Fork questions and general confusion, GS450 ET

[Trevor76]

So I was going to change the fork oil/replace the seals today on my 1980 GS450 ET, but there is no distinction for that model in my Clymer manual.

There is a GS450 EZ listed, which calls for 6.0 oz of fork oil per leg (131mm)
and a GS450 ED, calling for different amounts for each leg.

(I believe I read somewhere that some models were equipped with an anti-dive device on one leg, this must be that model?)

There are other GS450's in there too but I figure mine is closest to one of the "E" models...

Anyhow no listing for a GS450 ET, so what's the deal?

Also, why is fork oil measured in both liquid measurement and the level within the leg?
(ex., 6 fluid ounces and 131mm)

And a question about fork oil itself: The Clymer calls for a 50/50 blend of
10w-30 oil and transmission fluid. Does anyone actually do that?


And do I REALLY need to take the whole fork apart to switch out the seal?
I read BassCliffs write-up, my forks aren't air-assisted so I can't blow them out.

Oh well, I'm off to Autozone to get a jack, a 8mm allen head socket and a cotter pin...

I'll check back here later, thanks in advance for any information.

 

[Nessism]

Focus on the fluid height, not the volume. Measurement is taken with the springs out and forks compressed.

15 weight fork oil works well, or just do that 50-50 mix. Both work.

Your bike is a 450E, the second letter denotes the year. Check the GSR home page for more explanation on this detail.

And yes, you need to pull the forks apart to change the seals.

Hope this helps and good luck.

 

[Guest]

It does get confusing with all the different models' spec's, I know I had troubles working it out when I did it a while ago after painting the lowers etc.

I'm about to do it again though to put the Ikon progressive springs in, so Ed thanks for the tip on level rather than volume, I went by volume last time.

Trevor, I may end up doing this this week, so I should have some pic's up and things to share which may help.

Ikon recommend sticking with standard oil viscosity and level and I'm pretty sure I've got 15wt fork oil waiting for me.

 

[Trevor76]

Nessism Focus on the fluid height, not the volume. Measurement is taken with the springs out and forks compressed.

15 weight fork oil works well, or just do that 50-50 mix. Both work.

Your bike is a 450E, the second letter denotes the year. Check the GSR home page for more explanation on this detail.

And yes, you need to pull the forks apart to change the seals.

Hope this helps and good luck.

Awesome, I knew I had seen that chart somewhere but couldn't remember where. So I will follow the specs for the "EZ" model as it's an '82 and should be identical.

I will need to gather a few more tools before I can do the job. I did pick up the allen head socket last night, as well as a pair of jack stands. I think that I can use the tire jack from my car to get it up onto the stands, I've got all sorts of wood scraps I can use as well.

In the fork seal tutorial written by Mr. Matchless (BikeCliff's page), he has a custom made tool for loosening the allen bolt, which I do not have.
The Clymer doesn't call for such a tool as I recall, so I am going to proceed without. Looks like life would be easier with such a tool, though.

On a side note, I have also seen a tutorial where the appropriate size allen key was cut off at the "L" and the longer side inserted into the chuck of a drill, and the bolt loosened that way.
That was on a Honda site, but same basic principle.

 

[Trevor76]

Scratch that, I read the Clymer again and they DO suggest that you use a special Suzuki tool for for changing the fork seals (obviously Mr. Matchless found it easier to fabricate his own).

Looks like I'm refilling the oil without changing the seals. There's nothing there to make me believe that the existing seals were actually bad, it was just a preventative measure. But I don't have a special Suzuki tool, nor do I have access to a welder and I'll be damned if I'm going to pay somebody to make one.

 

[apopleptic]

*cough*cough*
I'm Looking in my Clymer manual right now and I have basically the same bike. (1980 450S)
Reccomendation is 145cc (4.9 US ounces) and should measure 197mm (7.8")
This volume was pretty close to how much I drained out of my forks as well.
What manual are you looking at?

 

[bccap]

Just did my seals. Followed some of Bikecliffs tutorial and adapted the rest. I also couldn't use the air method. {83 gs750e} Used the volume measure to fill the tubes, then cut off a shampoo bottle pump to the exact length in mm, as Bikecliff suggested, to fine tune it. Regarding the allen bolt. Hampshirehog suggested sticking a broom handle down the tube to give it some resistance if it didn't unscrew on its own. Those allen bolts were really in there on my bike, had to use an impact driver on one of mine. I definitely wouldn't recommend using an L shaped allen key. Too easy to strip the bolt. But I didn't have to use the broom handle. It did unscrew on its own. Then used the fork like a slide hammer, as per Svsooke's suggestion. Out popped the seal. { I won't mention the 3 three days I spent slide hammering, with the allen bolt still in. Felt like an idiot ! } Anyway, I got it done. Hope some of this helps.

 

[Guest]

Figured I'd best check this out before doing it again myself, and this time I've used the factory reproduction manual I have (didn't have it the first time).

It doesn't give a cc reading, it just gives the height, and it actually depends on what country you're in! The two measurements are 186mm and 197mm, but I'm pretty sure 197mm is what we're looking for.

But does anyone have a clue what the numbers relate to in terms of countries? I'm referring to the E-01, E-02, E-04, E-17 etc. that it lists against various different values in the service data.

 

[Trevor76]

OH GEEZ! now I am confused and frustrated. The forks on my bike look nothing like the tech drawings in the Clymer.
(I have the Clymer with the photo of the maroon 450t on the front)

The Clymer shows a pair of forks with bolts/caps on each side.

My front right fork -if you are seated on the bike -has no bolts to undo, so that the axle must be slid out. I checked the schematics at bikebandit and this is how they look there.

p.213 of the Clymer manual has the following numbers listed for the 450 EZ:
178cc or 6oz US ounces/6.3 imperial ounces
131mm/5.6 in.

