TJ91 Posted February 10, 2011 Report Share Posted February 10, 2011 (edited) so i decided to pull the bike out of the barn and try get it going this morning, ages since i moved and had totaly forgot the fork problem. i push down on the handlebars with half my weight and the forks bottom out...obviously would be very dangerous to ride as is. i lifted the front of the bike up so there was no weight on the forks and unscrewed the nuts on top of the fork stanchions to find there was no spacer on top of the forks!? am i right in thinking there should always be a plastic or metal tube spacer on top of the springs? Would putting a tube spacer (of a specific length) on the springs compress the fork springs so that they are stiffer and dont bottom out so easily? Edited February 10, 2011 by TJ91 Quote Link to comment Share on other sites More sharing options...
southeastpete Posted February 10, 2011 Report Share Posted February 10, 2011 do they have any liquid in? have you checked the fork seals? Quote Link to comment Share on other sites More sharing options...
TJ91 Posted February 10, 2011 Author Report Share Posted February 10, 2011 do they have any liquid in? have you checked the fork seals? Oil and seals are all fine. fork oil only changes the rate it moves at, not how far it moves its definatly the springs..either the springs for some reason have lost compression :blink: or like i said they should have a spacer...all other bikes i have owned have always had spacers on top of the springs..but this one doesnt. i can only assume someone has been in and put either the wrong springs in or not put tube spacers back in when reassembling. i have never rode the bike, bought it to do it up for the summer, it was like this when i bought it. Quote Link to comment Share on other sites More sharing options...
willcsmith Posted February 10, 2011 Report Share Posted February 10, 2011 What bike? Quote Link to comment Share on other sites More sharing options...
TJ91 Posted February 10, 2011 Author Report Share Posted February 10, 2011 fzr400 Quote Link to comment Share on other sites More sharing options...
foxbuster Posted February 10, 2011 Report Share Posted February 10, 2011 Sounds to me like lack of oil too. Have you had this problem since you've had the bike?? Take it theres no compression damping or rebound adjustments on the fzr?? If your oil has pee'd out over the years you'll have no damping to aid the spring. Think you should also have damping rings at the bottom of the spring-are they still there?? Quote Link to comment Share on other sites More sharing options...
TJ91 Posted February 10, 2011 Author Report Share Posted February 10, 2011 it was like this when i got it..have never really rode it, bought as project and am finally egtting around to doing it now. everything is there as it should be, oil (correct ammount), rings, spring. no they never put adjusters on these. the only way of adjusting is putting spacers in and different oil. recommened oil is 10w and i have 15w in it. if i compress the spring with a spacer will it stiffen the suspension up? i could go down the route of new hagon progressive springs and put cartridges in but i dont realy want to put to much money into it Quote Link to comment Share on other sites More sharing options...
foxbuster Posted February 10, 2011 Report Share Posted February 10, 2011 it was like this when i got it..have never really rode it, bought as project and am finally egtting around to doing it now. everything is there as it should be, oil (correct ammount), rings, spring. no they never put adjusters on these. the only way of adjusting is putting spacers in and different oil. recommened oil is 10w and i have 15w in it. if i compress the spring with a spacer will it stiffen the suspension up? i could go down the route of new hagon progressive springs and put cartridges in but i dont realy want to put to much money into it Dont think a spacer will stiffen it up mate-will just bottom out sooner. Think you may have to go down that route of new springs and get them checked properly-you dont want to mess with around with them if your not sure, pretty important part of the bike-keeps the wheel on the road!! Quote Link to comment Share on other sites More sharing options...
100milesaway Posted February 10, 2011 Report Share Posted February 10, 2011 Suggest you get hold of a Haynes manual or a genuine Yamaha fzr 400 manual, off fleabay, not sure if they imported that model into the UK so you may struggle to get one. The blow up diagrams will reveal all. from Auntie. Quote Link to comment Share on other sites More sharing options...
Cookiemonsterandmerlin. Posted February 10, 2011 Report Share Posted February 10, 2011 What I guess is that the fork oil has gone and the springs have rusted in situ. Take them and send them away for proper repair . Cheers OTH Quote Link to comment Share on other sites More sharing options...
chippy18 Posted February 10, 2011 Report Share Posted February 10, 2011 (edited) The standard suspension on the 400's was absolutely rubbish anyway. You should have a spacer in the spring tube. The size of the spacer depends on rate of preload that is recommended for the forks. When i had one i added stiffer springs and you could also fit a valve emulator which totally changes the suspension. You can get a rough length for the spacer if you take a measurement from the top of the fork tube to the top of the washer that sits on the spring, then measure the tube cap from the bottom where the spacer will touch, to the bottom of sealing lip. then subtract the the 2nd measurement from the first which will give you the length of the spacer without any preload. All you do then is add whatever preload you want or the recommended for your springs, weight etc and that is your spacer length. Make sure that when you put it all together that as well as a washer on top of the spring that you put a washer on top of the spacer. There used to be a firm called Tech 1 racing that we used to get all our after market parts from and you could work out the preload by putting in your weight. riding style and a few other bits of information, but i expect they are not around anymore. Another good outfit was RaceTech. Cheers Edited February 10, 2011 by chippy18 Quote Link to comment Share on other sites More sharing options...
rob4586 Posted February 11, 2011 Report Share Posted February 11, 2011 (edited) Oil and seals are all fine. fork oil only changes the rate it moves at, not how far it moves The oil is a dampening fluid and will also reduce compression of the spring. Remember, oil is virtually incompressible. I'd strip the forks down completely and check the state of them, as mentioned they may of rusted in situ. Either new springs or send away for overhaul. Rob Edited February 11, 2011 by rob4586 Quote Link to comment Share on other sites More sharing options...
willcsmith Posted February 11, 2011 Report Share Posted February 11, 2011 You should have above the damper rod your spring a washer and a 135mm spacer Quote Link to comment Share on other sites More sharing options...
Andy 01 Posted February 11, 2011 Report Share Posted February 11, 2011 This may be of use http://www.manualedereparatie.info/en/categorii/yamaha.html Quote Link to comment Share on other sites More sharing options...
TJ91 Posted February 11, 2011 Author Report Share Posted February 11, 2011 springs are not corroded, they come out easy as pie and look in good nik there is the correct amount of oil, it is 15w and not very old (no water or gunk in it) Quote Link to comment Share on other sites More sharing options...
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