crank shaft swap for 50 more cc

[Guest]

As I understand it the 1985 GS700ES is just the 750 engine with a shorter stroke. would I be able to install a 1984 GS750 crank to bump mine to 750cc? Or am I way off base here? what else would I need if it will work? is this a huge mistake/waste of time? Let me know what you all think.

[blowerbike]

grab you an 83 750E/ES engine and pop it in.
i'm not sure of the 84 750 you speak of..not in the US anyways.
the 700 production was from 84-86 if i'm not mistaken.

[Danaconda7]

Oh, I did not know that the 700 had that many years of production. But more to the point i cant just swap the cranks?

[Nessism]

Go here and check the various part numbers between the two engines, that will tell you what's different...http://www.alpha-sports.com/suzuki_parts.htm

For one I know the pistons are different. Not sure about interchangeability though.

Overall, swapping the crank isn't worth it for just 50cc. If you have to change the crank for another reason though, you may as well go as large as possible.

[hjfisk]

I have a 83 750, and I don't know but have heard that the 700's actually perform alittle better than the 750, they rev alittle quicker as I understand.

[blowerbike]

Oh, I did not know that the 700 had that many years of production. But more to the point i cant just swap the cranks?

crank/rods/pistons ect..
all depends on rod centers and piston pin location.
there is more difference than just the crank.
parts #'s don't always tell the story.

[Danaconda7]

cool, thanks for all the info.

[rapidray]

Swap in the crank, rods & pistons but use the 700 cams. The cams they put in the 700 were the key to that motor running as good as the 750s it replaced. Ray.

[Danaconda7]

awesome, thanks rapidray.

[hjfisk]

So Ray are you saying a set of 700 cams will wake up a 750?

[postman_pat]

Swap in the crank, rods & pistons but use the 700 cams. The cams they put in the 700 were the key to that motor running as good as the 750s it replaced. Ray.

The stroke on the GS700 is 49.6mm.

The stroke on the GS750 is 53mm.

Would some sort of cylinder spacer be required? Or do the rods take care of that?

[salty_monk]

So Ray are you saying a set of 700 cams will wake up a 750?

Correct... Hotter cams possibly a compression bump from memory.

[Danaconda7]

over all this seems like a good mod. I will have to see if I can track down the parts needed and see what it might cost overall.

[rapidray]

Usually the cheapest to find an 83 750 engine & build a hot rod from the 2. NEW parts would be STUPID expensive!!! Ray.

[Danaconda7]

I will keep my eyes peeled for an 83 750 engine. Thanks for all the advice guys!