Troubles with Scar Method

[2ndchildhood]

Today I tackled the Scar Method because I was running lean after 1) removal of the PAIR Valve, 2) drilling out my pipes with (7) 1/2" Holes. Noticed that my bike was still decel popping and dhoped the Scar Method would fix it.

What was done: Added 1 washer; trimmed the Jet Needle Holder nib by 1/2; trimmed the compression spring to a little over 5 1/16"; removed the A/F Valve by first loosening the boot going to the manifold and tilted the carb so that I could remove the A/F screw; notched the A/F screw and returned the 1) washer, 2) spring and A/F screw back into the housing; screwed the A/F until it lightly snugged... then backed out 2 & 1/2 turns. Reassembled the carb and then the air box and tank.

Symptoms: at first, wouldn't run without full chock; adjusted the idle and it idled; pushed the bike out of the garage and tried to advance the throttle and the bike sputtered and chocked... tried again and same result. Tried to use the choke and got enough revs to move back into the garage... barely.

I checked tank connections and all were properly attached. That's as far as I went... hoping that someone will be able to help me narrrow down the alternatives... my thought are 1) vacuum connections to carb; 2) A/F screw; 3) compression spring?:hmm2:

Any help/thoughts will be appreciated!:D :D

[Retro Rich]

Did your idle screw knob get turned in too much? That does happen sometimes when you start twisting the carb around/moving it out of the boot. I'd also check your vacuum lines connection at the carb and at the petcock, make sure the tank vent line is hooked up as well.

Sorry about the delay; let us know if you need more help.

[2ndchildhood]

I checked everything out Sunday. The only things I found were; 1) I might have had my vacuum baldder pinched in the cover... I fixed that; 2) I think I hadn't tightened the A/F screw enough and had a too righ mixture. Unfortunately, wjen I removed the A/F screw again, I dropped it and have a new one on order... shoudl be here Friday and I'll be in touch after I get everything back in place... live and learn! I'm not too pissed about the $17.00 lesson... could have been much worse had the stealer fixed it for me...:) Thanks for the help, Rich and Charlie D!

[2ndchildhood]

OK, I installed the new A/F screw, set it at 2 1/2 turns out, put everything back together, still have decel popping! I'm beginning to think I have an air leak in my exhaust and it's not a lean condition after all. In retrospect, the spark plugs looked 'very good', based on the chart on Bare's homepage.

Should I replace the crush gaskets? I haven't tried to detect if there's an air leak by using a cigarette (my neighbor smokes but haven't found him yet). The urgency of this thread is now way down... no urgency at all at this point. The other option would be to continue adjusting the A/F screw (1/8 turn at a time) but today, that sounds like a lot of work! Maybe tomorrow.

Is there anything else I should look at? Could it be valves out of adjustment, for example? I would have thought that the plugs might show if that were the case...

[Retro Rich]

Sorry about the delay in responding; if you haven't removed the pipes at all, then you most likely shouldn't have an issue with the crush gaskets. When you did your Pair Valve removal, did you use block of plates or just plug/cap things off? If you just plugged/capped, sounds like you could have a leak somewhere around there so I would recommend ordering the block off plates.

How do your plugs look after running it around 20 or so miles? If they look ok and aren't fouled, take the A/F out another 1/8 of a turn at a time and test it out, see how it does. Sounds like if it's not a vac. leak in the PAIR system removal, then you still could be a little lean.

Post back with your results/any more questions.

[2ndchildhood]

My front exhaust was loose at the crush gasket... I've never had them off tho... I used the block off plates for the PAIR removal. I rode today... it seems like I have more guts at the low end and, the pipes sound better... I had only a little decel popping today... I'm going to screw the A/F out another 1/4 of a turn... but I'm happy with the results!

Thanks for your help... there's no more urgency!:) :)