rich or lean?
Posted May 28, 2003 - 03:38 PM
So I'm back to obeln #3, with stock settings and not sure were to go from here. I ride in Gaylord Michigan, I think Im around 1000ft with mods in signiture. From looking at older posts, Im just getting more confused. With the uncorked pipe and air lid removed you would think things would be leaned out, but when I went to clip 4 it jsut ran like hell. Also when I start my bike cold I can pull the choke in right away and it will run. Is that a sign of rich pj. Any help would be greatly appreciated.
Posted May 28, 2003 - 04:15 PM
Is that what you had in there to begin with?
One thing I see is that you are making too many changes, so you can't isolate what any one thing is doing.
This sort of causes the second thing, which is that you've tried everything and the stutter was still there, so maybe it isn't a jetting related issue.
Posted May 28, 2003 - 08:31 PM
Posted May 29, 2003 - 04:18 AM
38PJ/65PAJ/EKN#4/160MJ/160MAJ/1.0 turns fuel screw.
You might consider playing around with your airjets...as you didnt mention what they were (it's not just the fuel jets that matter). I run a 38PJ/65PAJ combo on the pilot circuit...a 35PJ/50PAJ or 40PJ/75PAJ should work as well...
I know that there's quite a few folks running a 35PJ/50PAJ/EMM#5 around, but they're at sealevel...and I dont want to tout a setup unless I've had a chance to try it myself. Food for thought...
Posted May 29, 2003 - 08:53 AM
I was looking at older posts and found that the ekn needle is a half a clip leaner than the eln. So if I was on clip 3 with ekn, it would be like clip 2 and a half with obeln. I was thinking of trying ekn.
Posted May 29, 2003 - 09:59 AM
- Wide open in 4th gear, then let off the throttle. Check for either backfiring, popping, or none. If backfiring, PAJ is too small for the PJ...if popping, PAJ is too large for the PJ...if none, then you've got a good PJ/PAJ ratio. I suggest the Sudco adjustable pilot air screw...as you dont have to buy PAJ's anymore...$15 for the screw covers all the PAJ's you'd ever want to throw in there. Find their 800 number to order...
I think the "N" needle should be about right...so I'd concentrate on the PJ/PAJ ratio.
Once you've got that down, play with the needle/clip position. BTW, you've got it backwards regarding EKN vs. ELN. EKN#3=ELN#3.5 ...the EKN distance from top of needle down to where its diameter is 2.514 cm is slightly less than the ELN...so you have to "raise" the ELN needle slightly more by going up 1/2 clip position (to 3.5 in my example).
Anyway, at mid RPM's and constant throttle, check if the bike is "surging". If so, you're too lean on your clip position. Also, if mid RPM acceleration is sluggish, you're too rich on clip position. When doing this, keep the MJ constant, as it has an affect on mid RPM's.
Then, verify the high RPM's the same way as the mid RPM's to test your MJ. If you change your MJ setting, you'll have to go back and re-test your mid RPM's, as you've just changed that circuit somewhat.
Finally, figure out what MAJ works best. I found that my bike accelerates faster (rev's out faster) using a 160MAJ vs. the stock 200MAJ. Not a biggy here, just personal preference.
Anyway, that's what I would do. I can say that what I have is somewhere in the ballpark...so perhaps start there. Our bikes are setup very similarly (see my sig below)...except that I've done the BK mod to get rid of that 1/4 throttle bog.
FYI, you dont necessarily have to buy another needle to switch from ELN to EKN...just go find a very small, thin washer...that's about as thin as 1/2 clip position on a needle...and you can use that to raise the needle to equate the two. Or just buy another needle...
Good luck! And keep me posted on what works well for you...as I'll be having to do the same testing here soon when work calms down for me and I get some time...
Posted May 29, 2003 - 04:55 PM
Posted May 29, 2003 - 07:36 PM
Thanks for the info. It will be a couple of weeks before I get back up north to do more testing. When you talk about the pj/paj combo, do you mean to replace the paj instead of pj? Also is the poping sound when running lean really loud and distinict like a backfire. What exactly should I be listening for.
PJ/PAJ: Not sure what your question is exactly, but the two jets sort of go together. I think what LarryCO was talking about was the tendency for the Air Jet to really affect higher rpm jetting, but you also need to realize that if you change the fuel jet more than a size or two you will likely need to change the air jet in the same direction (larger-larger or smaller-smaller, they go together). So, if you have the best off-idle throttle response on the planet, but you are besieged by annoying popping on decel you need a smaller air jet (low throttle=pilot circuit, the fact that it is a high rpm problem only means it is air jet, therefore it is Pilot Air Jet).
The popping we are talking about is a common thing with a modern thumper. If you want to get technical it is a backfire, but it sounds like a series of popping noises that vary in volume. A few here and there is normal, but if your bike always pops, and pops a lot under decel, and you are happy with your idle and pilot fuel mixtures, then the PAJ is what you need to be looking at. For guys like me and LarryCo at higher altitudes and therefore smaller pilot fuel jets this is an issue we were very happy to get sorted out(at least I was).
Hope this helps.
Posted June 02, 2003 - 06:25 AM
so i would blow out the jet that you can see in the front face of the carb marked #75 or #100 (the other one says #200, so that's how you know!) the take the carb apart and do the lot obviously. when you put it back together try the PS underneath first at 1 turn from closed and then 1.5 turns.
this all might help. the next stage is to go down two PJ's if it made no difference.
by now we should be getting a clearer picture and so report back here with your findings.
Posted June 02, 2003 - 11:47 AM
Posted June 02, 2003 - 01:42 PM
Posted June 03, 2003 - 09:25 AM