Quote from: playmemuzk on January 26, 2009, 10:52:48 PM
Im in way over my head (after looking at this thread)....I'm rebuilding (2) 2004 engines and putting one in my '89....  I couldn't find a gasket kit for a 2004, did you use one from 89-96?  Or did you find a gasket kit for late models?

I simply went to my Suzuki official reseller and I bought a kit for my bike. Original one from the official catalog. The only problem I've seen is that it wasn't properly for MY engine, since it had not the gaskets for the 2 air-injection breather pipes, so most probably it was for a previous version (maybe 2001, maybe before). For the rest they're identical. So I created the gaskets for those holes by myself, using hi-temp gasket material bought from an industrial material reseller and cutting it in shape
The other problem is that original kit is quite expensive... 140€....
I think there's no problem also buying an older kit

Some upgrade 

The handle now it's like new:


Then I started to check the brake calipers.
The previous owner never cleaned them, I use to do a deep clean every 25000km (15500miles) on my bikes.
This is the situation of the front brake caliper after 22000 miles without any maintenance:



So, 1st of all, let's disassembly it (for the rear caliper, remember to untighten the mounting screw BEFORE take the caliper from the bike).
I used a needle to remove the gaskets, WITHOUT pierce them, and CAREFULLY, use compressed air to push the pistons out.


Then I cleaned the parts deeply with a sponge, degreaser and a brush (plus 1500 sand paper and WD-40 for the rusted pivots):


Then, with VERY thin water sandpaper (grade 1500), using wd-40 instead of water, I cleaned the 2 pistons. Here you can see the difference between before and after the cleaning:


And finally I rebuild the caliper (putting some gasket grease on the gaskets before to mount them), here is at the end (I also painted with high temperature paint the pad support):


This is the rear caliper before cleaning:


and after cleaning:


Now let's wait for new brake pads

Whats up with the cylinder bores? It looks like chatter. Some SS sleeved calipers I looked at for my vette the advertise a 2 micron surface finish. I almost looks like a mirror finish.

Quote from: zeusrekning on January 28, 2009, 05:14:21 PM
Whats up with the cylinder bores? It looks like chatter. Some SS sleeved calipers I looked at for my vette the advertise a 2 micron surface finish. I almost looks like a mirror finish.

I don't understand really what you wrote, sorry (remember I'm italian )
But, if I understood correctly: the bore diameter was good and in tolerance.
And, for the surface shiny finish, it's not good: on the cylinders there are many very small grooves, even on the ones with chrome surfaces, and these are VERY useful. In Italy we call them "uttature" (I didn't find any English word for this). These are needed because the oil fits in them and this make the lubrication effective.
If the cylinder surface is completely shiny, the oil doesn't stick on the cylinder and the lubrication became poor.

There's another problem related to these grooves: the tightness between piston rings and cylinders is assured from the high pressure combustion gases that goes between the piston rings and the piston ring cavities, pushing the rings against the cylinder. If the engine runs too much at low throttle opening, the combustion generate less pressure (because of weak combustion), so the piston rings are pushed against the cylinder with faintness.
This cause part of the hot combustion gases to pass between piston rings and cylinder (it's a phenomenon called "blow-by"), and, since these gases are HOT, to carbonize the oil inside the quoted grooves, lacquering the cylinder surface. This is BAD, because this generate lack of lubrication and major oil consumption...
And the only 2 ways to solve this issue are:
- re-bore the cylinder
- manually ream the cylinder with grade 100/150 sand paper, taking care to rotate the paper while pushing it inside, in a way to create 45° grooves versus left and 45° grooves versus right:
NOT in this way:

But in this way:


I hope I replyed to your question

Sorry Gentle, After wakeing up complety I realized I was wrong. I assumed the pic. of the brake caliper showed Stainless steel sleeves, when they were actually the hollow pistons. This is what happens when I ass-u-me.    But anyway I really enjoy the depth of what you have done and the great picture filled post. Good luck the rest of the way.

You should have painted the calipers high-heat RED instead of the stock black/charcoal...

Hi guys!
I'm back again

Let's go on...
1st: if possible AVOID to leave this bike outside... It's bloody frame is made in steel, and Suzuki economized on paint :-( No primer between the paint (probably dust paint) and metal stuff.
After a couple of years outside, these are the results! 

The batterry cage:


The swing-arm and part of the shock absorber leverage  (JUST treated with metal brush and hydrochloric acid, to remove the most part of the rust):



Plus there was heavy rust on the central stand, on the shok absorber spring, and so on... 

Ah, and this sh*t was the steering upper bearing (the lower one was perfect):



So, considering that I don't like to paint, also if I'm quite good with it (I painted my other motorcycle by my own), I had to put a lot of effort to fix these stuffs...

Wow, that is a whole lot of rust! My bikes are always outside, and one of them is showing quite a bit of rust... Shoot, might be time to strip it completely and get it media blasted and powder coated or something along those lines...

Continuing from the previous message

This is how I proceeded:

1st: use metal brush to remove the incoherent paint and reveal the hidden rust.