One of the reasons I don't like Clymer. This manual covers ten years worth of production ('77-'87), with numerous model variations. Obviously the book would be a lot thicker if they showed pics of all the variants, but at least they could make a note of the differences...as Pete already knows from my other threads this bike has been monkeyed with quite a bit so I can't take it for granted that any of the parts are what they seem. In fact, there is an "L" stamped in the motor before the engine number, does this signify that it was originally in a L-type frame?

Anyway I'm going with 197mm. That's my final answer.

 

[apopleptic]

When I picked up my bike I had a lot of confusion due to the different models of 450 made in 1980.
Mine turned out to be an S which is an E with the fairing (which isn't on my bike, it's on my floor).
Looking thought the mighty internet gathers me this info: In 1982 they sold a GS450TX and a GS450TXZ and a GS450TZ

It looks like their fork has a different cap than what mine has (1980 450S)
Can you upload a picture of the bike? it can help get you the information you need.
It is possible that it was registered wrong by someone who thought they knew better and said 'Oh it's a T and that means 1980'
the PO of my bike registered it as having like 56k when it only had 16k. know way to fix that except drive it 40,000 more miles

 

[Trevor76]

I realize that these don't show much at all, but I took them today while I was removing the forks. I will take better photos in the next few days when I have another opportunity to work on the bike.

[/IMG]

[/IMG]

[/IMG]

 

[apopleptic]

Boy, sometimes I amaze myself with how confusing I can make things.
this looks about right for your forks. (I think I was wrong about your bike being a different year)
http://www.gssuzuki.com/fiche_secti...y=Motorcycles&make=SUZUKI&year=1980&fveh=2093
Please don't purposely make your forks have different amounts of oil unless you are 100% sure it should be, I am pretty sure that would be bad.

 

[Guest]

Definitely a bit awkward from those pic's, but they do look like standard E/S forks from what I can see, so 197mm should do ya fine in both legs.

I'm just uploading pic's from starting on my Ikon installation tonight so that may help you out some once I've got my thread updated.

 

[Trevor76]

apopleptic -the second technical drawing looks like the one. Those are the style of caps that I have. BTW, isn't Wilkes Barre where the Penguins have their farm team?

Pete, I do think now that they are actually the stock E/S forks and that 197mm is the answer. I will be moving my confusion back over to the electrical forum soon!

 

[apopleptic]

apopleptic -the second technical drawing looks like the one. Those are the style of caps that I have. BTW, isn't Wilkes Barre where the Penguins have their farm team?

I think you are right.
We also have the Lion's Head Brewery...
I'm not from here originally so that's all I know

 

[Nessism]

The fork oil level is not critical, I think some of you guys are over thinking this. As long as the damper rod is covered the damping will be there. The other thing the oil level controls is the amount of air trapped inside the forks. When the forks are compressing this air is compressed, which provides a little anti-bottoming assistance.

I'd fill the forks to 5.5" from the top with the springs removed and the forks compressed. This works or the larger GS's, and will work for the 450 too.

 

[apopleptic]

The fork oil level is not critical, I think some of you guys are over thinking this. As long as the damper rod is covered the damping will be there. The other thing the oil level controls is the amount of air trapped inside the forks. When the forks are compressing this air is compressed, which provides a little anti-bottoming assistance.

I'd fill the forks to 5.5" from the top with the springs removed and the forks compressed. This works or the larger GS's, and will work for the 450 too.

Is the info I have correct in stating that it's more important that the fork oil be level in both forks versus exactly how much there is?
I was told uneven level will make the fork compress unevenly making the front wheel kind of twist under hard braking.

 

[Guest]

The fork oil level is not critical, I think some of you guys are over thinking this. As long as the damper rod is covered the damping will be there. The other thing the oil level controls is the amount of air trapped inside the forks. When the forks are compressing this air is compressed, which provides a little anti-bottoming assistance.

I'd fill the forks to 5.5" from the top with the springs removed and the forks compressed. This works or the larger GS's, and will work for the 450 too.

Makes sense Ed, and you should know by now I tend to over think things

Thanks for the tip, I'm just working the measuring technique out at the moment actually

Is the info I have correct in stating that it's more important that the fork oil be level in both forks versus exactly how much there is?
I was told uneven level will make the fork compress unevenly making the front wheel kind of twist under hard braking.

Yup, for sure.

While there are modern bikes that have rebound damping in one leg and compression damping in the other, the forks are designed for it.

In these old GS' I reckon you'd need one hell of a good fork brace to be able to cope with uneven oil levels...

 

[bccap]

The measuring is easy. Just take the pump off an old shampoo bottle, or even a windex bottle. Pump is better because you don't have to hold up a container to catch the spray. Cut the tube 5.5 inches from the bottom of the cap. Fill up the fork til it looks like four or five inches from the top. Stick the tube down the fork and pump out til your sucking air. Repeat on the other fork and you'll have perfectly level forks.

 

[Trevor76]

I did it today, got an unexpected bit of free time and ran to the garage. Basically I filled an empty (and rinsed out) shampoo bottle with 5oz of 10w-30 oil, and 5oz of ATF. Then I shook it up. I then measured (roughly) 4.9 oz of the mixture and poured it down each fork tube -spring out, fully compressed. I then used the spray bottle pump-thingy method, with the tube cut off to exactly 197mm. I must've done it right because it only took a few squirts in each tube to empty the pump. Re-assembled and ready to go back on the bike.

By the way, a pair of Honda cb350 fork gaiters work perfectly for the GS450, pics tonight if I have insomnia after work, or tommorow...

Speaking of work I gotta run, thanks again for all of the help and insight.