30 pipe. I am wondering if I should put a richer main in still, just to get the plug nice and tan and be on the safe side. I was running a new BR8EG plug at the time. I also have a burrbling at about 1/4 throttle. I raised the needle all the way to the top position, it helped a bit, but it is still there. My plug looks perfect after I do a 1/4 throttle chop. Should I go to a leaner needle? And if so, how much do they usually cost?
Thanks a bunch.

 

[LWilson250]

I would try going up one more main and dropping the needle.
Then mess with the pilot jet, sounds like you need a slightly larger one.

Lee W.

 

[OLD-N-SLOW]

fatty,
Which bike? If 220 what carb? stock or 35mm?
When I get confused i just go back to stock settings and start over.
1/4 throttle, steady, holding speed blubering sounds like a rich pilot.
When you say "raised the needle to top position" please clarify.
Pointy end of needle being bottom and the end with the grooves being top.
#1 position would be the very top groove making #5 posistion closest to the
sharp end. Want to help, just a little confused.
Steve

 

[canyncarvr]

O&S
You're not confused at all (but..you knew that). You're probably familiar with GIGO? Well, fuzzy-in fuzzy-out gets you the same result.

fatty: Plug color checks are often incorrectly done. Be sure yours is not. The color you're looking for is where the insulator meets the shell, or the flat just below the threads. Better safe than sorry is my personal line of thinking. I'd rather lose the .00125 ponies gained from perfection and run a bit on the rich side. 'A little tan' is open to personal interpretation.

Other than that, not enough info. You've probably stated all your bike's parts/refinements before, but I certainly don't recall them.

There's a difference between burbling and 4-stroking. With no load you're going to get the latter @ 1/4 throttle. That's your bike making happy noises!

Is it time to go riding, now?

 

[fatty_k]

Oh sorry guys. Its on my 1998 220 with stock carb, air box lid gone, FMF kg 30 pipe, FMF turbine core 2 silencer, RAD vlave. I raised the needle to the top position, meaning the farthest groove away from the pointy end. The #1 groove.

canyncarvr, I realize how to do proper plug checks, and I think I am doing them correctly. After you said the difference between 4 stroking and brubling, I guess it is running fine, as it seems to only have a rough spot when there is not much load on it. I am thinking of going to a 38 pilot from 40, which I have in there right now. See if that clears anything up. I will also try a richer main, just to be on the safe side.
I hope this is a little more clearer. Thanks for all your help.

 

[Fred T]

Fatty
On the 220, try this combo. 148 main, R1173 in #2, 40 pilot. Adjust A/S to flavor. I ran a 42 pilot last year. I didn't like the Stock needle, I suggest a CEL from sudco in #3. If your afraid to lower the main keep the 150 in it and try the other setings. Tell me what ya think. (BTW-#2 is second slot from the top. I suspect your lean ness is bacause of needle position and not main jet size.

 

[fatty_k]

Ok thanks, I kept moving my needle clip position up (to the opposite the pointy end) to try and cure the sputtering at 1/4 throttle. It didnt help. I will try your recomendations!
Thanks

 

[canyncarvr]

DRN hates me...they don't tell me when threads are posted to anymore.. :(

re: burbling at 1/4 throttle (besides the 4-stroking/too rich question)

..is right in the 'straight diameter' circuit of the carb (just a BTW)

That said, I don't thing a 39.95mm needle will ever be on clip #1. (That's an 'N' needle)

re: 'not too good on top'
The H-U-G-E difference between FredT and fatty_k's setup? Carb size!! The OEM 220 is repeatedly defined as 'weak on top', isn't it?

re: 38 pilot
Probably the wrong direction. Fishhead made a note of import awhile back..a too lean pilot will show up as high (runaway like) idle on cold/choke start. I know that to be true from my own observations (and dinking with stuff too much!).

fatty......don't give up on that AS! You're coming off the AS right @ 1/4 throttle. Give it a 1/16th tweak...ride it for awhile. Looking back thru this thread, the only AS ref I see is from FredT.

For sure...'to flavor' !!

 

[Fred T]

Canyon
I was referring to the stock 33MM carb BTW. My set up last year at 1200 Ft was 42/R1173 #2/ 145 and A/s about 3/8 out. That was in the heat of summer and when it cooled down I jumped up to a 148. FMF Kg 30/boyesen 607 reeds and airbox mods only. MX 2T@40-1 with 93 pump gas. Now with RB carb I'm running differently but I never mentioned that set up in this thread. Just to clearify.

 

[canyncarvr]

Sorry...it's my inference that was wrong.

I didn't mean to imply that your jetting recommendation wasn't applicable.

One of the complaints being 'doesn't pull very good on top' is something I understand to be the nature of an OEM 220 (33mm). Fatty_k isn't ever going to get the response on top compared to a 36mm equipped 220.


Look what fatty has to look forward to!!

 

[fatty_k]

Thanks for all your help guys! I will continue to persue my quest for the right jetting. I love playing arund with different carb settings, so that should keep me occupied for a while. :) When I get some money I will do my suspension first, then my send carb off to RB or Fredette!