front fork upgrade. what seals to replace?
 

Can anyone tell me what seals I should replace when upgrading my fork springs?
Going for hyper pro springs.

Parts from this page:

http://www.yamahamotorcyclespares.co...t%20fork?uID=0

Also, I've been lead to believe this process is fairly straight forward, but is there any kind of walkthrough or photos available here on site.
I do know how to use the search function :-P it's just... There's a few, well... a lot.

Thanks in advance, Tenners!

front fork upgrade. what seals to replace?
 

There's no need to split the forks or change any seals when fitting new springs (unless they're knackered of course).

Just take each leg out, remove the caps, pull the old springs out, pump/tip the old oil out, refill with correct amount if fresh oil, pump them a bit to distribute oil, (with fork compressed) check the air gap, insert new springs and replace the caps. Refit the forks in the yokes and off you go...

I did mine on the bike, no oil swapping at all.

You can indeed change fork springs without removing the fork legs, but it will be impossible to check you have the right level of oil and air gap doing it this way. Different springs, both linear and progressive, displace different amounts of oil/air and require different size air gaps (oil levels) in order to perform at their best.

The Hyperpro springs require thicker oil than OE, so the original oil will have to be changed anyhow, and you'll never get it all out unless you invert the forks and pump it out.

This one of Kev's threads may be of help if anyone's thinking of refreshing their fork oil or changing springs...

http://www.xt660.com/showthread.php?t=4274

Here's a question for you then:

Hyper Pro springs arrived today, with 1 litre of oil.

The manual states that each leg takes approx 650ml of oil.
The HyperPro fitting instructions say 500ml.
I know to measure oil by height in each leg.

Which one is correct? Do i need to buy another litre of the same oil or can I buy the same weight oil from a different manufacturer?


Sorry for all the questions... :newbie:

If you do them on the bike only do one at a time.

front fork upgrade. what seals to replace?
 

Don't buy any more oil, only put the 500ml specified in. The Hyperpro springs have thicker windings, so displace more oil when fitted with the springs.

Assuming you've got every last drop of the old stuff out, put 500ml in each leg. After pumping the fork, all you can do is check the level is equal in both legs. What ever you do, DO NOT set the level to the same as stock or the air gap will be way too small with the new springs in and the forks will get hard/lock up before the end if their travel. Hyperpro/Yacugar don't specify a level (air gap) - I had the same conundrum.

500ml each leg is correct.

Cheers, mate.

Thought so, but wanted clarification.

Owe you a pint.