Just remembered and don't know if it's any interest to you - but a guy on the GSR worked on an electronic ignition or ignitor for his 450. I believe he ended up going with a Dyna from another model and retro-fitting it to his motor.

Either way, his name is Pete on the GSResources if you want to look into it.

Just bought a clean 05 GS500F bottom end off of ebay. Should be here in a week. I'm going to grind one of my heads down a little, fit a APE CCT, and fire it up. Hoping to have something running within a month or so.

Note to self:

RGV250 Model year 91 & 92 (M&N) get the banana swingarm. 93+ is double braced, with the U link linkage.

Quote from: burning1 on October 11, 2011, 07:53:32 PM

Doing some research, it looks like the Yamaha YZ250 petcock is a direct, bolt on fit for the tank. Good deal, since it's a mechanical 3 way petcock, with a downward facing nipple. Not confirmed, but the fuel spigot does appear to be about the same as stock, which seems fine for race use on the GS. Gasket cross references to be the same as the R1. Cross referencing the R1 petcock against Pingle's adaptors indicates that the bolt spacing is the same as for our GS500. Gasket is very very similar, pretty much the same. Cost for the full kit is ~$15.

Planning to buy one, experiment. Will post a new thread if it works out.

Didn't work out eh? ? Any updates? 

Sorry for lack of updates.

The short version is that I have the part and the tank, and I'm confident it'll bolt on perfectly. The long version is that it'll be a long time before I'm ready to install the tank and fill it, and we won't know till then. Would like to confirm that there are no leaks or unexpected issues.

The yamaha petcock looks like it'll flow well. It's a simple on/off petcock, and may not be perfect for street use. But great for racing.

I took some measurements of the GS450 rings, to see if I could save some money on after-market options. Here's what I found:


Top ring
Thickness: 1.18mm (manual says 1.17-1.19)
Width: ~2.8mm
Type: Rectangular (Barrel face?)

Middle ring
Width: ~2.82mm
Thickness: ~1.2mm (Manual says 1.17-1.19)
Type: Tapered


Oil rings:
Stack thickness: 2.90mm total
2.22 Ring width
0.46 Ring thickness

2.55 spring width
2.25 spring thickness

Measurements have some margin of error - I didn't have a ball anvil for my micrometer, so the curve of the ring introduces a little error. And there was some surface rust, so again, margin of error for thickness readings.

However, I included manual spec where I could, from the GS500.

Short version, is that there don't appear to be many readily available aftermarket rings for the GS450.

Running into another snag... It looks like the largest dome the stock GS500 head will accept is 60mm, and unfortunately, both the KZ1000 and GS450 use larger domes than that stock. KZ1000J dome is 65mm on a 69.5mm bore. So, looks like this project will never be a trivial 'drop in' project for anyone who tries it.

It's really annoying how often this thread shows up when I do google searches for KZ and GS parts.

Wait til other people find it with Google searches and then bombard you with questions........

Burning, I know a guy that worked on a lot of Suzuki's for a couple decades. I'll ask him if he knows of any good drop in pistons for the gs450.

Thanks! Problem is really with GS500 head at this point, so what might work with the GS450 may not with the 500.

I sent the link for this thread to my friend, and here's the reply I received:

I would skim GS 500 head as far as possible, about 1mm above valve seat, and probably on a 1.5 degree angle towards exhaust to get an asymmetric chamber.
Use GS500 pistons, modify crown for 0.038" clearance
Dowel holes will need re-sizing and made vertical in relation to block to block
The 8 valve heads are GSX in Europe
I know there is an 80bhp 'GS500' running around with modified SACS 4 cyl head (outer ends cut off)

Take from it what you will - hope it helps out somehow!

Please thank your friend for me. I appreciate that he took the time to look at this thread.

I will have to digest what he said a little.

Our own Bob Broussard built an 8 valve GS500 head... I have been thinking more and more about it, as there are lots of options for 72mm 4 valve pistons... And the 8 valve heads make for nicer combustion chambers and better breathing.

also consider the FJ1100-1200+ pistons....and machine for your use..... you can get them from legends car builders cheap....for the old ones....  just another option.... and if i remember they are same wrist pin diameter

I am totally subscribing to this. Awesomeness will ensue.

Quote from: werase643 on February 27, 2012, 03:34:46 PM
also consider the FJ1100-1200+ pistons....and machine for your use..... you can get them from legends car builders cheap....for the old ones....  just another option.... and if i remember they are same wrist pin diameter

Looks like the FJ1100 is 4 valve?

Quote from: burning1 on December 30, 2011, 01:39:35 AM
I took some measurements of the GS450 rings, to see if I could save some money on after-market options. Here's what I found:


Top ring
Thickness: 1.18mm (manual says 1.17-1.19)
Width: ~2.8mm
Type: Rectangular (Barrel face?)

Middle ring
Width: ~2.82mm
Thickness: ~1.2mm (Manual says 1.17-1.19)
Type: Tapered


Oil rings:
Stack thickness: 2.90mm total
2.22 Ring width
0.46 Ring thickness

2.55 spring width
2.25 spring thickness

Measurements have some margin of error - I didn't have a ball anvil for my micrometer, so the curve of the ring introduces a little error. And there was some surface rust, so again, margin of error for thickness readings.

However, I included manual spec where I could, from the GS500.

Short version, is that there don't appear to be many readily available aftermarket rings for the GS450.

I know this is a totally Heath Robinson approach but it did work on my old CB1100R. Get car rings that are the same diameter and either surface grind the rings or open up the ring grooves on your pistons. Just an idea if you get really desperate.

Just purchased a 1/3HP Flex Shaft machine. I'm going to take a shot at machining the head for clearance.

http://www.wecheer.com/show_prd.php?id=330&lang=en

Quote from: werase643 on October 24, 2011, 05:43:41 PM
http://www.motorcyclespecs.co.za/model/suzu/suzuki_gs400s%2085.htm

i don't think these came to the us...... anybody up nort ever seen one?


I thought the 400X was the 8 V engine

Nah. I don't think I have ever seen one up here. Can't say for certain they weren't imported but I doubt it.

Quote from: burning1 on March 09, 2012, 11:04:33 AM
Just purchased a 1/3HP Flex Shaft machine. I'm going to take a shot at machining the head for clearance.

http://www.wecheer.com/show_prd.php?id=330&lang=en

Please do report your experience with carving out the head. I've over-bored the GS500 cylinders to accept Wiseco 78mm pistons as was done by Dgyver and others. However the piston crown design has changed over the years and is tremendously larger that the pistons that other riders had used in the past. [Actually, I'm starting to wonder if their pistons were not Wiseco but another make??]

So I'm looking into machining down the pistons AND enlarging the combustion chamber in the head. It appears the valve pockets are fine as-is. I really don't know how much material is too much when it comes to carving up the head however, and I'm a little afraid of really mangling the combustion chamber shape.

Short version: I'll be watching your experience with interest. 

Ahem







http://www.thegsresources.com/_forum/showthread.php?t=172422


1981 GS400LX 8 valve Canadian model.

Stock cylinder block
GR650 sleeves set in
Half of a 78mm JE 1260 piston kit
Custom 355 cam's in the works
Increased combustion chamber
10.5:1
80% done.



I like this thread.