Vintage Dirt Bike Q & A

I went and rebuilt the front forks on my 80 CR250 today, yay for 30 year old crud, had to cut and pry the old seals out. Anyway I was able to get the right fork cap off but the left wouldn't move and I don't think I am the first person to try as the cap was all chewed up. So instead I was wondering if I could use a large syringe and some tubing to fill that fork with oil through the threaded hold that the air fitting goes in, I know it will be slow but I don't want to molest the cap any more. I don't see why it wont work but I just wanted to make sure there wasn't any reason I shouldn't.

You shouldn't because it's not really the right way... Plus, you'll never get ALL the crud out of your forks if you don't take the top bolt out.

Unfortunately, it's a discontinued part, but I'm sure you can take the one you have out to a motorcycle shop or a machine shop and they'll be able to tell you the specs on it... that way you can potentially find a fork cap from another bike that will fit yours.

I'm 99.99% sure they're a 38mm fork... so...

http://billetparts.co.uk/catalog/produc ... ucts_id=58

I don't know what the pitch and size of the stock thread is... so that's something you need to find out.

Other than that... you need to remove the caps and empty out the forks of the springs, damper rod, etc... and let them hang upside-down for about 12 hours to FULLY get all the gunk out. Then you can worry about a refill.

You don't "NEED" vented caps on that bike either. I suppose it's good for on-the-fly adjustment, but they're not a pressurized shock... they are simply a neutrally-buoyant system, so it's not a necessity.

For removing the other leg's bolt, you've got to re-install them in the triple clams, get a good sized pipe-wrench and stiffly give it a jarring to try and break it loose. Might help to have a buddy hold the bike. Otherwise, bench-vise... pipe wrench.

You may have to elevate the situation to vise-grips and a hammer... but that all depends on how goosed the PO made it for you.

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I drink your milkshake!

and 100% wrong , 37mm is right.
tread is M32x1.5.

@ohm, if you don´t take the fork legs apart into all pieces you won´t get rid of all that dirt, slime etc. that´s in your fork now. you have to clean all internal parts. only new seals and oil is not rebuilding, it´s shit.

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80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

Wow, those are some kind words, good thing I have never rebuilt a fork before and didn't know to clean anything before putting it back together and that the black slim that used to be ATF wasn't good for the fork. I supposed if I wanted I could custom make a replica fork cap, everyone should have a lathe and milling machine in their garage, and just cut the old cap off, or I can just fill it through the air inlet and be done.

Really? Are you going by the seal size or the actual fork? Because I thought the ID of the seals runs smaller than the OD of the fork?

Meh, oh well.

Dude, ohm. You wanted a straight up answer, and NO is it. Must take apart. There is no way you will even accurately fill the fork back up to the proper level without removing the cap. Just take it off with a set of vise grips and re-install the same way. It's busted regardless if you take it off or leave it on. Might as well try.

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I drink your milkshake!

sorry for these hard words but it´s the truth.
may get some caps here. http://www.hondapartshouse.com/honda-parts.aspx?aribrand=HOM#/Honda/CR250R_A_%2880%29_MOTORCYCLE%2c_JPN%2c_VIN%23_ME03-2001031_TO_ME03-2016050/FRONT_FORK_80
90123-467-672 BOLT, FR. FORK $33.42

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80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

Those should work... if by chance they have them.

_________________
I drink your milkshake!

If the cap size and thread is common between the 78, 79 and 80 forks I have a set of after-market air caps that might fit the bill...

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Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF

I was able to get the cap off the left fork, had to put it in the mill vise and use a strap wrench but it came off. Got it filled "Properly" and put everything back together.

I find that dumping some solvent in the fork leg with your finger over the bolt hole on the bottom and the gently shaking it a bit gets most all of the gunk out.