GS Twins Wiki.

[pete]

Excellent! Thanks for starting this.

We need to get the ignition stuff in here also.

You can retrofit the points setup (must include coils) from the earlier 400/425's (4 valve) onto the 80 - 82 450's. (Dunno why you'd do this but you can)

The Dynatek DS3-3C kit is designed for the 400/425's (4 valve) but can be used easily on the 450's by retaining the mechanical advance, using a spacer that Dynatek can provide, and by running a separate wire for the oil pressure sensor. The kit comes with coils.

The 83 and onwards 450 (4 valve) ignition setups will retrofit into the 80 - 82 450's (4 valve) providing the mechanical advance is removed and the signal generator and rotor are also replaced.

The 500 ignition setups appear to also retrofit as above, but the advance curve is slightly different.

[Mekanix]

If anyone has any links or photo's that I could add to each section, That would be great.

I'm combing through the old posts for things that I could add here instead of using the search.

[pete]

All my pic's are in libraries here:

http://s594.photobucket.com/user/sta...y/GS450?page=1

There are some comparisons with the stock ignition and Dynatek in here:

http://s594.photobucket.com/user/sta...Dynatek?page=1

[Mekanix]

Added them Pete

[pete]

Nice one! It's coming together well.

[JBender]

Have you thought about a free Wiki hosting service, like Wikispaces? One was started by some 300ZX enthusiasts that I've helped a bit with, you can see here: Z32 Wiki. It's free, and the editor is like using the forum, so no coding knowledge required to make or edit pages.

I would very much like to help with something like this, as information is fragmented across multiple websites, forums, etc and it's often hard to get authoritative information. If a number of people chipped in wherever they have knowledge or by consolidating scattered information, it could be a great resource.

[Mekanix]

Have you thought about a free Wiki hosting service, like Wikispaces? One was started by some 300ZX enthusiasts that I've helped a bit with, you can see here: Z32 Wiki. It's free, and the editor is like using the forum, so no coding knowledge required to make or edit pages.

I would very much like to help with something like this, as information is fragmented across multiple websites, forums, etc and it's often hard to get authoritative information. If a number of people chipped in wherever they have knowledge or by consolidating scattered information, it could be a great resource.

I have thought about it but this doesn't have enough information yet. Its just a bit of the stuff I know and what I can find in the manuals.

[eran_k]

Can i use a 500 block and pistons on the GSX400 bottom and the GSX400 head (8V) ?

[Mekanix]

Can i use a 500 block and pistons on the GSX400 bottom and the GSX400 head (8V) ?

Yes but the pistons likely won't work. There might not be enough material in the piston to cut out the valve reliefs.

However you might be able to find another bike with the right piston for the job.
I'd check honda civic pistons for size and fit.

[Big Rich]

520 chain conversions

Little bump for the twins thread...... I dug up all this info and figured it's a good idea to have it here. Pretty easy to sort through all this on JT Sprockets website too.

Here are the stock GS450 sprockets (I'm just guessing the GSX400 and other vintage twins are similar if not the same):

http://www.jtsprockets.com/catalogue/model/5704

The old GS300 rear sprocket has the same dimensions, but uses a 520 chain instead of 530:

http://www.jtsprockets.com/catalogue/model/5688

But the front sprocket is completely different. Luckily, Suzuki decided to use a similar sprocket on their GS500 with a 520 chain:

http://www.jtsprockets.com/catalogue/model/5718

Be aware though: the front sprocket from any year GS500 will fit a GS450, but the early GS500 models did not come with a spacer behind the sprocket (the late model GS500F sprocket listed above does have the spacer built in).

Hope this helps somebody trying to cut weight / improve performance a little bit.

[pete]

This is all good info guys... if my current situation is what I think it is I may be chasing a GS500 ignition setup to replace my Dynatek. Not sure if that's the case yet or not but it ran on 1 cylinder again yesterday when I was almost home and it was definitely no spark on the left side.

