Repacement carburators or fuel injection

[gregoblv]

I was wondering if anyone tried a different set of carburetors on a GS500? 

Also, I have heard alot of people have wished for a new GS with fuel injection and I would agree, but has anyone tried to setup a FI for one? 

I am rebuilding a 93 into an adventure bike and am looking for possibilities.   

[cWj]

Search around the wide world of the web, but your conclusion about FI will likely be that the expense is better directed at acquiring a bike with FI...

Unless your desire is specifically to gain experience designing and building an FI system,

and it seems like you're more interested in having a bike to ride.



http://suzukigs500efi.blogspot.com/2009/04/salut.html

[lucas]

Cool blog!  Thanks for the link.

I like the summary he gave in post #25:

Because i come to an end (relatively) i want to share more from my experience. First of all, for those who want to create their own EFI, it is not a simple job to do. You need to know , at least, the base of electronics, mechanics, programming controllers and computers. You have to be organized , self motivated and your own teacher. You can find all the information you need on the internet. Also you need 500$ and time.

[cWj]

Somewhere on this forum is a gentleman who worked on doing FI as an engineering degree project. Again, it is a matter of dedicating serious amounts of energy, time, materials, $$$ and know-how. There is no "figured-out method". I don't think I'm hyperbolizing to say it is easier to just cannibalize an FI bike for its tank, engine and brain to graft into the GS.


The ADV conversion has been attacked before with some success. Use our little friend the The Search Box to indulge your dirty GS fantasies. There are at least a couple threads around here somewhere.

And there was somebody (not a forum member) that had one on ebay within the past year, I think.

[gregoblv]

OK, so I am seeing the same info here as I have found elsewhere about the FI. And that is fine. I was just wondering.

How about better carbs? Anyone messed with them or are they good enough that it is not worth the effort and money?

I have not really cared for the CV type carbs since my 69 Honda 350, but I know they work OK. I am concerned about their use at high altitudes. My Honda did not like going up the mountain in Albuquerque and I really don't want it to happen with this one.

Thanks for the info.

[mwe]

there are keihin round slide CR carbs available for the gs...I think 35s if memory serves.  You might also try looking for a set of crs or even fcr's from a triumph and re-rack to fit intake spacing on the gs. 

I have not given it much thought but if i were to do EFI.  I would probably start with the Hyosung gt250r or gt650r tank as I think the gs frame is similar enough that it would fit and the hyosung came with EFI so it should have the fuel pump etc in the tank. Then it is a matter of finding appropriate throttle bodies (again I would probably look to that hyosung as a start since I am already in there for the tank but maybe the triumph would be easier and perhaps even cheaper since there are more of those on the road).  Then hook it all up with a microsquirt program... and bobs your uncle.  I would actually estimate that buying a hyosung tank would probably be the most expensive part of this project but certainly not for the faint of heart.

[mwe]

on a side note...I actually like these carbs.  They are very simple and very well.  You may want to take a ride up that mountain and see how she does first.  If the bike struggles then i would probably look into rejetting to find something that works better.  Also, are you using the stock airbox?

[Big Rich]

Greg, CV carbs are generally considered better for handling extreme conditions (elevation, humidity, and temperature changes). That being said, they are also able to be tuned for such conditions. In the US, the mixture screw is sealed off but that's the main reason it is adjustable. Ever read "Zen and mmotorcycle maintenance"? Robert Peirsig had to swap jets riding up a mountain because his Honda starting running rich.

Now mechanical carbs.... I can't remember a detailed thread here of somebody installing them. There are some options though. Mikuni VM or TM for example, along with CR carbs mentioned earlier. If you decide to go this route, plan ahead: you'll have basically zero jetting info to start with, all the hardware involved  (throttle cable, fuel lines, no more vacuum petcock, no more airbox, etc), and you'll still have to deal with jetting changes at higher elevations.

[krsa2000]

Ecotrons have an EFI system that can be used for the GS.
http://www.ecotrons.com/products/400cc_to_800cc_engine_fuel_injection_kit/
A custom inlet manifold will need to be fabricated.