filter

[foxracingkid22]

is it better to put a filter on the carb itself then to have it up in the box. and will it change anything? is it safe?

 

[Herpderplol]

I wouldnt say its "better" but you will get better airflow

If you have a heavily modded engine, you need more air (mainly porting)

You will have to bump your jet 1-2 sizes up

You need to use a uni foam filter, only k&n pods are good for deserts

It is safe if you know how to ride with it. You cant go trough water, hitting puddles isnt recommended...

Heres mine

 

[blasterdemon7]

It's best to keep it in the Air box. It won't run right with it mounted direct to the carb. You will have to add a length of pipe to move it back.

 

[Herpderplol]

It's best to keep it in the Air box. It won't run right with it mounted direct to the carb. You will have to add a length of pipe to move it back.

Yes true, i have a 3-4 inch pipe

Just another connection to leak at....

 

[foxracingkid22]

thanks for the help guys. i was just wondering because the intake hose on mine the goes to the box has a tear where it goes over the carb. and i was seeing about that cause that would be a cheaper route

 

[Blaaster]

It fine to run the filter directly on the carby throat, it is about the best breathing that you will ever get but you must jet for it, and confirm by a plug chop.

The filter has to a foam one as fuel will spit back and wet it, so paper types will not be suitable.

from Gordon Jennings 2 stroke Guru.......Maximum air flow will be obtained with the carburetor crowded close to the port window, and an extension on the carburetor’s inlet to provide the correct tract length, but that arrangement also gives the worst conditions for mixture delivery. Positioning the carburetor at the intake tract’s outer end reduces volumetric efficiency somewhat, but provides the best mixture-strength stability. Connections to the air cleaner should be as short as possible, but if it is necessary to separate the carburetor and air cleaner by more than a couple of inches, the passage linking them should be either a cone (diverging at least 15-degrees) or a parallel-wall tube having about 400-percent of the throttle bore’s cross-sectional area. Both of these will provide essentially the same condition as a pure, atmospheric inlet, and prevent secondary resonances that also can upset fuel metering.

Gordon Jennings Two-Stroke Tuner's Handbook | Two Stroke Engine Tuning

 

[blasterdemon7]

It fine to run the filter directly on the carby throat, it is about the best breathing that you will ever get but you must jet for it, and confirm by a plug chop.

The filter has to a foam one as fuel will spit back and wet it, so paper types will not be suitable.

It seems a lot of members have bad problem running direct on the carb. It seems to screw up the air flow to the point that the jets don't flow correctly . I haven't run one like that myself but have read some thread of the problem.

 

[Blaaster]

Then I must be some special type of guy, I have run my filter directly on my carb for the last 55 years and never have not been able to sort out a jetting problem.

Most of the problems with jetting that I experience is from people running a carby way too big for the application.

A carby too big for its application is always going to be a challenge to jet.

Large carbys are great for top end but can be very difficult to jet lower in the rev range.