Small or Large Velocity Ring K&N Filter or revert to stock air filter ?

[Sentinal]

Hi all its been a long time, God how I have missed you...

I have searched the forums and I am unable to find the answer to my quest.

A while back I had my bike dyno'd by a guy who did not have a lot of experience, he jetted my bike, Factory Pro with 106 jets mikuni (main jet) and the small velocity ring, as I left the dyno the bike surged like hell, (the dyno room was really hot), He replaced the mains back to Stock 110's mikuni mains and the bike ran fine.

After much deliberation with myself and recalling the events of the day and a lot of reading of the instructions from Factory Pro, K&N, Dynojet, I came to the conclusion that the guy did not know what he was doing.

When the large ring was fitted he tried various jets and could not get the bottom end dialled in, it was too rich, low RPM not sure if this was WOT or not, so I do not know why he stayed with the small ring??


My bike is UK spec 600cc 1995 katana, 5° ignition advance, K&N, full micron race system, it was Dyno'd with 110 mikuni mains as standard. With small velocity ring fitted, needles 3rd, float level 14.6,new emulsion tubes (suzuki)

I have fitted 117.5 mikuni mains and the large velocity ring as I feel / understand that if I can get more air/fuel mixture then this will increase speed - (I tried the large ring with 110 mikuni mains I got masses of lean surging so much so it was like riding a bronco hence why I upped the size

Does anyone know the size change of main jets between the two velocity ring sizes as I am unsure as to if I have gone too large, and some people I have spoken to think that 117.5 mikuni mains might be a bit too large a main for a 600 and I do not want to pay out any more money for dyno time as there is no one I trust in this area (near Leeds UK)

OR

Do I bin the K&N go back to stock 110 mains mikuni and stock air filter ?

Below is some of the reference stuff I found~~



K&N filter #SU7592 instructions,
Install the appropriate velocity ring.
Small diameter velocity ring: To be used on a stock motorcycle.
Large diameter velocity ring: To be used for increased air flow on a motorcycle that has a carburettor recalibration kit installed.

Dynojet instructions,
1. If you are running a K&N stock replacement air filter you will need to use a main jet that is 10 points larger. If you are using the DJ106 main jets you will need to install the DJ116 main jets. If you are using the DJ110 you will need to install the DJ120 main jet.

http://www.kandn.com/instructions/SU-7592.pdf

http://www.dynojet.com/pdf/3131.pdf

[arsenic]

I'd say take the easy road and go with the oem filter. You had it dyno tuned and the K&N still doesn't work right, that says something.

[loudnlow7484]

Personally, I think it's possible to make anything work. But it might not be worth the time, effort, hassle, and money involved.

More importantly, though...... What did it dyno at? (hp)

[Sentinal]

Personally, I think it's possible to make anything work. But it might not be worth the time, effort, hassle, and money involved.

More importantly, though...... What did it dyno at? (hp)

This was before the Dyno chap had to re-jet due to putting too small a jet in- read above,
this is on a real hot day in England, about 28° C ambient temp and in a dyno room with no cooling, yes I know,

UK 600 FS 1995 Spec bike, Fitted Items, Factory Pro 5° advance, K&N small ring, Full micron can, ms 2 1/4 out,factory pro jet kit, 106 mikuni mains , its says Needles 2 but I was sure these are set to 3, I need to lift my tank again to confirm this, Oh joy I have just refuel'd


ECECOR .988

cwhlpw CHp 74.7 ECEpwr HP 85.2 ECETrq lb-ft 40.3 AF13.1 @ 11093 rpm
cwhlpw CHp 59.9 ECEpwr HP 67.2 ECETrq lb-ft 42.1 AF12.5 @ 18386 rpm

Dyno picture is here, it was june 2005

http://www.sentinal.eclipse.co.uk/style/