Coasting Enrichener Circuit" or the "Anti-Backfire Valve"

29-04-2004, 08:30 AM

Anybody done this, Dose it apply to UK Bikes, sounds a bit naughty, and sounds like it might make the bike bark even more?????

Cut and paste from Web....dont know these guys at all and some links dont work.... but maybe some of you petrol heads have heard of this Mod... What dose it do exactly????

http://www.jfairstein.com/m900.html

Dave Mordecai recommended this modification to me, and it works well on my 1994 M900 with 38mm Mikuni BDST carbs. To eliminate the abrupt throttle cut-off when decelerating and to make the throttle modulate better off idle, disable Mikuni's Coasting Enrichener Circuit in the carb. (Note: read the entire carb section of the M900 shop manual -- these carbs are complex.)

Follow Scott Nelson's instructions to get to where you can remove the diaphragm covers off the carbs.
Next perform Dave Mordecai's modification:
Remove the carb diaphragm covers.
Remove the 1.4 Pilot Air Jets under the diaphragms.
Remove the .60 Pilot Air Jets in the carb intake and replace them with the 1.4 jets from under the diaphragm.
Solder the .60 jets closed and install them where the 1.4 jets were under the diaphragms. I found some 4mm Allen set screws that I used to replace the jets rather than soldering them closed.
Put everything back together and readjust the idle.

30-04-2004, 10:28 AM

Sounds like a recipe for disaster to me...

These guys must be far out on acid man... far out.....

The American bikes do have some pretty weird and wonderful pollution control devices though... perhaps smoking the contents of the fuel vapour cannister helps you feel better when riding?

l.t.

29-04-2004, 08:30 AM	#1
JJCool Guest Posts: n/a	Coasting Enrichener Circuit" or the "Anti-Backfire Valve" Anybody done this, Dose it apply to UK Bikes, sounds a bit naughty, and sounds like it might make the bike bark even more????? Cut and paste from Web....dont know these guys at all and some links dont work.... but maybe some of you petrol heads have heard of this Mod... What dose it do exactly???? http://www.jfairstein.com/m900.html Dave Mordecai recommended this modification to me, and it works well on my 1994 M900 with 38mm Mikuni BDST carbs. To eliminate the abrupt throttle cut-off when decelerating and to make the throttle modulate better off idle, disable Mikuni's Coasting Enrichener Circuit in the carb. (Note: read the entire carb section of the M900 shop manual -- these carbs are complex.) Follow Scott Nelson's instructions to get to where you can remove the diaphragm covers off the carbs. Next perform Dave Mordecai's modification: Remove the carb diaphragm covers. Remove the 1.4 Pilot Air Jets under the diaphragms. Remove the .60 Pilot Air Jets in the carb intake and replace them with the 1.4 jets from under the diaphragm. Solder the .60 jets closed and install them where the 1.4 jets were under the diaphragms. I found some 4mm Allen set screws that I used to replace the jets rather than soldering them closed. Put everything back together and readjust the idle.

30-04-2004, 10:28 AM	#2
superlight3 Guest Posts: n/a	Sounds like a recipe for disaster to me... These guys must be far out on acid man... far out..... The American bikes do have some pretty weird and wonderful pollution control devices though... perhaps smoking the contents of the fuel vapour cannister helps you feel better when riding? l.t.