Tuning for a screaming eagle. We'll deal first with the pilot jet. The 55 was too rich. It idled like crap at start up, i couldn't use the choke at all or it would die, and the stink of unburnt fuel was nauseating. So back to the 52.5. Heres the thing so far as this goes...I never have been able to "master" lancers carb tuning guide. With the 52.5 I can hear a distinct pickup in rpms past 1 turn out but they never go back down no matter how far I turn the mix screw out ( I can't physically tunr my screw out more than 4 turns. It just stops moving)so I can't really find that happy medium. Ive just settled with 2 turns out which did not cure the shutdown backfire with the stock pipe or with the SE and with the SE Im now getting a pretty burst of blue flame out the backend aswell as the backfire on shutdown. Im geussing rich but im new with carbs. Rich right? I feel like an idiot asking. So far as the jet needle, Ive got it at 1/2 spacer right now. Im gunna just ride a bit and check the plug. Feels nice as is though. Maybe go to 1/4 spacer. I get the distinct feeling no spacer would be too much and im just going to do a plug chop to check the main. There's a dandy stretch exactly 1 mi long right by my house for that little adventure.

I can use the choke with the 52.5. With the 52.5 nothing seems any different between the stock and SE except for the flames at shutdown.

yea...its tedious. Between trying to find out why i was running rich BEFORE i got the SE and now rejetting im sick of taking off teh seat and tank. On the upside Ive had the carb out so many time I can now have it out in about 10-15 minutes. Probably could do it in my sleep now.

I don't NEED the choke but my bike takes a few minutes to warm up. Always has. And the initially low idle on start up makes me uncomfortable so i have always used the choke for the first 30 seconds or so as directed by the owners manual. With the 55 the idle wasnt just slow it was borderline stalling and choke killed it instantly. I did rev it a bit to warm it up since the choke wasnt an option but the smell and small puffs of black smoke....ugh. As new to carb work as i am even i can tell the 55 is a no go.

Trad. method of idle circuit tuning is make sure engine's good and hot then:

• Turn idle speed as low as it'll go without stumbling.
• Adjust idle mixture/air screw.
• Repeat steps one and 2 until any adjustment of mixture/air screw causes stumbling.
• Turn idle speed back up.

BUT this won't work if the overrun bypass circuit is clagged up. There's a round cover on the side of the carb, under this is a vacuum diaphragm operating a bypass circuit. If like me you ignore this long enough the drilling in the cover that lets air in/out gets blocked and the bypass stays open when it shouldn't. Idle goes over-rich to the extent that choke isn't needed for the coldest start, exhaust blows white smoke, and you can turn the mixture/air screw in till it bottoms without making a difference.
Cleaning it - particularly the drilling in the cover - makes a big difference.

I feel you. I have been playing with my new vm for weeks lol (mainly because I work soo much). I used a dyno jet kit. It was probably more than lancers however it was quite easy to tune. Maybe I was just lucky. Anywho, keep at it. There will always be the occasional pop on shut down. Thats just little suzi passing gas lol. I finally got my bike running, however my idle circuit is still too rich. I have gone to the lowest pilot jet I can go to on my carb. I am gonna try playing with air mixture on saturday. If I cannot get it to ilde guess what? I have to pull the darn thing for the 50th time and bleed my pilot lol. That blue flame means its lean I believe. I used to have the same issue when I did not seal my new muffler very well. Have you tried setting the needle to a more lean position? i.e. the washer on the highest part of the needle? Goodluck with your tuning, some of us have a harder time than others.

maybe the 55 with a bigger airjet? that combo might give the result you are looking for.

52.5 pilot, half spacer (trying 1/4 tonight), 152.5 main and whatever the stock air jets are. 230 pilot and 45 main i believe. I went ahead and took another shot at tuning the pilot circuit. Its a bit better. Not a BANG even with the SE, just kind of a big fart but still has the burst of blue flame.