1982 GS450E Scrambler-ish to Cafe-ish


Zuk's Rock!
I got the new bump stop installed last night along with the rearsets.

Aside from adjusting the levers everything's good to go, just can't test ride until I sort the speedo out.

https://flic.kr/p/2i1vcJz]Untitled[/url] by https://www.flickr.com/photos/89703844@N08/]starpoint73[/url], on Flickr

https://flic.kr/p/2i1sPyi]Untitled[/url] by https://www.flickr.com/photos/89703844@N08/]starpoint73[/url], on Flickr

https://flic.kr/p/2i1vcKr]Untitled[/url] by https://www.flickr.com/photos/89703844@N08/]starpoint73[/url], on Flickr


Cool build so far.. I have a GS450T sitting in my garage with a bad lower end that I refuse to tear into until my current project (Yamaha XS400) is on the road.. But reading this thread makes me wanna tear into it haha


Zuk's Rock!
Cheers! You can always have two on the go right? :cool: If the lower end is bad you can always just swap it out for a GS500 and just use the 450 head. I understand it's pretty straight forward, although the shift pattern will be reversed as the GS500's have no shift linkage. That should be an easy fix adding a linkage though.

Picked the speedo up yesterday and it does indeed appear to be a quality piece of kit.

I was hoping I could simply swap the Acewell out and use the existing dash and mount but no go. The one good thing with a digital gauge is that you're not really limited with placement and can extend wires if need be. With a mechanical gauge the length of the cable is the limiting factor.

It should be on the left, but the clutch cable would interfere with the speedo drive, so it has to go on the right, and the cable's just long enough to reach.

I'll have to revisit the bracket situation when I have some more time but at least it's useable where it is.

I haven't hooked the idiot lights up yet, ran out of time last night just getting the position right.

https://flic.kr/p/2i2mBK7]Untitled[/url] by https://www.flickr.com/photos/89703844@N08/]starpoint73[/url], on Flickr


Zuk's Rock!
Got the idiot lights all hooked up Friday and got a quick test ride in yesterday finally to check out the rearsets and see how accurate the speedo is. According to the GPS speedo app on my phone the speedo is pretty spot on for accuracy, and the rearsets are in a real good position, just needed to tweak the lever positions a touch to be spot on. I'm heading out for a bit of a twisty ride this morning so I'll see how it all goes!

One thing I definitely miss is a tacho, so I'm eyeing off a GS500 tacho as they're electronically driven meaning I should be able to use the signal from the coil like I did with the Acewell.


Zuk's Rock!
Well it's official, the 450 is fun again!

Had a short ride up a local mountain to meet a mate for coffee yesterday and it was a blast. The clubmans and rearsets make it quite comfortable and the speedo does the job nicely also.

Forgot to get a photo up the top but it's fun for me seeing my little old ratty 450 parked amongst the modern sports bikes :D

I definitely need to change the front mudguard out though, the dirt bike guard on there is way out of place, so I broke out the stock mudguard last night and figured out where it needs to be cut down. Not sure how soon I'll get to do this though as it's going to be quite noisy with the angle grinder. Don't worry, it's got some road rash and is a bit bent in places so I'm not molesting unobtanium.

Untitled by starpoint73, on Flickr


Zuk's Rock!
Happy New Year all! First post for 2020 is a good one for me :D

I hadn't done any more on the 450 as I've been spending my time off doing a serious garage tidy. This made enough room for a new workbench to do all my bending, drilling, cutting, etc.

Relocating the bench grinder also allows enough room to park both the 450 and Kat side by side.

https://flic.kr/p/2i7Knje]Untitled[/url] by https://www.flickr.com/photos/89703844@N08/]starpoint73[/url], on Flickr

As a result, yesterday I got to cut the front mudguard down. I ended up using a metal cutting blade in the jigsaw which made the cutting nice and quick and let me get close to the end result without having to spend ages cleaning up on the bench grinder.

Then I give it and the rusty headlight bucket the satin black treatment.

I got as much of the loose crappy chrome plating as I could off the headlight bucket with a wire wheel then scuffed up the chrome surfaces with some 120 grit wet and dry. Self etching primer then went on along with the satin black, just aerosol acrylic for the moment.

https://flic.kr/p/2i7FQWw]Untitled[/url] by https://www.flickr.com/photos/89703844@N08/]starpoint73[/url], on Flickr

https://flic.kr/p/2i7Jkww]Untitled[/url] by https://www.flickr.com/photos/89703844@N08/]starpoint73[/url], on Flickr

The acrylic takes 24 hours to fully cure so I should be able to get it reassembled this afternoon or evening.


Zuk's Rock!
I picked up a GS500 tacho on Thursday to use on the 450 but when I went to test it I discovered my ignition key wouldn't turn in the barrel. It was getting a bit stiff lately so not really surprised it stopped functioning.

I dismantled it to find three different issues, and it's a wonder it was working at all! The spring holding the little door stopping crap from getting in is broken which I guessed was the case quite some time ago, and of course the graphite I've put in over the years has turned to muck when combined with water and whatever getting in. The third wafer is bent way out of shape and there's no way it was moving at all, and the remaining wafers seem to be worn enough that they don't retract fully.

I'll shuffle the wafers I have around to get the best match I can for the key then I'll have to do a bit of filing on any that don't quite retract enough. Should definitely be fixable though.

https://flic.kr/p/2i9yCuD]Untitled[/url] by https://www.flickr.com/photos/89703844@N08/]starpoint73[/url], on Flickr


Zuk's Rock!
Well a bit of shuffling, a bit of filing, and the switch is back in action again, yay!

