carbs jetting issue video colortune

[le_bucheron]

I just did my first ride after tuning. After the bike was warm, it run great. But around 1/4 to 1/2 throttle it coming to back firing. I can run perfectly the bike if during back fire I release a little bite the throttle and twist on again slowly. 1/2 to open throttle no problem.

Now I have:

Pilot 47.5 mikuni
Air jet 190 dynojet
Main jet 128 dynojet
Sync and colortune twice

In the dynojet instructions they say to use 138 main jet. I found it to big... The stage 3 it's for pods mod and after market exhaust. I build my exhaust by using supertrapp headers 4-1, add spliter 1-2, finish it with 2 slip-on kerker serie k from a vmax. I found it more quiet than my cheap 4-1 exhaust.

I running 2 times short of battery during my test and tune. Also I add a car battery over my balistic one.

What is next step?

-Be sure my charging system run great?
-Use bigger main jet?
-move my needle clip (dynojet)?

[motoman]

I just did my first ride after tuning. After the bike was warm, it run great. But around 1/4 to 1/2 throttle it coming to back firing. I can run perfectly the bike if during back fire I release a little bite the throttle and twist on again slowly. 1/2 to open throttle no problem.

Now I have:

Pilot 47.5 mikuni
Air jet 190 dynojet
Main jet 128 dynojet
Sync and colortune twice

In the dynojet instructions they say to use 138 main jet. I found it to big... The stage 3 it's for pods mod and after market exhaust. I build my exhaust by using supertrapp headers 4-1, add spliter 1-2, finish it with 2 slip-on kerker serie k from a vmax. I found it more quiet than my cheap 4-1 exhaust.

I running 2 times short of battery during my test and tune. Also I add a car battery over my balistic one.

What is next step?

-Be sure my charging system run great?
-Use bigger main jet?
-move my needle clip (dynojet)?

New battery, and check that the voltage is the same AT the coils as it is at the battery, key on both checks. No change should be seen.

[jetmechmarty]

New battery, and check that the voltage is the same AT the coils as it is at the battery, key on both checks. No change should be seen.

He ain't kiddin'! Do not tear into your carbs before you're sure they don't have an electrical problem. I just went through this with mine. My low throttle setting issues were cured by cleaning a few connectors and the kill switch.