How much fork oil??

There seems to be more and more members appearing that are racing the ZXR400 so i've created a special section just for you to show off results, discuss meets etc etc.

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keith_eire
Posts: 16
Joined: Fri Sep 24, 2010 2:36 pm
My Bike: K4 GSXR600, ZXR 400L

How much fork oil??

Post by keith_eire »

Hi lads, I just replaced the fork seals on the race bike and put some new fork oil in one of the legs but it seems a bit too hard so am thinkin I've put too much oil in (464ml). The forks have k Tec 85lb springs in them so would anyone know how much oil should be put in with those? Thanks lads.
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mick41zxr
zxr400 oc member
zxr400 oc member
Posts: 170
Joined: Wed Jan 14, 2009 4:07 am
My Bike: ZXR400sp

Re: How much fork oil??

Post by mick41zxr »

Fork oil is usually measured in air gap, usually in a range of 90-120mm, both legs the same. Height is part of your set up.
Regards,
MB
keith_eire
Posts: 16
Joined: Fri Sep 24, 2010 2:36 pm
My Bike: K4 GSXR600, ZXR 400L

Re: How much fork oil??

Post by keith_eire »

Thanks Mick, I've obviously used way too much oil but I think maybe the oil is too heavy also. I got it off a guy in a local bike shop and told him it was for a race bike so he said the stuff he gave me was medium? Any idea what grade oil I should be using?
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mick41zxr
zxr400 oc member
zxr400 oc member
Posts: 170
Joined: Wed Jan 14, 2009 4:07 am
My Bike: ZXR400sp

Re: How much fork oil??

Post by mick41zxr »

It really depends on the fork set up, 5 to 10 wt is common however you need to know how the fork has been set. If you dont know what valving & spring you are running I suggest a visit to a suspension tech.
Regards,
MB
keith_eire
Posts: 16
Joined: Fri Sep 24, 2010 2:36 pm
My Bike: K4 GSXR600, ZXR 400L

Re: How much fork oil??

Post by keith_eire »

Thanks again Mick, thought I'd be able to sort them myself but looks like I'll just have to take them to an expert like you said :smt017
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mick41zxr
zxr400 oc member
zxr400 oc member
Posts: 170
Joined: Wed Jan 14, 2009 4:07 am
My Bike: ZXR400sp

Re: How much fork oil??

Post by mick41zxr »

Look you may be ok, but once the fork is done a good tech will give you a build sheet with oil height & weight setting for you to do, you should get a log of everything. Fork oil fouls quickly I do mine twice a season.
Regards,
MB
cargo
zxr400 oc member
zxr400 oc member
Posts: 3342
Joined: Sat Jan 08, 2005 10:33 am
My Bike: tomos moped
Location: Carrickfergus Northern Ireland

Re: How much fork oil??

Post by cargo »

I never touch the damn things................only one man in Ireland for that job


Clarance Bell................... PLR Suspension
keith_eire
Posts: 16
Joined: Fri Sep 24, 2010 2:36 pm
My Bike: K4 GSXR600, ZXR 400L

Re: How much fork oil??

Post by keith_eire »

Yeah I spoke to Clarance up at the Motorcycle and Scooter show in Kingshall lat feb I think it was, he serviced my white power shock for me. I have his card somewhere I'll get him to set them up for me for next year! For now it apears the dampers in the fork's were gone, we stripped them down and replaced them and they seem much better now with 120mm of 5wt oil. They'll get me through the last tract day on Sunday and then I'll get them serviced by Clarance, thanks for the advice lads
Max4music
Posts: 132
Joined: Tue Aug 26, 2008 8:29 pm
My Bike: zx7r / zxr400

Re: How much fork oil??

Post by Max4music »

If its of any help, Ive got K-tech reworked forks with with 8.5 springs. K-teck recommended 5wt oil with a 140mm airgap.

Hope you got it sorted.

Max
keith_eire
Posts: 16
Joined: Fri Sep 24, 2010 2:36 pm
My Bike: K4 GSXR600, ZXR 400L

Re: How much fork oil??

Post by keith_eire »

Yeah got sorted thanks, after stripping them down twice we discovered the dampers in both forks were seezed....replaced them and now all is perfect. Was told the bike had been stood for over a year before I got my hands on it so am in the process of giving everything a good going over, thanks again for the reply's
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