need solid input ref fork adjustment / oil

[Shadowwolf167]

Ok guys, need some solid input here. I have an 04 limited edition (not that that matters mechanically) I've seen indications on the forks that the seals have been leaking and the front end is feeling a bit soft. It's time to swap the front tire so i've decided it's time to replace the fork seals as well. Dealer wants to a$$-rape me with the labor and i'm a capable mechanic so it seems i'm gonna be doin this with the help of a buddy. I've seen several posts with regard to how to raise the front of the bike, however if anyone has some useful diagrams / photos / tips for compressing the forks etc. i'm all ears. Furthermore i've been reading and have a few questions with regard to fork oil viscosity. uh, let me put it out like this... I'm 6'2" nearly 300lbs i don't have the spare cash to get heavier springs right now so with that in mind can any of you give me some solid input as to what the best oil weight would be as well as the best compression / rebound adjustments I can make on the stock forks. I live in a rural area with most of my riding on level curvy roads. I'm not a wheelie / endo guy and my girlfriend frequently rides with me. Any and all help is greatly appreciated! oh and one more question, is it necessary to replace the dust covers when replacing the fork seals?

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[sixpack577]

I wouldn't say replacing the dust covers is a must, but they are only about $15, so it's worth doing. The set of 4(with the oil seals) can usually be had for around $40.
Going with a heavier oil will slow down the responsiveness/action of the forks some also. As far as adjusting the dampning, I'de imagine you'de want them both pretty stiff for your weight, but they are more of a preference and how hard/soft you set them is up to you. They do however need to be set correctly so you don't have a sloppy double bounce when you compress the forks.
Changing the springs, even though out of the question now, is going to be the only way to get the forks to perform at their best for you.
The factory service manual is a free download from this site, and it will help you out alot.
Search for this thread "Jinkster attacks suspension" He'll show you how to set the sag, and get a good overall setup for you. The front and rear suspension work together, so if one is good and the other is off, it's going to affect your ride.
Whatever you need to know, someone here has the answer. If your question hasn't been answered it's most likely because the right people haven't seen it yet. You can always come back and type "bump", that'll get it back in the new posts.
You can also ask TufBusa, he's a trackcoach, and one of the guys you want to ask about suspension.

 

[Twobrothersbusa]

No way you'll ever get optimum suspension set up with stock springs. As was suggested, look up Jinkster's post about setting up laden sag...Given your weight, you'll find that the stock springs are too soft to set up the initial setting. Even cranking down the preload to full you'll have too much compression on the stock springs. You can go to a heavier oil, but it will be a small band aid to the real issue which is springs on the Busa. Light weight guys can use the stock springs if they are in the 150 to 180lb range with gear. Much over that and you have to get into some serious changes to have a good setup. I too have leaned on Tufbusa for help in the suspension area...(ok lots of areas) he has lots of insight that can help you make good decisions about your bike. Good luck.

 

[Twobrothersbusa]

Re-reading your OP.

With my limited experience I would:

Screw in the front spring preload adjustment to its max setting.
Dial in two clicks on the upper and lower from the stock setting.
Go to a 7 weight oil.

Screw in the rear shock spring preload two turns on the spanner from the stock setting.
Dial in two clicks on the upper and lower from the stock setting.

Regards,
2BB

 

[Shadowwolf167]

Just the type of input i was looking for 2BB much appreciated! but curious why the 7 weight oil? isn't that pretty much the factory visc?

 

[Twobrothersbusa]

I thought the Busa was the same as the GSXR1000 with 5 being the stock oil.
All I was suggesting was moving to a bit heavier weight oil.

Just the type of input i was looking for 2BB much appreciated! but curious why the 7 weight oil? isn't that pretty much the factory visc?

 

[Shadowwolf167]

Just wanted to post a quick thank you to you guys for your input. Got everything changed this weekend went with a 15wt fork oil originally went all in on preload but this really made it a bit too stiff (maybe due to the added oil weight) so i backed out 2 lines and it feels really good. 2 clicks in on rebound and set the dampening at the stock 9 clicks (glad i checked this as i found the forks were not set equally from the dealership as i've never screwed with them. probably contributed to the seal failure!!! Also 3 -4 turns on the rear spanner and the bike feels much more nimble with and without the fiance on board! thanks again! Ride Safe!