Well, after weeks of tinkering, I am convinced that my jetting and PMS are pretty good. Power from idle to wide open, no backfire, not coughing, no lurching, no hesitation. I even manufactured a remote PMS adjustment device that is pretty cool. My problem/ question is, why does the bike have 2 distinct personalities? "Nice roadie" runs unbelievably smoothe, quiet, powerful. Very pleasant in and out of town and sweet sounding. "Nasty roadie" idles rough, has a very loud and annoying crackle from the pipes, (loud to the point of pain while climbing) sounds kinda like sputta putta puttaish going down the road.
I have tried to note when nasty happens and for a while I thought elevation or air pressure changes were the culprit but I have noticed the change while nothing changes. I could pull in for a bite to eat with nice roadie and when I fire her up to go home, it is nasty. Also, important to note is that it doesn't seem to matter if the bike is warmed up or cold. It really has me wondering if something else is just not right. Could anyone give me an idea what to look for?

I am running with K/N BAK, Mega cone, High compression pistons, stage 3 competition ignition box, ported/polished heads, 160 main, 50 pilot needle on 3+1 washer and PMS at 3.

I would really appreciate some help.

Thanks,

Doug

Tough to pin it down if it's sporadic.

I suspect you may be getting some carbon buildup periodically which 'blows' itself out when you ride. Most likely from the large pilot .... but if it's running great most of the time it's tough to start changeing the jetting.

Doc

Thanks Doc!

I read a lot of guys have the stock pilot in there (I think it is the 35 right?) And that is the only configuration I haven't tried. Simple enough to give it a whirl. Probably just have to tinker around with the PMS a little then. We will see what happens.

Thanks again.

If you just put in the stock pilot you will be too lean with the 160 ... the bike will run worse as you start leaning out the pilot. For your setup the pilot is accommodating the lean main.

I would guess that with your setup you probably are getting some gas smell at idle?

Doc

Doc,
Yes, just a bit of gas smell at idle. Yesterday after signing off it really ran fantastic for about 65 miles, then the problem surfaced again. I think it is solvable. Just a little more tinkering and hepful hint from you should do it. My shop guy says "..thats the way they are and I won't be able to completely solve it. He is all about fuel injection.

We'll see..

Thanks

The smell at idle is due to the large pilot you are using.

I guess you have a decision to make .... if you're really satisfied with how it's running then leave it alone. If you want to try and improve it then you need to tinker.

If you want to tinker then ....

Use some top end cleaner (WWO, Seafoam, RingFree, etc.) to clean out the system by:

Remove air cleaner. Turn the idle up to about 1500. Lightly spray some cleaner through the carb for 30 seconds without stalling the motor. Reduce idle to stock and spray enough to stall the motor. Leave overnight and drive hard the next day until hot. Should take about 2 miles to get ride of the backfiring and flames.

Then rejet:

- main 170
- pilot 35
- needle on 5th groove from top
- PMS - 2.5 to 3 turns out

Do the WOT test and see how it runs. Change main if needed and once the main it OK, change the clip to the 4th. Refine the PMS by the in/out method. Test.

From there on it change the needle setting and PMS to find the optimum setting for you.

As you have leaned out the pilot you may also have to play with the accelerator pump to compensate for some off idle hesitation but I'd do that last .

Doc

Hey Doc,

Thanks.
I am good on all but the "play with the accelerator pump" part. No clue.

I had already changed the pilot to 35 and the main to 170 and 3 on the PMS based on what I learned by checking everyone's profile that listed jetting. Then I read your latest reply and took a test ride to buy some seafoam. WOT was pretty good but off idle and stedy speeds were rough with pops in the carb and through pipe. On acceleration, it ran pretty good.

biknski

Hey Doc,

Just wondering what you thought my next move should be. As I noted in last post, I am not sure about the accelerator pump and how to adjust it. I think I will start with moving to the 5th groove and see if the pops and coughs stop. The off idle has me concerned.

Thanks

Where's the clip on the needle now ... 4. Yes you can try that. Remember to change only on setting at a time. It's easier to determine the effect that it has.

The accelerator pump screw needs to be turn in or out. Using the same reference point, try turning it in one turn and then out one turn and see which way it runs better, then just keep adding another turn until it's better. Some folks have turned it all the way in and put the nut on the back side but it's different for different folks.

You might also want to verify that you float level is not out of wack and that you don't have any air leaks around the manifold to carb to head joints.

Doc

Doc,
The needle is at 3 + 1 washer now.

Just to be sure, where is the accelerator pump screw? There are a lot of screws and I don't want to screw anything up!

Biknski