Cut air filter, loss of power.

[Dave Mac]

i have cut the centre out of my air filter (the hard plastic bit) and i have raised the front of the tank by about 3 mm.

however when i hit about 7000 revs im getting a loss of power. it still has the padding on the tank. i thought about removing it but it is stuck in fast and not loose so i cant see that being the problem especially as it didnt do it before i changed the filter

any ideas?
i am thinking of putting the old one back on now
its a 2002 curvy

cheers dave

[jambo]

To clarify: You have a curvy (2002) SV650 and have widened the plastic entry hole in the centre of the air filter to make it more free flowing?

If this is the case, put the old one back in and see how you go. My suspicion is that the mixture may become leaner at high RPM as the carbs are not suited to the non-standard filter.

If the problem goes away with the old filter fitted you have your answer ;)

Jambo

[Dave Mac]

cheers i had a feeling that might be it, thought i would post and see.

the extra 3 mil clearance at the front of the tank shouldnt matter should it?

[jambo]

cheers i had a feeling that might be it, thought i would post and see.

the extra 3 mil clearance at the front of the tank shouldnt matter should it?
If in doubt, put everything back to standard and start from a known good place. However, of the two modifications, this should be the least significant.

Jambo

[Dave Mac]

cheers, im going to put the old filter in and give it a bash with the extra 3 mil clearance, if it still struggles ill keep the old filter and remove the 3 mil

many thanks

[yorkie_chris]

I'd say with a fair degree of confidence that it's running as lean as a starving crackhead through iceland.

[demonicus]

my fault! i gave him the filter to cut up as i put a k&n in mine.

[yorkie_chris]

can run alright like that, but you need to rejet.

[demonicus]

i recall something you said about 5 quids worth of mikuni jets would sort the problem, is that correct? what size did you mention?

[demonicus]

he just wants to be able to keep up with me!

[yorkie_chris]

i recall something you said about 5 quids worth of mikuni jets would sort the problem, is that correct? what size did you mention?

Probably about 150>155

But it is a lot of messing for not a lot of power. Personally I would not rejet or change filter for a performance one unless I already had a full system to go on.

[demonicus]

fair point.

[yorkie_chris]

cheapest mod you can do around that area for not much money is fit more intake cams on exhaust side.

[demonicus]

que? is this the pointy cam mod i have read on here at some point in the past

[yorkie_chris]

Half of cam swap aye, pointy cam swap is a bit better but more money.

[demonicus]

wish you lived in the midlands matey, would supply you with hob nobs and beer for your expertise!

[Dave Mac]

i can keep up with you, i just have to get used to the v twin after the inline 4.

its all back to standard and working normally now


many thanks for the advice

[demonicus]

arent you supposed to be polishing your gun or something dave! lol

[Dave Mac]

even us squaddies are allowed a lunch break adam