Hi everyone -
I've been reading everything here on the white spacer mod, carb adjustments, backfiring, afterfiring, etc. I can't figure out my particular issue. This has a lot of elements, so bear with me:
I just finished a Ryca build...so I have the shorty pipe with a K&N filter. The bike ran great before I took everything apart. I went up a size to 52.5 and 155 pilot and main jet. I did the white spacer mod with washers...currently I'm running a single, thin washer.
1. The bike won't start without the choke. Once it has started, though, I have to turn off the choke within 10 seconds or it starts a loping, missing, slow idle and dies. So - I pull the choke out, start it, then after 10 seconds, put the choke in and it ALMOST dies, but then it picks up to a nice-sounding idle.
2. When I'm riding it, it has great power and sounds great under acceleration in all gears. The second I let off the throttle, it starts crackling and popping and if I close the throttle and pull-in the clutch (coasting to a stop) the idle rpm drops way down for 2-4 seconds, then comes back up to normal (1200-1300)...sometimes the idle drops down so low after closing the throttle/disengaging the clutch that it dies. It drops, and then it recovers...every time I pull-in the clutch/let off the gas. If I don't pull-in the clutch but rather let it engine brake, the pipe starts making a loud "brrrappping" sound as soon as the throttle is totally closed.
3. I have adjusted the idle mixture screw up/down a bunch until I get the smoothest/highest-speed idle I can when the bike is warmed-up. The idle screw it turned-out 2.5 turns.
Here's what I don't get - If the idle mixture is TOO LEAN, I would think that the bike would idle better with the choke pulled-on...or at least for awhile...but if the bike is running and I pull on the choke, it IMMEDIATELY dies (even when it's cold). BUT I need the choke to start it for just a few seconds.
If the idle was TOO RICH, I would think that I could close the idle mixture screw all the way down and it would run better...but it doesn't - if I close down the idle mixture screw, it idles rough and then dies. It idles best with the mixture screw turned out 2.5 turns.
I have sealed the pipe/header with exhaust sealant. I have also checked for vacuum leaks using carb cleaner all around the carb.
Any ideas out there from you carburetor experts? The carb has a new gasket, new main and pilot jets, and a new diaphragm/slide assembly (b/c I couldn't get the little screws out of the old one, no matter how hard I tried
.
thanks everyone!
delaPlanet