Carb vs EFI 650 + ECU Swap

[Jacob]

Bike Model = : 2010 gt650r

I recently got to ride a carby model 650 and man it’s night and day more powerful than my efi 650. I can’t find any solid information on stock power figures but the carby bike got to 110kmh in 2nd like it was nothing and in the EFI it got to 95kmh in 2nd and took a few secconds to get there. It really felt like a rocket in comparison. I’d twist the EFI throttle and still want more…Has anyone else experienced this or is my EFI just down on power?

 

Continuing on from that I know the early ECUs can’t be tuned but the later Delphi ones can. Would it be possible to get all loom, ecu and dash from a facelift 650 model and slap it on my 2010 model? Then get it flash tuned and awaken some extra power I feel like it’s missing?

[♠️ M77]

Hmmm, your 650 should have a Japan Mitsubishi ECU  (if it says 2008-2010 on the chassis) , it is not a bad ECU  , but  any EFI will be a little slower for emission laws in certain countries, so Hyosung just used a universal map of their own , so it behaves the same way whatever country it is sold to

Have tried this first (use the service manual on the forum for tutorials),

• compression check
• valve clearances
• TPS check
• Fuel Pump can’t be checked easily but check strainer isn’t gunked up  or if the motor sounds weaker,  get a new pump, it helps a LOT.
• Pour injector cleaner for bikes inside your fuel tank  (all of it) => Ride until the tank is low on fuel, so the cleaner mixed with fuel can try to “soft-clean” your fuel system so to speak,  maybe injectors could just simply need a clean.   Worst case scenario (brand NEW injectors will make the bike alive again)

Report back with your figures?

Check the last owner didn’t add performance filters or upgraded his jets or did some kind of tuning or change sprockets to alter gearing to make you feel like its faster than your EFi.

EFi is supposed to be more snappier on throttle than a carby one in general.

But ….. a properly tuned carb model will have a small edge of a stock EFi.

Unless you’re also smart or know someone that lives inside DELPHI ECU’s  , you can ask them to tune your ECU if it says DELPHI with the harness etc ,  there is a risk, a small mistake can render the ECU dead completely.

So check your bike with the manual & do the cleaning suggestion ,  then see how you feel  and weigh your thoughts on that.

Keep us posted!

[Jacob]

Hmm okay, I’ll definitely have to work my way through that list. I can say when I first got the bike it ran pretty rough and slow. Almost completely cutting out one cylinder. It did have really old fuel in it but after I put fresh fuel in and some injector cleaner it brought it up to where it is now. I’ve still got more injector cleaner so I’ll run the rest of that through and see if it helps. The pump sounds strong but a 25 year \ 25,000km old pump probably could do with a change. New injectors probably isn’t a bad idea either.

I’ll report back with all my findings after I test everything.

 

I did pull apart the carbs to clean them, I didn’t really pay attention to the jet sizings (probably should have) but they looked old enough to be original. (44,000km bike) The air filter was new but definitely not a performance one. I assume stock gearing aswell. As the previous owner really kept this bike original. I unfortunately just sold this bike so can’t do any more investigating.

 

My EFI does say 2010 on the chassis, I’m at work atm so can’t remember what ecu I have, the only marking on it I remember is S&T. I will update once I get home. But I do remember reading these ECUs are untunable but the Delphi ones can be flash tuned and some people offer the service. Or I might even look at a power commander to add some extra oomph. The only “performance” mod on my EFI is a moshimoto muffler. But I’ll cross that bridge if the service and checks don’t bring the power up to what I’m happy with.

Definitely will keep everyone posted

[Author]

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