Oval Carb Air filter question

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Hey guys!

So I have a set of Triumph 900 Mikuni SS carbs that I will fit on my new XS 750 project.

The intake side of the carb mouths are oval and I want to fit K+N airfilters to them.Is there a way to mount the K+N good and sealing?
Is it possible to measure the longer "distance" of the oval opening and take this size for the K+N filter?

Has anyone fitted a K+N to an oval carb mouth?

Thanks in advance!
 

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They dont look oval enough to be impossible to fit.. take the long measurement, and the short, and use filters somewhere between the two in size? They do flex, so 1mm here and there will be taken up.
 
Those carbs look right odd with that spray tube going in the middle of it by the way. Not a very common design?
 
datadavid said:
Those carbs look right odd with that spray tube going in the middle of it by the way. Not a very common design?

I think he has removed the main jet and has pushed the needle jet almost all the way out. They are not like that when assembled.
 
Hey peeps!

Thanks for chiming in!
These are pics from a website where the carbs are completely dissassembled, so no nitrous in there ;D

As for the air filter: I measured 64MM on the long and 58 on the short distance of the carb mouth.My guess was taking a 64MM K+N filter and then with tightening the clip around the flange the 6MM should be "equalised"?..?

David didn´t you use Oval Keihins on youre XS build (with pods)?
 
Ryan Stecken said:
Hey peeps!

Thanks for chiming in!
These are pics from a website where the carbs are completely dissassembled, so no nitrous in there ;D

As for the air filter: I measured 64MM on the long and 58 on the short distance of the carb mouth.My guess was taking a 64MM K+N filter and then with tightening the clip around the flange the 6MM should be "equalised"?..?

David didn´t you use Oval Keihins on youre XS build (with pods)?

Nope they were round, 54mm i think. I would go for slightly smaller, maybe 62 mm. Would prefer to slightly stretch than compress, but i may be wrong!
 
If they're really that long, you could order 63mm mushroom filters from Kickstarter-Shop in Germany (that's where I bought mine for the VM carbs).
 
I'd measure around the oval, then convert that circumference to the equivalent diameter for a circular filter.

Eg measure round the carb oval opening with a piece of string = eg 200mm
Equivalent round filter = 200/PI = roughly 64mm diameter

Steve
 
Sderbyshire said:
I'd measure around the oval, then convert that circumference to the equivalent diameter for a circular filter.

Eg measure round the carb oval opening with a piece of string = eg 200mm
Equivalent round filter = 200/PI = roughly 64mm diameter

Steve

^science.


Yes man thanks!Exactly how I did it.Took a paper string and measured the length...boom..6,12cm Diameter.

Thanks for the help!
 
As yours will take a little longer to build than my XS, you can have my filters. I only need them, when I present the bike to the department of motor vehicles to have "non-stock aircleaner" in the papers, as I'll build a proper performance one later. (But my waterjet-cutting place is closed at the moment!)
 
der_nanno said:
As yours will take a little longer to build than my XS, you can have my filters. I only need them, when I present the bike to the department of motor vehicles to have "non-stock aircleaner" in the papers, as I'll build a proper performance one later. (But my waterjet-cutting place is closed at the moment!)

Thanks nanno!

I know this is a can of worms but is there a a preferable shape to a pod filter? I mean oval or straight, does it make a difference?
 
Theoretically an oval one will have more surface area, resulting in more flow. Truth is, at best we're talking single digit percent point differences... If you want performance, you're better off with a set of velocity stacks and then build an airbox around it (which is pretty much my plan.)
 
Correct me if I am wrong, looking at the photo the actual air intake is round. The vacuum port at the top of the intake has been added to the top and blended into the profile to create the oval shape. The original Mikunis have a round outer shape and the vacuum port cuts into the inlet area to actually reduce the inlet area.

Sent from my SM-G900I using DO THE TON mobile app
 
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