2nd: close with "american tape" (http://www.oz-q.com/humour/duct%20tape.jpg) the bearing holes

3rd: CAREFULLY use hydrochloride acid, leaving it for 5/10 mins on the rusted parts, to remove the main rust

4th: wash everything with water + washing soda (http://en.wikipedia.org/wiki/Sodium_carbonate) to make acid inert

5th: washing again with clean water to remove soda

6th: treat everything with a GOOD rust converter until the rust is converted totally, then clean them (the ONLY good ones are stuffs based on phosphoric acid, OR the Fertan http://www.fertanamerica.com/; Ferox from Arexons and all the white milky "rust converter" are really assholes: they convert just some micron of rust and create a layer on it, and the rust continue to dig below, making that layer to detach from the surface, with all the paint you used over it)

7th: paint with a good primer paint (I used industrial nitro one):

ehi: the part below the spring is covered with paper and sellotape, it's still back  



On the swing-arm, inside its "arms" I also used a special paint for internal car metal bodyworks (all the parts that are not exposed to direct air).

8th: finish with a good "enamel" paint (again I used industrial nitro one):










Ah, and this, on the left, directly from SKF Germany (I've the official reseller near here) is the new steering bearing (compared to the old one - cleaned, on the right - ):


Will I finish this bike?  

That paint job looks great. You'll probably finish this bike a few weeks before you sell it to buy a totally different project bike...

Quote from: fred on February 11, 2009, 04:38:19 PM
That paint job looks great. You'll probably finish this bike a few weeks before you sell it to buy a totally different project bike...

Eheheh 
Thanks, but I'll not sell it: I took it for my girlfriend. She has to learn. Then, knowing her, she will probably buy some missile, like GSX-R 750 or something similar 

Quote from: GenTLe on February 11, 2009, 04:45:43 PM

Quote from: fred on February 11, 2009, 04:38:19 PM
That paint job looks great. You'll probably finish this bike a few weeks before you sell it to buy a totally different project bike...

Eheheh 
Thanks, but I'll not sell it: I took it for my girlfriend. She has to learn. Then, knowing her, she will probably buy some missile, like GSX-R 750 or something similar 

I know how that goes. I'm hoping that I can get my girlfriend to ride my project bike once it is working again. She hasn't ever ridden a bike before, but the GS is a good beginner bike and I'll send her to the class if she'll go... I don't think seeing it in pieces is helping though, she's like "I've seen you take that thing apart and curse at it for not running, how do I know you didn't miss something?" Hopefully she'll come around eventually...

Quote from: fred on February 11, 2009, 04:58:14 PM
I know how that goes. I'm hoping that I can get my girlfriend to ride my project bike once it is working again. She hasn't ever ridden a bike before, but the GS is a good beginner bike and I'll send her to the class if she'll go... I don't think seeing it in pieces is helping though, she's like "I've seen you take that thing apart and curse at it for not running, how do I know you didn't miss something?" Hopefully she'll come around eventually...

Well, mostly depends from your girlfriend character: mine was used to sail with race sail-ships, run with bicycles, ski and, after 1st trip with me on my motorcycle, she claimed that I had to teach her to ride a bike too.
If your girlfriend doesn't like adrenaline, fast stuffs, and such things, it could be a forcing and she'll never take the passion. Or she will do all but for you only (and this is even worse).
Take care

ALex

Let's go on with rusty jobs 

Ok, give a look here, at the frame  :




Such a filthiness eh? 

So, after removing of the incoherent rust, I acted with my precious converter (since to work it must stay wet, I packed all the parts where I put it):


Then, after removal of the rust converted into dust, I put some primer/anti-rust:




And, finally, black paint






Now, finally, I can start to reassembly everything to form again a running motorcycle 

Nice work with the paint. You are going to have one amazing looking bike when it is back together.

Excellent work man, I love your work ethic.  Nothing to small, and always done right!  Your girl will be lucky when you hand her a bike that will probably be better than when first built!  to you!

  and 

Looks like it is coming along nicely!

Keep up the excellent work.

It is nice to see someone that doesn't ghetto-rig everything.  Great work!

Ok guys, latest pictures here

My girlfriend helped me to put the engine back in the frame (not properly an easy job  ):


The mess of tubes around latest carburetor model:


And my girlfriend looking at them (this is the major satisfaction: her smile looking her future bike!):


And her revenge on me  :


Uhhh, finally I got the last part I was waiting for  :


Here when I closed the chain:


Uhm, I saw a problem when I was mounting the headlight... The thread of left plastic seat was completely gone, and the right seat was damaged:


The material of the headlamp is Polypropylene (http://en.wikipedia.org/wiki/Polypropylene), one of the worst material when it comes to glue it 
But it's a thermoplastic... So I operated in this way: I made the thread hole to traverse the plastic completely, then I found 2 "not rust-able" nuts, I heat them with a bunsen burner, and I melt them inside the plastic:



Then with a couple of new normal screws, I fixed the lamp to the frame )

After this it was a matter of hours to mount the new brake pads and fill the brake circuit, mount the swingarm and try to star the engine...
And I went into a problem 
It didn't want to start...
Well, here there's the explanation:
http://gstwins.com/gsboard/index.php?topic=46805.0

Take care guys, on some thread you can find WRONG instructions if you have a single pickup!:


After re-timing the 2 camshafts, the engine started at the 2nd turn of the crankshaft 
Finally I did a carbs re-synch, and the bike was ready

And here the final results (with my other bike):






Considering that GS was going to be wrecked, I'm VERY VERY happy, and satisfied