Now on to figuring out what to do about mounting the GS500 tacho...


Zuk's Rock!
Well I finally got it out for a decent ride yesterday after the changes so far.

Definitely more enjoyable to ride again and I had a blast, although encountered a couple of issues.

First one's a simple fix... my rear number plate had started to crack from vibration likely due to the weight of the reflector bolted to the bottom of it, and yesterday my favourite bit of twisty road was the final straw. At the top I discovered it had broken completely and was only being held in place by the height of the LED bolts I use for it. Ooops! It's cable tied on now temporarily.

The other is going to be a bit more effort to fix... essentially I have no top end power. Not having ridden beyond 70 to 80kph since May last year and only commuting, I've not picked up I have an obvious issue once the revs get up and the throttle is open. It sounds and feels like it's way too rich once I open it right up. I essentially had little to no top end in the faster sections yesterday, and it wouldn't even hold 100kph up a hill which it used to do with no fuss at all.

I guess it's time to look into putting an O2 sensor bung in the pipe finally and being a bit more accurate on figuring out the fueling.

I've never successfully removed the pipes myself yet so it won't be an immediate thing but I'll need to tackle that soon, and probably at the same time I should attempt to do something about the header dent and probably some VHT flameproof paint as well.

https://flic.kr/p/2idwDrY]Untitled[/url] by https://www.flickr.com/photos/89703844@N08/]starpoint73[/url], on Flickr


Zuk's Rock!
I decided to check the compression last night given the lack of top end and the results weren't good.

Number one has 120 PSI, number two only 100 PSI. Going by the manual 100 PSI is the service limit, but they should be 130 - 170 PSI, and if both cylinders measure under 130 PSI it's time for an overhaul.

So that sort of puts a bit of a damper on the refresh, at least I can still commute on it as it is for a while.

I've been contemplating the GS500 cylinder and piston swap for a while so something like that might be a way forward, but there's no budget for that for quite some time yet at this stage.

I'll still get the GS500 tacho on though as that'll be needed whatever I do.


Well-Known Member
Hot or cold? WOT? Valves in Spec? If no to any of those redo. Hot engine. WOT or carbs off. If valves are tight at all you'll get bad numbers. My cx500 was parked for poor running. PO didnt do valves. I had 100 on left 150 on right. Checked valves. Left intake was tight by just a smidge. Set it to spec and fot 150 and 151. Then finished bike and did warm engine and fot 170 each side.


Zuk's Rock!
I'd say warm rather than hot, was about 3 hours after I got home from work, so should be good enough temperature for testing. Held the throttle at WOT to test also.

As for the valves, definitely something I need to check which will be during the next service in a couple of weeks. I've been running the valve clearances at the open end of the specification and they haven't closed up measurably for a few services, so to be honest I'll be surprised if they're the cause. However I will definitely be validating that as I check clearances every service.


Well-Known Member
Ok glad you did all that, hate for someone to tear down a top end and find out it wasnt worn rings. A leak down test for a bad valve would be good too before you tear it down


Active Member
We used an 82 GS450E as one of our WERA race bikes. Mostly ran in the endurance races and it was stock with the exception of different bars and some carb work. Very dependable and actually pretty quick. It helped secure a national Lightweight Superbike title for the team.


Zuk's Rock!
Yeah these are definitely good bikes! When it was running well I had no issues having fun with the "big boys" on their 1100+ Kats in the tight twisty stuff on our favourite roads, although of course as soon as horsepower comes into play things change :D

I find it a fun little bike to ride, even more so now with the clubmans and rearsets on it, just need to get some power back again.

Cheers for the oil tip Maritime, will do that for sure.

Also probably should've put some back story on the history of the motor... I rebuilt this as the "scrambler" finishing at the end of 2011. I rebuilt the motor as part of this, but it was my very first time doing so and while I can't remember exactly how I verified things like the piston and cylinder spec's I most definitely determined they were "in spec" and therefore simply had the cylinders honed and put new rings in. For the top end, I had the valves faced and tipped then lapped them in to the valve seats. Thinking about it now, I can guarantee a lot more effort should have gone into that process with some more expert eyes than mine on those things.

The ironic part? I rebuilt the motor due to a perceived gearbox issue as I really had to force the shifts into 5th and 6th or it would drop back to the previous gear. The solution to that was actually replacing the external gear linkage for the shift pedal as the heim joints were flogged out causing it not to engage the next gear easily... the things we do to ourselves as complete amateurs...

I shall check things out during the service and see what transpires from there.


Zuk's Rock!
I got the service done yesterday, standard oil/filter change and check valve clearances and so forth.

The only shim needing changing was number 2 inlet as last time I'm guessing I got the clearance a bit wrong as it was way out of spec (over 0.10mm) and had to go up a shim to bring the clearance back down to 0.08mm. All the other three were good.

There's no way too much clearance would lead to low compression though.

I looked down each spark plug hole as best I could with the valves open and the faces looked clean, no significant carbon build up I could see and same with the top of the pistons. Of course I can only see a small section of each that way so it's certainly not a guarantee that the valves are good.

I did a cold compression test and got number 1 with 140 PSI and number 2 with 150 PSI.

Took it for about a 20 minute test ride and did a hot compression test getting number 1 with 135 PSI and number two with 140 PSI.

Now I'm really confused! I did what I could in those 20 minutes to get the throttle open and revs up as much as possible and every time it felt strong, no drop of power like happened when the compression measured low. I'm guessing I have to get the engine hotter again to test this, then stick a bit of oil in to see if it's likely to be rings or head.

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