For Those With the 650 block on a 550 -

[klr]

I'm considering this mod and have a couple of questions:

Any long-term reports? How are they holding up?

What is the vibration like - more, less, no change? I assume that the 650 pistons are heavier than the 550 so I wondered what that would do to the level of vibration.

Thanks.

[tkent02]

I am going to look for some lighter wrist pins, the whole thing should be balanced the same if I can find the right weight pins.

[VinciMMA]

tkent02! Did you perform this mod to your 550?? I created a thread asking this same question with no response

Was it just a drop in and bolt on? Anything need to be modified? Did you use the 650 carbs or 550s? Do they both share the same diameter exhaust ports, so I could use my custom pipes from my 550?

Please as many details as possible or a link you posted about the process would be MUCH MUCH appriciated!!

[tkent02]

tkent02! Did you perform this mod to your 550?? I created a thread asking this same question with no response

Was it just a drop in and bolt on? Anything need to be modified? Did you use the 650 carbs or 550s? Do they both share the same diameter exhaust ports, so I could use my custom pipes from my 550?

Please as many details as possible or a link you posted about the process would be MUCH MUCH appriciated!!

Actually, I just bought the bike a few days ago, have done nothing but strip the paint off the gas tank. I am trying to gather parts to do this 650 top end, since the head is off of this one anyway.
Suzuki Don is just finishing his up, there are a couple on this forum who have done it previously.
One did a thorough write up about it a few years ago. Last year sometime I asked him how it held up, he said it was fast and running well.

I can't remember who it was just now.

Do a search, you can find it.

Tom

[Suzuki_Don]

tkent02! Did you perform this mod to your 550?? I created a thread asking this same question with no response

Was it just a drop in and bolt on? Anything need to be modified? Did you use the 650 carbs or 550s? Do they both share the same diameter exhaust ports, so I could use my custom pipes from my 550?

Please as many details as possible or a link you posted about the process would be MUCH MUCH appriciated!!

Read my write up in the TIPS Section on the exhaust modification to fit 550 headers to 650 head.

You need to grind parts of the inner crankcase to allow clearance for the 650 cylinder spigots. It can be done without removing motor from frame and without splitting the crankcases, although I did both.

Do a search on threads stated by me and you will pick up some extra info.

Then ask specific questions.

[Suzuki_Don]

tkent02! Did you use the 650 carbs or 550s? !!

With the 650 head you will need to use the CV type carbs -- BS32SS. Either 550 or 650 Cv carbs can be used, but you will need to rejet if you use the 550 carbs. Simpler to get a cheap set of 650 carbs and do the dip and "O" ring thing. New boots, etc.

If you have the earlier 550 with VM type carbs, they will not work, different size ports.

[VinciMMA]

Suzuki Don, Thank you!! I will search your threads and read about it...I'm really wanting to do this mod it would just take my bike to the next level. She's already pretty darn fast...out running some newer 650s but of course I want more !! I ride pretty modest for what the bike is but I like knowing that if I want to I can smoke most 650s off the line..so after researching more and doing the mod I'm sure she would speed right past some 800cc at least...my bike only weights 370lbs...heres a pic

http://s113.photobucket.com/albums/n225/vinniedis300/?action=view&current=IMG_1253.jpg

http://s113.photobucket.com/albums/n225/vinniedis300/?action=view&current=IMG_1254.jpg

[Suzuki_Don]

Vinnie, I've worked out a 52% increase in power.

[VinciMMA]

Sweat!!!! The previous owner and I estimate the bike is making around 55-57hp as it currently sits so that is SICK! I want to do it even more now haha of course I'm probably going to wait till winter to do it...planning on a complete strip down, powder coating frame, brackets, wheels, misc parts, repaint engine block and thats basically it..paint work, seat, carb work down my myself so no need to do much at this point. Plus I'm wanting to take it to shows/out during this very nice weather for spring and summer. But that's crazy if its making 52% more power I'm for sure doing it when I tear her apart this winter. Thanks again!

[klr]

So, back to the vibration issue - has anyone weighed a GS550 and GS650 piston?

I put an oversize forged piston in my KLR650. It was lighter than OEM and vibes went way down.

[VinciMMA]

klr, 650 piston weight should be 3.2lbs i believe according to source, that being local Suzuki shop I imagine the 550 is slightly less...though don't know if youre going with an aftermarket piston or whatever they market as "high performance" I'm sure aftermarket would be lighter which more than likely = more vibration

[MrZufall]

Thanks for the info guys! My cuz pointed this out to me. I really like my bike, but the thought has crossed my mind that a bit bigger would be awesome- this is DEFINENTLY going to be an up and coming project for me!