how do you change the front fork seal ?

[Valentino Mossy]

hi all, i've just bought an old nsr125 on a j plate ,and the fork seals need replacing .any ideas ? - i have not bought a manual for it yet, done all the easy stuff on the bike ..... 1st bike !.... thanks

[Robby]

Ok. Big description. Please read everything before doing anything.

You need to jack the front end up, get the front wheel and mudguard off, loosen the various bolts in the yokes to drop the forks out.

Then individually open the fork tops, drain out the oil, then put the tops back on. You need to undo the damper rod bolt, which I have never done on an NSR, but with the VFR forks I had to compress the fork by clamping the brake caliper mounting lugs in a vice and using a car jack to compress the fork. I could then undo the damper rod bolt with an allen key - I think it was 10mm, but it was a size that doesn't come in a normal little socket set.

right, with the damper rod undone you take out the damper rod bolt and undo the fork top again, this time taking out the spacer and spring, and draining any more oil if there is any left.

Now prise up the dust cap and prise the snap ring out of its groove under it. Take them off and put them somewhere safe.

Then you push the fork slider in slowly and pull it out hard - do this a few times and the 2 pieces will come apart.

You have now stripped your forks.

Next bit is easy. Just pull off the old fork seal, clean the fork around where it used to live and make sure the surface is smooth and clean.

Now you need to get the bushes back in place. Push the slider back into the fork leg, and you'll find a copper bush sitting on top of a hole. Persuade it in there - I usually squeeze it just into the space by hand, then knock it in with a screwdriver and mallet very slowly.

Take the new fork seal and lube it up a bit with fresh fork oil. Gently slide it down the fork leg, not forgetting the washer which goes between the bush and the seal. If you are using leakproof fork seals you now need to fit another washer, and then reinstall the snap ring - make double sure the snap ring is seated into its groove all round. Push the dust cap back on.

Pop the spring and spacer back in, put the fork top on, and compress the fork as before to do up the damper rod bolt. When this is done up, take the top off again and take out the spring and space. Fill the fork with the correct amount of fork oil in your chosen weight - probably about 10 or 15 weight. With this in the fork push the slider in and out slowly at least 10 times. You may hear some bubbling if you listen carefully, this is just getting the oil properly distributed around the fork.

Put the spring and spacer back in slowly, not forgetting the washer that goes between them - it may have fallen into your oil drain can if you weren't careful, i always end up dropping it in there. Put the fork top back on. One fork is now complete.

Do the same with the other fork.

Now reinstall the forks into the yokes, then put on the mudguard and finally the wheel. Check all the bolts are done up good and tight, and take it out for a gentle test ride.

A note on undoing the damper rod bolt - there is probably a Honda tool for it, so you don't need to compress the forks to do it, which is quite hard. Alternatively take a broom handle and knock it into the end of the forks to get an impression of the bolt down there, and carve it back a bit more so you have a homemade socket for NSR forks.

[Kickstart]

Hi

Just to add to that, the damper rod is on the bottom of the fork. If you start to undo it before you have taken the spring out the spring tension will hold it steady.

All the best

Keith
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[Valentino Mossy]

thanks for all of that, im going to try and replace them tomorrow when i come home from work---- ps.. does anybody know how to get it to "kick start" quicker, it takes me about 10 min( starting and stoping)- unless the battery a bit flat !

my brother-in-law said you can get a kit which will change it from a kick start to an electric start, is this true or is he pulling my plonker !


thanks from lilldic_mossy ( whose trying to get this old shed of a bike back on the road ) !

[Kickstart]

Hi

NSR125 models with a kickstart are quite rare. I have only ever seen one (although all the NS125R models were kick start only).

Try kick starting it without holding the throttle. Tends to happen that as you kick it you open the throttle which rarely helps.

If it starts then dies check the choke is working

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Valentino Mossy]

Right now im totally confused !,, when i bought the bike of a mate he told me it was a honda nsr125, BUT ,looking at some photos on the web its either ns125r or nsr125 !

are there 2 types of bikes or is just different names for the same ?, if so what are the main difference and which are better ?

mines got a kick start, square lights, two wheels, etc.......

[Valentino Mossy]

plus the decals on the side says nsr !

[Kickstart]

Hi

It sounds like it is an NS125. These were sold from about 1985 I think, and the NSR125 replaced them (although in the UK they were sold side by side for a while).

The NS125 was available as an F model with a bikini fairing and an R model with a full fairing.

The later NSR is the better bike. Better brakes, better handling. The NS has a steel frame, the NSR an alloy frame.

It should kick start quite easily

All the best

Keith
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