GS425 - Potential Project

[wots]

I may be able to obtain a GS425 quite cheaply. Been off road for a long time, but dry stored. Anyway, I'm fairly certain this will be leaded fuel only, how difficult (and is it possible) to convert to unleaded. Head swap for something else that's compatible?

It's just one of many things to consider, but was curious at this stage.
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Currently: Yamaha DT 125 LC2,Repsol Fireblade, and Bumblebee MSX 125

[bezzabsa]

It'll run on unleaded as it is, most Jap bikes from early 70's took unleaded as standard!!!!

[nowhere.elysium]

It should be fine on unleaded. What year is it? The Japanese have been making their engines unleaded-compliant for quite some time; I believe they started in the early to mid 70s, although I can't find an exact date.

What sort of condition is the bike in? I've just finished getting my '83 GS650 on the road, and it was a pig of a job, at times. The electrics were a particular challenge.

From what I remember offhand, the GS425 was the predecessor to the 450, which subsequently became the 500 which is still around today. Although Suzuki was investing a bit more time and money into the finish of their bikes back then, I'd still keep a close eye on any steel bits, in case it gets a dose of the tinworm. The engine casings will fur up at the drop of a hat, but it's nothing seriously harmful.
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'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[wots]

[nowhere.elysium]

[wots]

[nowhere.elysium]

OK. Well, according to your profile, you're in South London, right? I'm based in East London, and have some experience of particularly recalcitrant elderly Suzukis, so I'm happy to lend a hand if you need it.

Based on your guess as to the registration, it'll be somewhere between 1978-80 (at a guess), so it should be happy with unleaded regardless. Most of the parts on this era of bikes are mechanically simple to work on, although I'm warning you in advance about any rubber parts; they may not have perished, but they will have transmuted into granite. As for the electrics, brace yourself for some fun times.

This might be of some interest to you.
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'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[wots]

Electrics I can deal with, good experience with this in various fields. It's the Mechanics I'll need to get to grips with.
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Currently: Yamaha DT 125 LC2,Repsol Fireblade, and Bumblebee MSX 125

[nowhere.elysium]

It won't follow any common sense rules, I promise you

The mechanical side won't be too challenging; there's nothing overly complex in them, although there were some questionable design decisions - silly things like the carb linkages not liking the English weather very much. Nothing insurmountable, though.
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'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[wots]

Good first project bike then?
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Currently: Yamaha DT 125 LC2,Repsol Fireblade, and Bumblebee MSX 125

[nowhere.elysium]

Provided you don't mind swallowing the cost of parts, yes. They shouldn't be too bad, but check the availability of electrical components (or be prepared to build your own electrical system from scratch), and I found that seats, exhausts, tanks and bodywork were the pricey bits. If they're in good nick, then you're laughing.

Take a look under the seat, though; if it's rusted through, budget for a new one. There's a guy in Germany that I bought a brand new seat for my 650 from; £160, but worth it, given the originals are unavailable.

Be prepared to buy things from the US, but only if you have no other choice. Their postal system is dog slow, but old Suzis seem to be more popular over there.
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'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[wots]

I noticed when looking at parts, was checking forks, that a lot of parts were in the US.

What models are (to some degree) interchangeable with parts then?
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Currently: Yamaha DT 125 LC2,Repsol Fireblade, and Bumblebee MSX 125

[nowhere.elysium]

Also meant to add that CMSNL have got a great parts fiche library, and Robinson's Foundry is the place to order OEM parts from; CMSNL sometimes has marginally better prices, but Robinson's will deliver much faster.
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'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[nowhere.elysium]

[Bezzer]

You'll find the 425 has a lot more in common with the earlier 400 motors than the later 450 and 500s as it was basically a bored out 400. The 400 and 425 had roller bearing big ends and a longer stroke compared to the later plain bearings and bigger bore/shorter stroke of the 450 and 500. You might have more luck with later cycle parts though.
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I used to be indecisive but now I'm not quite so sure.

[wots]

Just downloaded that Manual, brilliant will have a look through later. Also looking through your thread for you 650
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Currently: Yamaha DT 125 LC2,Repsol Fireblade, and Bumblebee MSX 125

[nowhere.elysium]

Heh. Well, I hope the manual's useful, and that the thread's a worthwhile read. I've got a Clymer manual for my 650, and it's surprisingly good. I'd still recommend getting hold of an original Suzuki service manual if you can, though; they tend to have very good exploded diagrams, which can be a real sanity saver at times.
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'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project