Does dirty air filter on carb motors induce a rich condition?

**racefactory** · 13th July 2011, 16:55

I know on a fuel injected motor that the air flow sensor will just inject less fuel for a dirty or restricted air filter but on carb bikes will it just run rich instead? Or less fuel will be sucked through the venturi for the reduced air flow too?

**Laava** · 13th July 2011, 17:33

Yes they will run richer.

**Motu** · 13th July 2011, 17:41

It depends on how the float chamber is vented. If it's vented to the atmosphere then it will run rich. If it's vented into the airhorn (on carb side of aircleaner) then it won't go rich....although at full throttle and max rpm it possibly will.

**racefactory** · 13th July 2011, 18:47

So what about a Keihin FCR carb? Do you know how that's vented?

**FJRider** · 13th July 2011, 19:20

As a general rule ... yes ..

**sinfull** · 13th July 2011, 19:43

It's all good ! Don't worry be happy ! servicing is for rosi's !

**FROSTY:Me** · 20th July 2011, 16:47

OP think through your question.Its not really rocket science is it? less air same amount of fuel and..... Incidently even FI engines have their limitations when it comes to clogged filters.

**DEATH_INC.** · 20th July 2011, 20:27

Frosty is right about efi motors too, they mostly use a very simple efi system that doesn't compensate for jack. Our bike Systems are very basic.

**Motu** · 20th July 2011, 20:42

Ah,efi engines use an airflow meter of some sort - it measures how much air the engine is using and gives the appropriate amount of fuel. The condition of the airfliter makes no difference to fuel economy.