Chengine stock air filter housing mounting screw size?

[Pablo]

I'm not at home right now and need to know the chengine stock air filter housing mounting screw size. Are those two screws 4mm or 5mm? (they are in the carb intake face)

I'm finally getting back to finishing up the air filter project. On the prototype I opened the threaded carb hole up and retapped to a larger SAE size because I didn't have long enough metric screws.

The plan is to use an Amsoil EaA breather filter for HT engines, but they don't have the ability to clamp onto the little carburetor lip circumferentially. So the long metric screws will be used to pull and seal the outer mounting face against the carb intake face. I will have a fat hooded version and a lower clearance version. Either will filter and flow better and look much nicer than stock.

Obviously with a stock carb I want to stay with the stock screw size and not require people to drill and tap on their carbs! Hence my need for the screw size

 

[wildemere]

Stock HT carb is M4

 

[Pablo]

Thanks! I would have guessed that....but needed someone to check. I can grab some on the way home.

 

[Bronzebird]

Hey Pablo, I hope to see the performance increases from the enhanced airbox. Very good idea in my opinion. I'll go a step further and put my idea out...ram air scoop that wraps around left and right side of frame. And even mount dual battery opperated headlights underneath the scoop to shine closer to the road or trail!
100% positive air flow!! It may look big to be effective at 20mph-30mph. Add expanision pipes and I like the mental picture...

 

[Pablo]

Ram air scoop! At 30-40 mph??

My reasoning is two fold, anything other than NO air filter must filter better than the supplied "mesh", oil or no. So it's just a matter of flow (or not impeding flow) via the correct media and size.

Here's my proto:

 

[Bronzebird]

Great looking filter

Ram air scoop! At 30-40 mph??

My reasoning is two fold, anything other than NO air filter must filter better than the supplied "mesh", oil or no. So it's just a matter of flow (or not impeding flow) via the correct media and size.

Here's my proto:

Very nice improvement! Hey I noticed the clutch cable brass stopper does not appear to have any solder at end of stop. I got some flux core small diameter solder and sealed the butt to reduce chance of slippage incase the screws does not hold. Rational: Do not have to crank on the torq and damage cable threads with the metal screw clampage.

 

[Pablo]

Your clutch pull must be nasty. Mine has never had an urge to slip. That's my old crappy cable in that picture. Long gone.