OK...so, first of all, sorry for all the posts, but I am trying to keep things in the right forums and where they go..haha

Last night, I put on my new exhaust, LA Chopper DoubleStack CurveDD. I also did the HyperCharger Pro-R. After getting what I think is most of the install right (it was tough, and still not sure on all the vents and hoses) I did the carb settings. I used the recommended jet kit and settings from Kuryakyn and I wanted some of you gurus to tell me what your thoughts are, as I know nothing about carbs, but am trying to learn it all.

Main Jet 182.5
Needle (clip in 2nd groove from top, white washer under that)
Pilot Air Bleed 1.3
Pilot Jet 37.5
PMS about 2 turns (this I know needs to be tweaked)


So, I get it all on, it seems to run ok, idles good, decent response for what I can tell...but definately getting decel pop/backfire and if I blip the throttle, shoots a nice flame out the bottom! I am guessing that will get fixed as I play with the PMS???

Anyway, carb guys, let me know your thoughts. I know they are all different, but learn me

TIA

It will take more than a PMS tweak to fix.

For eqivalent setups we generally recommend ...

- the Mikuni 170 (you have a Mikuni jet kit)
- 5th clip from the top with the white spacer and silver washer underneath
- stock pilot (#35)
- PMS about 2.5 - 3 turns out

Do the WOT test to dial in the main ... you may need a 167.5.

The move the clip to 4th groove.

Test again.

Doc

ok..the kit only came with the 182.5, so I guess I need to get another kit? Can you get those locally usually?

oh wait, no it didn't...they are all there. I had moved them to get them out of the way into another bin. my bad.

OK, Gurus.....

I got home and went and tore everything apart again. If nothing else, I am getting damn good at tearing the bike down to get the carb out

I got out my jet kit and the smallest Main I had was a 175.

So here is where it is now, with Docs input:

main: 175
Clip on #4 with washer and bushing
Stock Pilot: #35
PMS 3 turns

Now, I am still backfiring, and hard, like shotgun blast if I let off throttle hard.
My idle is rough, if it doesn't kill it. I adjusted the idler, to raise it some. 3 times it died from start, just rolling on throttle would kill it.

I loosened the pipes and retightened in case of leaking, which I have listened and felt all over and cant hear or feel any.

Help

Jason how about a pic of those new pipes.....

collector714 wrote:
Jason how about a pic of those new pipes.....
Now that.....I can do

Pipes and HyperCharger PRo-R

http://i161.photobucket.com/albums/t212/jcoleman19/Bike/curvedd.jpg

Jason,

I also had Kuryakyn Hypercharger. Did you removed the AIS? Your problem worsened due to the change in the PILOT JET. The stock #35 is to small once you replace the air box. You have a 37.5, and still get it, so you need to go up to a #40.0, and you will probably fix it. Get the pilot at your local Yamaha shop. If you didn't remove the AIS, then the 37.5 should have worked, but sometimes the backfire and pop comes from the AIS. I never had a problem with the needle set at where Kuryakyn recommended. Remember, the Kuryakyn kit is based on leaving the AIS installed, since it's illigal for them to show you how to remove an immissions part.

The 175 main will help with milage, depending on your sea level. Most of the "decell" pop comes from the Pilot and Idle Jets being to small. Just change that pilot jet under the top cap of the carb, and you should be happy. If it doesn't work, it's only about $5 bucks and 30 minutes. It ain't gonna kill ya!

Enjoy,

Russ

Russ...two things...THANKS for the info, and the sig pic wowsers.


I do have the AIS removed...so I will definately try this.

Doc, sorry I forgot to mention that if you are now saying "why didn't he say that"

As for mileage, I am not too worried about that, I mean, 35-40mpg and above is fine, so performance means more to me than gas mileage. Is there a best setup for that?

You can't go at jetting haphazardly ... it needs to be regimented .... slow and steady. One thing at a time .... get that right and then move on.

Your backfiring is due to either an air leak (probably not if it's right after you let off the throttle hard) or a too rich condition. I suspect the 175 is too rich of a main but .... did you the WOT test to verify? See my first post to you.

Doc