Yamaha TT400 - shocks, air, and funny noises

[paddy]

Hey, I'm pretty new around here (I just finished introducing myself in the New members form). I'm not sure if this is better here or in the MX section; however, here goes.

I just bought a 1988 Yamaha TT400. I have some questions around the shock set up:

1) I notice that the front forks have tyre-like air valves at the top. What are these for? How should they be set up?

2) When pushing the front shocks up and down, there is a lot of air noise. Is this normal or could they be leaking?

3) Someone suggested that I use chain wax rather than oil as it doesn't collect sand quite as much. Is this the case? Are there any disadvantages to chain wax over other lubricants?

Thanks!

[Robert Taylor]

Hey, I'm pretty new around here (I just finished introducing myself in the New members form). I'm not sure if this is better here or in the MX section; however, here goes.

I just bought a 1988 Yamaha TT400. I have some questions around the shock set up:

1) I notice that the front forks have tyre-like air valves at the top. What are these for? How should they be set up?

2) When pushing the front shocks up and down, there is a lot of air noise. Is this normal or could they be leaking?

3) Someone suggested that I use chain wax rather than oil as it doesn't collect sand quite as much. Is this the case? Are there any disadvantages to chain wax over other lubricants?

Thanks!

( In haste ) Use the fork cap valves to bleed out pressure build up, avoid adding air pressure as it can induce seal leakage rather more quickly and also increases seal friction markedly.
These always do sound squishy internally, bear in mind that there is 20 plus years of wear so the likelihood of worn bushings and damper rod piston rings etc is very high.

[paddy]

( In haste ) Use the fork cap valves to bleed out pressure build up, avoid adding air pressure as it can induce seal leakage rather more quickly and also increases seal friction markedly.
These always do sound squishy internally, bear in mind that there is 20 plus years of wear so the likelihood of worn bushings and damper rod piston rings etc is very high.

Thanks for that. (When you have more time), I presume that I should let all of the air out of these valves periodically? Should this be done with the bike at rest/with me on it/at maximum compression/some other way?

[Robert Taylor]

Thanks for that. (When you have more time), I presume that I should let all of the air out of these valves periodically? Should this be done with the bike at rest/with me on it/at maximum compression/some other way?

Yes, bike on a stand, wheel in air and fully extended