GS500E Four cylinder

[SteveXFR]

Hi. I'm looking at buying a 1982 GS500E four cylinder. It seems like it's quite a rare model and info isn't easy to find. 

As far as I can find, it was based on the 550 and only sold in a few countries. 

Can anyone point me at a good source of info for this bike? One thing I'm wondering is what the differences are between the 500 and 550? Would it be easy to convert it to 550 spec?

[DAZ]

Quick Google came up with wiki saying basically what you already know that it's a sleeved down 550 with smaller carbs for markets which had specific rules and regulations, I would guess that a complete 550 top end would fit if your current set up is unserviceable but not sure the performance increases would justify the cost for me , the oil cooled 600-1200 do fit in the 550 frame and if you want a big upgrade to the performance then that is the best bang for your buck 

Edit: it maybe that the GS 650 top end is also suitable for the original engine, maybe check the base gaskets part numbers to see if the 500/550/650 use the same gasket ?

Edited July 18 by DAZ
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[SteveXFR]

Thanks Daz.

I want to keep to upgrades of that period and keep it looking original so won't go for the oil cooled engine. 

I'm finding conflicting info on the performance difference between 500 & 550. some sources suggest it's around 5hp, others suggest around 20hp. It's not currently running so I have no idea what it goes like. If it's a 20hp difference, then I'll definitely go for the 550 conversion

[DAZ]

@SteveXFR if you want to keep it original looking then I'd try to source the gs650 /650 kat top end which is actually 673cc so a pretty good boost, especially to the torque. I'm pretty sure it fits and I seem to think (though I maybe wrong) that @wraith built such a beastie for Mrs W , way back so he might have some word's of wisdom for you 

[SteveXFR]

I've looked up the cylinder base gaskets. The GS550 part is the same as the GS500 but the 650 has a different part number and is visibly different. 

[Poldark]

In the US we had for two years (81-82) a GS650E.  Chain drive, performance heads, 673cc.  The engine will drop straight into a GS550 frame.  There is also a conversion mentioned above.  It's been discussed on this forum in the past.