XJ550R Seca project, fork air pressure?

I see air valves on the top of the fork tubes, but no mention of this in the owners or service manual, are these tubes OEM?

 

nope. Well, the tubes might be, and someone just added air caps. The 550 Seca did not have air forks, any of the 3 years it was sold here.

 

What should I do with 'em Fitz? Ignore them, plug them, or fill them ?

 

Fill em!

 

If you changed the fork oil, and the seals aren't leaking, I'd put about 4lbs of air in 'em and see how it rides. If I remember correctly from back in the day, most early air forks ran at pretty low pressures, like 0 to 6lbs.

Do the caps in the top of the fork come out the same as the original; that is, push down so you can pry out the clip?

Can you pop a cap out and post a pic? The rest of the front of the bike looks stock, so I suspect that someone merely added fork caps with valves in them. Either that, or swapped a set of 35mm tubes into an otherwise Yamaha front end. I suspect the former (aftermarket air caps.)

 

Have you ever tried to put air into a fork tube? Bogus! The closest I can do for my GS1100G is a rounded 10 psi. 6 psi is about half a f_rt, not possible.
Why did they put those on? Were they trying to make a softer ride?

 

Umm, yeah. Use a hand (bicycle) pump. That would have been done to stiffen the forks, make them more responsive supposedly. I don't know how effective just adding air caps to standard forks would have been to begin with. Try it and see would be my course of action; you can always remove the valves and plug the holes with a couple of screws.

 

I haven't put air pressure into the forks, but I used the air valves to blow out the old oil, then took them off to poor oil into the tubes. They may have made the job easier. I'm changing the oil in a Suzuki 550 too, the old way is a little more frustrating until I figured out a procedure to get the clip ring out. The air valves are no faster, if you know how to get the clip ring out. :wink: