1984 Katana 7/11

[pete]

Cheers mate, yeah I'm pretty stoked to be working on my dream bike at last!

As long as I'm patient and take care of it a bit at a time it should come out well.

I did get stuck in last night, but it seems I'm not able to catch too much of a break at the moment. Seeing as I'm having no luck with the motor for the moment I figured I'd rebuild the shocks seeing as I have the seal kits already.

I'm keen to make a tray under the seat for the electrics as well as tool storage space and maybe even a tiny battery, so I need to see how high up the real wheel comes with the shocks fully compressed.

Anyway, I hadn't noticed the second gland nut at the top of the shock and there's a tiny O ring in the seal kit I couldn't see where it belonged, so figured it must be hiding in there.

The nut came out nice and easy, but surprise!



That should be one piece... it's what enables the damping adjustment. I'll have to call Ikon today and see if those parts are available, otherwise I may have to try JB Weld. Not pretty but I don't know how well they'll weld together.

The lock on the other shock is starting to crack also:



So I moved on to the next bit, repairing the mounting tabs on the tail piece. I think I should have a bit more luck with these providing the plastic welding works out ok.

I picked up some acetone yesterday as I believe the trick is to get the pieces stuck together with a soldering iron first by melting some lines perpendicular to the join, then making a slurry out of ABS offcuts and acetone and coat it with that to make it nice and solid.

I have some spare ABS from trimming the rear guard on the wee beastie which I kept for just such a job as this.

I also got the spacers and cushions from Mick Hone to make sure I got the hole size and repair done right.



Made myself a template out of cardboard based on the one remaining mount, it's good for either the left or right side depending which way up it sits.





Cut out the first bit to repair and test fitted:






So tonight I'll take it out to the shed and make sure it looks like it's lining up properly, and once that's set then I'll see if I can get it welded on.

[pete]

Called Ikon suspension yesterday and they have the parts available for the broken locking bits, $29 posted to me so that's a big relief! Should be here this week I think.

I got a good start on the repair work for the tail piece last night and providing the slurry does what it's supposed to do I think it will work out well. I'll find that out tonight.


Test fitted with the first tab ready to go:





Used the soldering iron top and bottom to attach it:








Once that seemed to be set fairly solid I cut the other bits to repair the other couple of tabs, and then noticed a crack in the rear of the tail piece:





For now I just ran the soldering iron across it on the inside but I will see if I can fill that up with the slurry also:





And all four bits "soldered" on and test fitted with the cushions:








While all four are reasonably solid there, they're going to have absolutely no structural integrity, so I really hope the slurry does the trick. The only catch I think will be if the ABS is quite different to what's been used on the tail piece.


Got some offcuts and acetone in here waiting for the magic to happen, will hopefully be able to get that done tonight...

[SVSooke]

If it doesn't melt right a way it isn't ABS.The lowers on the 750EF aren't either and I got to fix them,again

[pete]

Oh it's most definitely ABS Greg, the smaller bits started going soft almost as soon as the acetone hit them.

Mmmmm yummy...



Careful how deep you breathe around that crap! It ain't good on the nose...

Anyway, wiped all the repaired tabs down with some acetone and got the slurry on. In hindsight a tongue depressor or paddle pop stick would've been so much better, instead I used some stiff cardboard as an applicator. I had to put the slurry on a piece of cardboard first to be able to scoop it up, and again a better applicator would've enabled me to take it straight out of the jar.

You gotta be quick applying it because as soon as that acetone starts evaporating, the ABS gets all stringy and wants to stick to everything so it gets tricky to manipulate.









I checked this morning and it's all either solid or close to it, so by tonight all the acetone should've evaporated leaving just solid ABS behind I hope, and then I can sand the chunky bits back a little and see how strong the repairs look.

And after I used up all the slurry I realised I'd missed that crack on the side of the tail light surround again, so I'll have to mix up another small batch to sort that one out.

[SVSooke]

Good that it was ABS,makes your life easier.I had the stuff off the lowers sitting for a week in acetone and it didn't faze them a bit.

[nvr2old]

To me, that's always been the uncertainty of "slurry". If you get the mixture correct, in proportion, it seems to work, but using a 2 part epoxy for plastic, it always comes out correct. It's inexpensive, easy to use, always consistent, dries within 15 minutes, sands easily and I've found has always worked for repairing cracks or literally building new pieces with it. I've repaired a lot of plastic (ABS) parts with epoxy and it never fails to do the job.

Keep up the good work, Pete. Following along with much interest.

[pete]

Yep Greg, seems like it was the right stuff... lucked out on that one

Hey Larry! My concern with epoxy was building up "missing" areas. Some of the side supports were gone along with the top part of the tab and I really wanted to build up all that, so I went the slurry route instead. It's good to know epoxy will do the same though, I'll keep that in mind for next time!

I checked on it last night and all four mounts feel great, they are strong and any pressure I put on the repaired tabs felt like I was going to snap the whole mounting post off the side rail, so I'm pretty stoked with that.

I sanded all the chunky bits and all the cushions and spacers fit just as well as they do on the remaining intact tab.



However I did notice it's not as intact as I thought...



Dunno how I missed that! I have another batch of slurry brewing which I'll use on that and the crack in the tail light surround.

Hopefully the parts for the shocks will be here today and I can start rebuilding them, then I can get cracking on some other things.

[pete]

Had one of those nights last night... success with the tail piece repairs again, slurry seemed to go fine on the two cracks:





I also got the shock parts in the mail but proceeded to break one of them, awesome.

Then I looked closer and compared the whole one to the whole but cracking existing part, and they're not quite the same. Checked the part number on the invoice with the part number on the shock diagram I have and they match up, but the inner diameter of the new one is about 2mm smaller than the original, so trying to force it on to the shock piston snapped it. Figures...

Back on the phone to Ikon this morning.

[pete]

Finished up the tail piece repairs and it's all good to go, just needs a bit of filler or putty on the tail light surround but that will go on as part of paint prep when I get that far.







I also spoke to Ikon about the shock parts and turns out that when the change from Koni to Ikon was made, the piston assemblies are a little different including that part, and the Koni parts are NLA.

Basically the three options I have are to buy new piston assemblies ($350 for the pair), replace the shocks altogether, or try to grind/mill the incorrect parts to fit.

I'm going to give the grind/mill option a try first and because they shouldn't have sent me those parts they're helping me out by sending another two gratis so I can give it a shot.

[posplayr]

Interesting technique with the ABS slurry; I guess i have heard of it before but never seen it done.
I tried to do some plastic welding once with the HF unit. Did not go well at all; incompatibilities of one sort or another and I caved in the tail pieces. It was a los t cause so nothing lost.

I did reinforce my unbroken tabs with cat hair Bondo (long hair FB reinforced). It adds some weight but the heft is more comforting.

I used some JB Weld for a recent repair and reinforcement of painted parts.

[pete]

Yep it seems to have worked well Jim, everything feels nice and solid and there is structure now where it was missing before. To be honest I think I just lucked out with the right materials to work with.

I need to repair the rear guard on the 450 at some point and given the offcuts are from trimming that down, I know that will work well so I'll probably use the same technique.

However, in future and knowing the epoxy works as per Larry's comment, I'd probably give that a shot for more unknown materials.

[pete]

I had some dramas last week when the replacement locking collars arrived for the Koni's. Turns out that the Koni versions are NLA and the ones I got are for Ikons which have a slightly smaller diameter. Unfortunately I didn't realise this (part numbers are the same) and managed to force one on the piston which broke it as they're iron. Serves me right for not double checking first...

Anyway, long story short the three options are new shocks, new piston assemblies, or attempt to file/grind/mill the new locking collars to fit. I chose the latter as my first step and Ikon are sending me another couple as they should've asked me if they were for Koni's or Ikons when I purchased them.

While I wait for them, I filed the one I have down to see how it went and it ended up a little looser on the piston than I liked, but it seems to work. The main reason it's loose though I'm pretty sure is due to the smaller height of the flat face compared to the old one.

I think they will do the trick though as the top eye assembly was able to go in successfully and I can rotate the damping adjustment knob fairly easily also, so I don't think there'll be any issues. We'll see when the other bits arrive and I file them the same and get the shocks rebuilt.

[Nessism]

Hi Pete,

Sorry to belabor the ABS repair method point any further, but I've had good success by laminating a piece of fiberglass cloth over the crack, on the inside where it won't show, to reinforce the joint. This won't work where you have to manage the thickness carefully, but it should work on the inside of a fairing, side cover, tail section, etc. I use general purpose slow dry epoxy.

[pete]

Belabor away Ed! It's always good to know multiple methods to achieve the same purpose as there are situations where one will work better than another.

I arrived home yesterday to find an Express Post satchel waiting, and it was four locking collars from Ikon with a hand written note from the lady I was dealing with. Once again I can highly recommend Ikon's service



So I set to with the file again last night and got two of them to be as good a fit as possible on the pistons. The first one I did was definitely a touch looser than I'd like so I'll use these two instead.



Then I gave some bits on the completely disassembled shock a quick once over with the Mothers and while not looking like new they certainly come up pretty well.



Hopefully I can do a final inspection/clean up tonight and start assembling the first one.

[pete]

I managed to get both shocks rebuilt ready for oil and final assembly last night.

I didn't realise I hadn't quite completely dismantled them, still hadn't removed the damping adjustment rod from the piston:



Installed the new seal:



First piston rod assembly completed:



I then finished dismantling the other one, gave it a bit of a clean and polish, and assembled it also. I now have two ready for oil:



Final thing is to put 80mL's of oil in each and test that the damping adjustment works.

It looks like the adjusted Ikon locking collars are working, the top eye assembly is tightened down solid and doesn't seem to have any issues from the slightly different part in there.

Tonight I should be able to finish them off.