XJ650 82 front forks

So I'm rebuilding my xj650 and I want to lower the front with the cutting spring/add spacer method, but my fork has an air valve at the top. When I just unscrew the valve it's just a hole in there.. And I saw a diagram that there might be a circlip but really I can't see anything in there and I don't know how to dissemble this thing up. Her are some pictures...

 

You have to push down/compress that thing which the air valve was removed to get access to that circlip.

 

I did, but i didnt knew how far since the fork was compressing as its natural movement.. guess ill have to compress it a little more... Ill see whats up in a few hours. Thanks!

 

You don't compress the fork - you press the cap down in the inner tube. About 1/8" is all it takes.

 

If pressing on the plug is causing the fork to compress that points to the plug being corroded in place. Soak it with penetrating oil and wait overnight. Try again. Repeat as needed until it's unstuck (use a hardwood dowel and a hammer on the plug. Give it a good rap to help break up the corrosion). While you're waiting on the oil to do it's job you can take a small file and dress the inside of the top of the fork tube where someone dempled it with a hammer. The inner bore has to be smooth or the plug won't come out.

 

im doing this today cause i guess its stuck... after this can i buy a cap bolts instead of this air valve cap things?

 

It aint working you guys.. its stuck, makes me think that if i get it out somehow, when i re install it, is going to be a problem too..

so im thinking of a front end swap... maybe an R1 front end.

 

I had this problem a few months ago. No air valve in top of my plugs though. (I had to drill and 'tap' a thread into the top of my plug)
If your plug has a 'thread' running through it for the valve, then you can try using a 'hammer slide', and adapt the end of the hammer slide rod, so it is the same as the thread in the plug? Screw in the hammer slide (after soaking plug in top of fork at least over night in freeing oil, then use slide as directed, pulling upwards (basically using a 'reverse' hammer action). This should remove it, and you won't be damaging your internal thread for your air valve.
If this does not work, then adapt an extractor tool by fabricating a rectangular steel/alloy plate that sits across the diameter of the top of the tube, drill a hole in the plate the diameter of the hole in the plug underneath in the tube, insert an exact thread copy of the diameter of the valve hole (about 5-6cm long)hex bolt through the hole in the plate, and screw into the hole clockwise......do this slowly, bit-by-bit, and the plug should pop out
Hope this helps

 

You MUST push the plug in a bit first to remove the circlip.

 

You gotta get the fork in a vice, using something to protect the metal (I used a couple erasers), grab a deep impact socket, and push hard on the cap. Be sure to clamp it in the vice well below where the cap and circlip are. Remember, there is a lot of pressure behind there because of the spring, so get a buddy to help... one of you pushes and holds the cap down, the other gets in there with a micro flathead screwdriver and pries the circlip out.

I managed to get 1 on my own (after a 45min struggle), but the other one was so corroded it got stuck down, so I had to tap it and pull it out.

 

Can you get hold of a spare triple tree? The lower one is steel. 8)

Clamp it on and use a pulley remover or something like it to compress the cup.

A fancy version would be a weldment with plenty of clearance to get to the circlip. I could whip one up in a half hr in my toolroom.

 

Freeing up the corrosion will take more than just a day. Let the penetrating oil work for a week. Patience pays.

 

If you put the fork in a vise I have a couple suggestions:

1) Cut a piece from an old inner tube to slide over the tube for protection.

2) Clamp the tube in the region above where the lower tree clamps it. That way if you nick the finish it'll be in an area where the oil seal doesn't run.

I like to get the caps loose while the fork is still on the motorcycle. Loosen the upper clamps then give caps a few sharp raps with a hammer and punch to break them loose.

Then I pull the fork and put it in a long bar clamp with a deep socket pressing into the cap end. You need to clamp to be have about 1" gap so you can back it up to release the spring pressure.

Tighten the clamp until the cap moves down 1/8" or the fork compresses 1/8". Usually the fork will compress, but if you got the cap broke loose you should be able to push the inner tube toward the socket to expose the retaining wire.

Dig the wire out.

Open the clamp to unload the spring.

If you have a helper have him push the cap down while the fork is still clamped in the lower tree while you dig the retaining ring out. Then have him carefully release the spring tension.

 

Use penetrating oil as suggested. Rap on caps to help break them loose as suggested. Go to home improvement store and buy a furniture clamp long enough to reach the bottom of the forks. Once the caps are loose only compress them 1/8" and remove the circlips. The fork innerds get more narrow the more you compress.

Gary H.

P.S.- a reminder - once the clip is removed there is a lot of spring force on the cap.

 

I have this same fork, do you know if i can fill the oil into the drain hole on the bottom? I've seen some ppl do that

 

tip the bike upside down

only way to do it right is through the top of the fork

 

The forks are off the bike so technically i could have haha. but i was finally able to depress the top cap and get the circlip out so i can fill it the right way

 

The point of removing the cap is so you can change the seals, measure spring length, and inspect the bushings. Just changing the oil on a 30 year old fork leg is a waste of time (plus you'll never get all of the crud out through the drain hole)