GPz 1100 B2 - front fork disassembly???

So I'm in the process of replacing my fork oil seals as one is leaking. Fork legs are off, top caps, dust caps and retainer rings are removed, so far so good.

But how the %@$* do you remove these plugs (pic below) from the top of the leg? According to my manuals (FSM and Clymer) they're unique to the B-models, should have an o-ring on them and the manuals just say to remove them. Yeah right, problem is they won't budge no matter what I try.

Decided to step back before I messed something up, but what am I missing? Is there a trick I don't know or a special tool I don't have? Any advice is much appreciated. Thanks

It has been a while since I did my GPz1100 front end, but if I recall correctly, I used either a 1/2 inch or 3/8 inch ratchet (with a small same sized extension) as the square end fits perfectly into the square depression in the top of the plug.

So they're threaded in? I suspected as much as I noticed that a 1/2" extension square fits perfectly in the plugs. Thing is the inner tubes are damn near perfect, not a mark on them and I'd like to keep them that way - couldn't get a firm enough grip on the tubes in my vice (with protection) to keep them from spinning trying to break the plugs free and had to stop in fear of scoring the tubes, I'll bring them to work tomorrow and see if some heat and an impact gun will help. Thanks.


Edit: Oh hey, 1000 posts!!! Only took me 13 years, guess I need to get out more...

Yeah a little heat and a grip where the headlight ears are should get them to budge. If you mark them there, no one will see it. Just don't clamp where the cap is.
Steve

Ditto as everyone else has said, 1/2" drive extension. Make sure there is no tension on your fork leg, otherwise the fitting will fly out, once loose. I just changed the fork oil on my 82 gpz 750 looks identical.

Just a suggestion, but you might want to consider replacing the front springs with aftermarket ones, that are tailored to your weight and riding style. I changed out mine with this company's Sonic Springs and it made a big difference in ride, dive when applying front brakes, and general handling when compared to the softer stock ones. I went with good brand of 15W fork oil too.

I used a spare triple tree as a clamping device & applied heat using a propane torch. some penetrant wouldn't hurt either. Kroil is supposed to be best, but I use Liquid wrench penetrating spray lubricant. it's readily available & cheap (USA). not sure what's available in Europe.

Well, got it sorted - as always it was a matter of the right tool for the job.

Brought the legs with me to work today and set them up to soak in penetrant all day. After work I stuck them in a big vice and applied our electric impact gun, didn't work. Then tried a 1/2" extension with a breaker bar, didn't work either, the legs just spun in the vice.

Gave up and took the legs to the nearest bike shop, literally 6 houses from where I work - his air gun broke them loose in a matter of minutes, didn't even charge me.

Thanks to all that replied.

So I got the forks apart and ran into another issue - got to love previous owners :dry: .

The B2 has two springs (rebound springs?) on the damper rod, a thin and a thick, but which one goes where? The problem is that when I took the forks apart one came out like pic A below, and one came out like pic B - I can't find any info or pics in any of my manuals and the parts diagram is too blurry to determine which spring is which. Does anyone know which way is correct?

I ran into the same dilemma several years ago...I took my GPz1100 front end apart and didn't pay attention to the order of the springs. Oops. You are correct in that the order of the springs isn't mentioned in the manual and the exploded diagrams don't really show any difference between the spring thicknesses. However, I looked at a very similar motorcycle with a very similar front end (KZ1100-R1) and those exploded diagrams show the thinner springs as nearer the bottom with the thicker springs on top...e.g. your diagram 'A'. That is what I re-assembled my front end to resemble.

Cool Michael, thank you very much. Example 'A' was my gut feeling too, just wasn't sure, glad you could confirm it.

So the rest of the operation went smoothly (after fabbing a couple of tools I needed for the assembly) and everything is back together again.

However, I discovered a major discrepancy between the Clymer and the FSM regarding fork oil capacity and oil level.

According to Clymer the dry fork oil capacity for the 1100 B is 343 cc / 11.6 oz. and the oil level should measure 120 mm / 4.7" with the leg vertical, fully compressed and spring removed. For the same condition the FSM says 322 cc / 10.8 oz. and 164 mm / 6.4".

That's a difference of 21 cc / 0.7 oz and 44 mm / 1.7" :blink: - are they even speaking of the same model?

Should add that the FSM I have in digital copy covers the 1000 J, K and M models with a supplement for the 81, 82 and 83 1000s-1100s, my Clymer covers the KZ, ZX and ZN 1000-1100s as well as the 1000 P series.

Though I dont' consider the Clymer quite as bad as it's reputation I obviously trusted the FSM - if anyone has a manual specific (or more specific) to the GPz B-models and could be bothered to check I would like to hear if those numbers (322 cc / 164 mm) are correct.