Gonna do the fork seals at the weekend ...how much fork oil?

How much fork oil do I need for a XJ700 Maxim X please guys?

Looking to get the fork oil tomorrow at the bike shop near work & do it Saturday.

I was thinking 10 wt. oil for it, but a mate thought we should use 15 wt. as it's an older bike???

Recommendations & quantities please fellas!

Many thanks ....

 

Manual calls for 10 wt
13.2 US oz
389 cm^3
or
13.7 imp oz

Bleed the air out first or you'll be surprised (but it's low pressure)

I suggest tearing them completely apart so you can thoroughly clean them, but you would need a tool to reach down into the fork tube and hold the retainer...and I'm not sure if the European version is the same.

Be VERY careful when you refill the air charge. Don't even try to use a full pressure compressor since the forks hold almost no air. Max pressure is 17 psi and exceeding that will blow the seals that you just installed.

You need each fork to have the same air pressure and you can't use a tire pressure gauge to check since it will leak too much air in the process.

You'll need to regulate the air pressure source before you inflate them....OR just run with zero air pressure for a little softer ride but you might not like it.

 

Mike is right on with the numbers. 13 oz US is easy to measure...but trying to accurately measure that 0.2 is tough. I've found that it matters if you are way off (e.g, 10 or 15) but whether it's 13 or 13.2 exactly doesn't seem to affect the forks.

 

I wouldn't change the weight just because "it's an older bike."

Heavier weight fork oil will "stiffen" the damping action and slow the forks slightly. It's a matter of rider preference. I'm no featherweight and I run low bars, so I usually change up one weight. A lighter rider or on a bike with taller bars you might want a more quickly-responding fork so in that case I'd stick with the 10W.

If the forks are "sacked" with age, the best remedy is to fit new Progressive Suspension fork springs. The stockers do sag quite a bit as they get older, and the Progressives are better anyway.

 

I'm looking forward to the update on this since I'm planning on doing my forks as well.

 

Cheers guys

Can't be any worse than they currently are .... not really damping at all at the moment due to the seals being shot :roll:

After reading the comments, I think I'll stay with the 10wt as should be in the bike, unless .... as I weigh in at about 14.5 stone & regularly take pillions you guys reckon I should step up a grade?

Mike, it is a US bike buddy. It was inported into Ireland before it came to the UK.
Not actually sure if they sold it in Europe as wasn't the 700 Yamaha's answer to the 4% tax on 750's when the US government were trying to help Harley out in the 80's?

 

i would take the forks apart and clean them, when I did mine it was full of sludge at the bottom of the tube.

 

+1. If you're doing seals and dust seals then you should pull them all the way down and clean them out. I got grey-green mud out of one of my bikes, nothing resembling oil.

 

Re: Gonna do the fork seals at the weekend ...how much fork

give yourself time and space. Nice clean area to put parts after they are cleaned. It is a messy job, one that is just about on par with rebuilding calipers as far as the mess factor is concerned. Take your time. I'd recommend taking one fork apart, leaving one together. That way you have a reference. It's pretty straight forward. I'd take a break after breaking one fork completely down, then clean it, take another break, then do the other one. There is someone that posted on here that you can actually get a pice of 1.5" (don't quote me) piece of pvc about 3' long (1meter) and use it as a fork seal driver. There are other ways to get the seal to seat, but I think this way is safter for a first timer.

 

Cheers for all that extra advice guys I'll be doing it with a mate who builds his own choppers, so I'm sure he'll have the brains to do the job methodically.
I'll print this thread out to show him everyone's comments & suggestions!

 

good point mike, I didn't do that, and ended up with a momentarily missing bolt and I wore that fantastic smelling fork oil.

 

Well at long last got the fork seals & oil done this last weekend.
We used an old hoist to hold the front of the bike up onto it's rear wheel so we could take the front apart without worrying about it falling over.

Took the 1st fork off, tried the valve & no pressure in there at all! Then stripped it down using a couple of trays to put parts in & one to drain out the graphite coloured old oil ... Nice, not!

Got it all apart & we even made up a new tool using an old axle bolt & another long bolt welded together, so we could use the axle bolt head in the socket at the bottom of the fork & the other end with the bolt head we could get a spanner on ... not bad for 15 minutes work, considering Yamaha's tool for the job is reputed to cost £400!
Got all the dust seal & oil seal out, cleaned it all up, looks like it already has a set of progressive springs in it (were they standard on the Maxim X?) refitted every thing in reverse order, added fresh oil, then used a manual car foot pump to repressure the fork to 15 PSi.
The other fork seals were intact so we decided to leave them alone as there was still pressure in the fork when we let the valve off as well. We still stripped the insides & spring out but had to drain the ouil out the top as the drain screw head looked like it had seen better days & didn't want to snap it on a Sunday afternoon as I use the bike for work as well as play!

Put it all back together & heck ... I got suspension on the front of my bike!!!!!
It feels so much better having these done, as now I can corner without wondering if the front end is going to let go on me :roll:

Also worth noting that the fork clamps up by the clocks were barely finger tight & I'm glad that we found this out before I got a fork in the face 8O

Just got to change the worn tyres for a set of Avon Venom's & she'll ride like she should, if not better, as all our choppers in our club run on this choice of tyre, which gives amazing grip 8)

Cheers again for everyones help & encouragement.
Oh and sorry I forgot to take my camara round to document it, although now I know what I'm doing it wasn't too hard a task to do as long as you are methodical & as was said earlier in the thread, do one at a time so as not to muddle the parts up!