Pilot mixture screw adjustment - can it be performed while on the bike?

[EasyTargetRN]

2003 R* with K&N full circumference air filter with flat cover plate, V&H long shots, can't speak to the jetting as the prior owner passed away and his brother sold the bike to me.

I have to keep the choke pulled out 1/2 way or she stalls. Also bogs a little bit from a stop, steady lower speed riding produces backfiring some stuttering but resolves when getting on the throttle. Checked the throttle body, vacuum lines for leaks, thinking its the PMS. Searched the forums for an answer to PMS adjustment w/o removing the carb. Haven't found anything conclusive. I have the airbox off and I think I see it at the base of the carb between the bowl and the cylinders. Hoping this resolves my lean issues.Can anyone share a pic?
Thanks

[Lug Nut]

Barons makes an adjustable PMS screw thatallows for on-the-fly adjustment very easily. However a couple of us have had these things vibrate loose and fall out. You really need to drop the bowl remove the pilot and main jet to see what they are. We can let you know precise jetting for your bike. And honestly once the jetting is done correctly and you set the PMS at 2 and 1/2 turns out you really don't need to mess with it again

[brianmac]

before installing barons PMS, stretch the factory spring a bit longer, this will prevent it from vibrating out or lossening. it helps her in central FL, in winter, we can go from 85/85 to 40/40 temp/humidity overnite, and back.

[Ratl]

You can adjust the pilot mixture screw while you’re riding, however, the only thing that really does for you is adjust the idle speed. Idle speed should be around 900 RPM on the road star. It is a black knob at the end of a cable, usually under the carb.

Since you say you checked for air leaks, it will be hard to advise you about the issues you’re having without knowing more about how your bike is setup, particularly the jetting. Double check for air leaks on both the intake and exhaust systems. If there are none, check the spark plugs condition to see if it’s running too rich and let us know what you’ve found.

Ratl.

[EasyTargetRN]

I tried the adjust the idle using the knurled knob below the air cleaner. It seems seized and didn't change the idle. Next logical step is to pull the carb?

[Shores]

Lube the idle mixture knob and cable. This is different than the PMS which is on the carb.

[davej]

stop playing with it and take the carb apart clean it ,free up the idle adjuster(Knurled knob) and let us know what jets are in there. Tis will also give an opportunity to check the intake manifold, it is probably full of cracks. Doing this will make it run new again. Anything else is just wasting time.

[EasyTargetRN]

Sounds like my weekend project. Will I need a rebuild kit and jets/needle? Haven't played with a carb since the Holley 750 on my Galaxie. Considering the K&N filter and V&H long shots, what type?

[Dr. D]

Here's another to add to your list Shores: I haven't been able to source an 066V or 067V anywhere.
RA-068V - round, 0.813" offset, 4" deep, 6" diameter. $59.00 from K&N.

I have this filter. It sticks out about as far as the factory box. If you're tall (I am 6'2" and relocated the floorboards 3" forward), it won't interfere with your knee.

[Shotround]

they're no longer listed on the kn site anymore. im hoping they'll bring something back when things settle down.

[Shotround]

what about the rc-850 and rc-860. flange inside diameter is 62mm. the ra-068v has a flange inside diameter of 65mm. also, flange length is shorter at 16mm vs 22mm.

RC-0850 2.438 in (62 mm) 2 in (51 mm) 5.125 in (130 mm)
RC-0860 2.438 in (62 mm) 3 in (76 mm) 5.125 in (130 mm)

it's probably going to be a tight fit at the flange.

[EasyTargetRN]

Duke Big thanks to Duke for the intact airbox, one less thing to worry about.

[davej]

there is really not a rebuild kit. A can of carb cleaner will be needed but keep it off the rubber fuel bowl gasket. Some carb cleaners will make it swell instantly. Clean everything real good and take note of the 2 jet sizes and if it has an adjustable needle in it. don't adjust the float, that is where most people mess things up. let us know what jets you find and if it has the adjustable needle we need to know what groove the clip is in. also make sur you don't lose the small O-ring gasket on the fuel bowl. There is the big bowl seal and a 2nd small oring to seal the acc pump passage that may fall out when you remove the fuel bowl..

