K&N aair filters

Post by **FrankM83** » Sat Mar 21, 2009 11:25 pm

HI all excuse my stupidity but can anyone point me in the right direction for a good K&N air filter preferably off Ebay!? as I don't want to buy the wrong type again! I have an HS4 carb Thanks

Post by **toginthemog** » Sat Mar 21, 2009 11:30 pm

frank k&n are good and look good and I bet malta is warmer than here but this filter is what I am getting carb iceing up from I got mine new from demon tweeks but like all ebay items you have to spot it at the right time will keep my eye out for s/hand one

Post by **d_harris** » Sun Mar 22, 2009 12:11 am

I'm guessting you mean an HS4 rather than a HS$ as opposed to some weird currency?

Post by **FrankM83** » Sun Mar 22, 2009 12:20 am

ooppss edited!

Post by **Longdog** » Sun Mar 22, 2009 6:37 am

Hi Frank, correct K & N part number for HS4 carb is 56-9320, there is one for about £37. on ebay currently but they do come up for less.You may need to change the needle in conjunction with filter though as it weakens the mixture due to better air flow.

Post by **Kevin** » Sun Mar 22, 2009 7:54 am

Frank if you are insure you can always ask for a photo of the mounting side to be sure its correct, what did you buy a mini one with the offset.

Post by **FrankM83** » Sun Mar 22, 2009 6:53 pm

I bought a pancake type!

where can I get a correct needle pls?

Post by **bmcecosse** » Sun Mar 22, 2009 7:26 pm

Hope you didn't buy a 'pancake' - because they are not very efficient to put it mildly. The flat face of the filter must be AT LEAST 1.5 X the diameter of the carb inlet away from the carb inlet face. Most 'pancakes' are far too near and seriously disrupt the air flow at full chat.
With any change to the engine - you may or may not need a different needle in the SU. There is no set rule on this - sometimes a change of oil in the damper will correct the mixture sufficiently. Fitting a 'more efficient' filter will allow more air into the engine -at or close to full revs - it makes absolutely no difference at lower revs because the original filter was (presumably) perfectly capable of pasing enough air at the lower revs. The engine only needs so much air to develop the power required - this is what you adjust with the accelerator pedal. Ideally the engine would need setting up on a rolling road - a timeconsuming (if done properly) and therefore v expensive operation! What spec is your engine - and in particular what carb is on the engine ?