Got to look into it last night and I had spark both sides. This is exactly what happened when the right Dynatek module died, not sure what's going on there but I guess my bike doesn't like Dynatek modules as I don't see others having this issue

[Mekanix]

This is all good info guys... if my current situation is what I think it is I may be chasing a GS500 ignition setup to replace my Dynatek. Not sure if that's the case yet or not but it ran on 1 cylinder again yesterday when I was almost home and it was definitely no spark on the left side.

Got to look into it last night and I had spark both sides. This is exactly what happened when the right Dynatek module died, not sure what's going on there but I guess my bike doesn't like Dynatek modules as I don't see others having this issue

Yup since you already have the wiring hacked its easy to put the 500 parts on and its allot like the dynatek just without the hassle of the mechanical advance, Not to mention parts available everywhere :P

If you don't like the prices you find. try ADIDASGUY on the gstwins forum
I got the plate, rotor, coils, cdi for I think $80 (I got other things too but that's what I thought it would equal out to)

[pete]

Cheers Stephen... I managed to bastardise my two dodgy Dynateks into one good one, or at least so far it's good. Did a few laps of my favourite local roads to scrub in new tyres and it was on two cylinders the whole way which is more than it was doing earlier in the week.

I'll see how I go when I get some funds again, but hitting up Addy might be the way to go as the prices over here hurt my eyes...

[Chuck78]

Stephen, I often get confused in references here on the compatibility between models. When you refer to the GS400, GS450, GS500 compatibility, I often wonder if you are referring to the 80+ GSX400's that Canada got that I believe are a smaller bore GS450 with the 4 valve per cylinder (8 valve) heads and plain bearing bottom ends. If you'd get a chance to edit posts and state which you were referring to (77-79 GS400/425 or 80+ Canadian GS(X)400 4 valve per cylinder 8 valves total), that might help clear my confusion. Correct me if I'm wrong on any of that info. Didn't you use the 4v/cyl head on your Frankenbuild?

[Chuck78]

I came here hoping to get a little more info on the 77-79 twins particularly. I am dreaming up my project for next year after putting my 920cc GS750 (532 lbs stock wire wheels single disc) on a major diet and getting it down to the stock GS550 wet weight of about 485lbs (far more superb handling at that weight, I am very pleased!), I am wanting to try and do something even drastically lighter with an emphasis on excellent cornering and a stripped down barebones racer theme (no "cafe seat" or any useless cosmetic changes). I may be able to get my neighbor friend to sell/trade me his barn find GS425 in near original condition aside from plugged up carbs and rotted tires. I had dreamed of trying to hot rod a kickstart 1st gen GS425 engine and installing at least 2 Wiseco GS750->844 pistons to make a 10.25:1 449cc.


The thought of a Wiseco 844 piston'ed GS400/425 kicker engine with rearsets, battery/starter/centerstand/etc deletes, suspension upgrades, etc is very alluring to me despite having a big 4 cylinder bike.
With the GS425's larger sleeves, I could probably get some custom JE 10.5:1 71mm pistons bored into there, and maybe JE would still have specs on the custom set they built for GSR member 49er to ease the cost down a little. That would give me a 475cc thin-sleeved screamer. I had even thought of trying to get some GS1000 8V sleeves (70mm stock bore) shortened and installed in a GS425 block to get some 73mm JE pistons to give me a high compression 502cc twin. I'm sure that would run me an extra ~$750+ that would be very tough to get back out of a small GS twin if ever reselling, but the thought of doing something custom like that and the idea of being able to do a battery delete capacitor, starter motor and flywheel delete, GS1100E swingarm, 2-1 exhaust, center stand delete, rearsets, passenger footpeg delete, trunk delete, shaved down seat, CBR1100XX lightweight floating rotor and ninja/GS500 caliper, down to about 330lbs dry weight to drastically improve handling and performance while also running a modified engine... well I think the bike could feel fairly impressive on acceleration at that stage of mods.