[EasyTargetRN]

Thanks davej the tech article on the forum is an excellent resource as well.

[Sharpman66]

While you have the carb out check the condition of the enricher cover. If it's cracked it should be replaced with an aluminum one.

[EasyTargetRN]

Enricher cover? Guess I'll need to search for that once I pull the carb. Where did you get the star cover?

[EasyTargetRN]

nvmd, AKA accelerator pump cover...

[EasyTargetRN]

Finally had time to work on the R*. Carb disassembled, cleaned, and recommended jets installed. Plugs changed. Before I reinstall the carb is the pilot mixture screw @1200 in the picture? Seat then 2.5 turns out?
thanks

[DEEPHATE]

That's what I did, runs great.

[Bmblank]

Just curious, where did you get the recommended sizing for your jets? I think I’m in a similar situation with my 2001 road star 1600. Cobra long tube exhaust and a RK-3905-1 K&N full circumference intake. Seems a bit lean with just the exhaust (backfiring on decel, could be AIS as that is still hooked up?) and was un-ridable with the K&N intake. Couldn’t get above a certain rpm without choking out so I put the stock back on for now. I haven’t pulled apart the carb yet so don’t know the sizes yet but I assume they are original. Was it a member or a website that you got the recommendation from? Are larger jets necessary or can I just fatten up the fuel/air with PMS adjustment?
Thanks, Bryan

[Shotround]

I believe the recommendation is to also remove the inlet filter.

[EasyTargetRN]

Everything back together, started w/o pulling the enricher. Idled at about 900, responded well to throttle. Shut her off after idling for 5 minutes and went to install the airbox and gas is leaking from the bottom of the carb.
Double checked all the screws before installing…
argh

[Shores]

Tap the float bowl with a screwdriver while it's running to see if you can release the float. It might be stuck down.

[EasyTargetRN]

Took everything apart, bowl gasket may have slipped, and float needle seemed sticky. Everything back together and no leaks
huzzah!
thanks all for the wisdom

[Kevin Di]

Since you are all on this topic I’m unsure if this is my PMS… ?

[Duke]

Yes, that's your PMS. Start with 2 1/2 turns out, then turn to find the highest idle, then 1/8 of a turn out. It's set.

[brianmac]

if there is a screw in the hole, Its probably PMS,FUZZY PIC, idle mixture screw. in GENTLY for leaner, out for richer, at low RPM mostly. ADUSTING THE PMS , often REUIRES a corresponding idle speed adjustment. do it when ENGINE HOT .
is your screeen name in reference to the RNs that were charged criminally for making OTJ mistakes. ???

[Kevin Di]

Yes I did jump into RM post only because you guys were on that topic. The issue I’m having with my bike is I release the throttle and I’m getting some backfiring through the exhaust as I’m cruising down the road… Thank you Guys I will keep you posted on how I make out.

[SbTx_Rider]

Generally all exhaust backfires are caused by exhaust leaks and the AIS system. Is your AIS still on your bike? If so, search the site, plenty of threads on how to delete the AIS system.. I think it might even be under tech articles. Also, make sure exhaust ports are good and any exhaust pipe joint is sealed. Fresh air enters the exhaust and causes the unburnt gas to ignite, causing the backfire.

[EasyTargetRN]

if there is a screw in the hole, Its probably PMS,FUZZY PIC, idle mixture screw. in GENTLY for leaner, out for richer, at low RPM mostly. ADUSTING THE PMS , often REUIRES a corresponding idle speed adjustment. do it when ENGINE HOT .
is your screeen name in reference to the RNs that were charged criminally for making OTJ mistakes. ???

If you're referring to me, no, that's a "gamer name" my kids gave me a loooong time ago...I once tried to play Gears of War with them...I never made it that far before being dropped hence the name EasyTarget, RN is what I've been for 30 years.