1980 Maxim Air Assist (?) Forks

I will eventually be rebuilding these forks, and neither the factory manual nor the microfiche show these air joints on an '80 Maxim. They look (to me) like items 51 and 52 here from an '82 Turbo, maybe not? Anybody know how they come off?

 

Anybody have any experience removing the air assist cap pictured? Anybody? Any tech writers out there?

 

Interesting. It looks like a standard inflation valve cap. Is it plastic or metal? If metal I would consider a tiny drop of Kroil.

 

I apologize for not being clear. My question is regarding how to remove the entire assembly from the top of the fork tube.

 

The 650 Maxim did not come with the air assist forks. That looks to be an aftermarket/custom setup. Factory parts would have a molded/cast appearance. Not the machined surface shown.

Does the center of the cap unscrew to allow access to the internal parts?
Do both the schrader valve, and hose nipple unscrew from the body?

Ghost

 

Exactly, not sure where the units came from. The hose nipple is cast in to the assembly. Not sure about unscrewing the schrader or center cap. I was hoping someone would have recognized it. Where is that darn tech writer when you need him; off in his lab cooking up New Year's solutions to "podster tuning problems" no doubt...

 

RickB,

MiGhost wrote:
The 650 Maxim did not come with the air assist forks. That looks to be an aftermarket/custom setup. Factory parts would have a molded/cast appearance. Not the machined surface shown.

Does the center of the cap unscrew to allow access to the internal parts?
Do both the schrader valve, and hose nipple unscrew from the body?

Ghost[/quote]

Ghost, Unless your talking about the the '80 model only my 650j does have air-assisted forks. It has the shrader valve in the center of the fork cap under a plastic screw on cover. I've never seen this set-up before tho'. Rick, where does that hose coming off the valve end? Like Ghost said...looks like a aftermarket mod that would let you put air and oil in the forks through that cap.

Gary

 

None of my XJs have air-assisted forks, but just based on appearance, the hose w/screw clamp, etc; that's not a "factory" piece.

My guess would be that it unscrews; but that is only a SWAG.

 

Thanks guys, I guess I'll just have to be extra careful removing them. FWIW, the hose runs from one fork to the other as seen below. I hope to reverse the caps and run the hose under the instruments.

 

Rick,

Yeah, on the "extra careful" part. I looked at the forks diagram for your 650G (I'm sure you did too) and it shows non-air assisted hard caps w/circlips and rubber plugs on top. Those caps are holding those compressed springs in somehow. Like BF said, maybe they screw in. When you do get the caps off please update this thread; I'd like to see how those caps are located.


Gary

 

Gary. The air assist fork on the 650 Maxim started with the 82 model.

Rick.

The tops of the inner fork tubes on my 83 XJ750K are threaded to retain the plastic/rubber fork cap.
The 82 XJ650J uses the same fork caps. Along with the same inner fork tube as the 80 XJ650G.
Gary should be able to comfirm that the tops of the fork tubes are threaded.

Those adapter pieces should screw into the top of the inner fork tubes replacing the fork caps.
I would suspect an O-ring seal to be used also.
You may have to slide the tube up through the top crown to get enough clearance for the hose nipple, and schrader valve.

Ghost

 

So much for me being extra careful. I haven't broken anthing YET, but as you can see from the first photo I've "ggrrr'd" up the left fitting somewhat. The units appear to be homemade and I swear they are glued/epoxied/etc. in place. The air fittings are epoxied in place, the screw holes on top don't go all the way thru, there are some partially drilled holes in each side, and while the "lips" (different height lips) make them look like they're two pieces, they appear to be one piece... bizarre.

I am considering applying some heat to the tops of the fork tube, but I am concerned. So far I've tried: rubber mallet, hammer, pipe wrench, vise grips, screwdriver... Ultimately, I suppose I could cut them off.

 

I agree that they're homemade (or cheesy "period" aftermarket) and also that there's a good possibility that they may likewise be epoxied in place.

I wouldn't heat the fork tubes YET. I would try heating the silly caps, not so much worry about the expansion factor but to see if it will help you break loose any misguided adhesive that may have been applied.

I'd heat them up, let them cool, heat them up, let them cool; and then get back on them with a pipe wrench with a big long extension on the handle and see if you can break them free.

If you really want air-assisted forks, it would be much easier to then retrofit Yamaha air caps from a bike that came with them.

 

Rick,

Ghost is correct. Plastic caps with "Air Adjustable" embossed on them screw into the top of my forks. I'm going to learn how to post pics to threads real soon. :roll: I'd still be careful. When I initially compressed one of my caps to remove the circlip my holding tool slipped and the cap shot out the fork and left a indentation in my garage ceiling. 8O I bought a furniture clamp. :lol:

Gary

 

As those holes are directly opposed. It would be my guess that they were used to tighten the piece down by placing a length of round bar stock in them to act as a T-handle.

I second Fitz's recommendation on heating the cap piece instead of the tube.

If you still want to retain the air assist. You should only need the cap bolt, air valve, and cap from the following bikes.

80-81 XS850
81-82 XV920 VIRAGO
81-83 XV750 VIRAGO
82-83 XJ650 Maxim.

Ghost

 

My 81 maxim 650 has a schrader valve in the center of them? Air assist or.no?

 

Yes. Those would be the air assist forks.

Ghost

 

I finally got around to taking those caps off today, and as you can see, they did not go willingly. They were interference fit/epoxied to the fork tube. After applying some heat, I ended up putting a vice grip on them and beating the vice grip upward with a hammer to get them off. I feel oddly relieved to have them off.

 

So...they were made by someone who had access to a lathe, but didn't know how to cut outside threads.....excellent

 

The next question would be.

Was the cap nut drilled to allow the air assist mod to actually funtion?

Ghost