I'm going to up the rev limit on GSXR1000K3 after the good advice and help from you guys on here but after asking around and speaking to the engine tuning shop that will be doing the work it seems you need to replace at least the valve springs and possibly the cotters as well. I知 100% going to change the springs the question is which ones. Obviously the most expensive and correct way would be to go down the Yoshi springs route but the engine tuning shop said no need they build 175bhp+ 13,100 rpm bikes with GSXR600 springs and recommended putting these in mine. On talking about upping the revs limit on another thread a couple of you guys recommended the GSXR750 springs so I知 a bit confused. Obviously the 600 has a higher rev ceiling so are they possibly even harder than the 750 springs and better? Let me know your opinion as at the moment I知 going with what the tuning company are telling me which is the 600 ones. Thanks.

Use the 750. I was under the impression that Yosh got out of the valve spring business.

Jay

their are several posts which say 600 and 1000 are 32 lb springs only 750 springs are 40lb and will keep the valves from floating at high high rpm.s also the keepers and retainers have to be perfect because of added stress with larger cams. read some old posts on cams and such

How many 750 valve springs would I need to do this mod?

Zilla said:
How many 750 valve springs would I need to do this mod?



Wild guess: one for each valve (16) http://www.gixxer.com/forums/images/graemlins/smirk.gif

Just searching on the old threads on cams, valve springs and cotters and no one ever mentions the retainers. Is everyone taking it for granted that these are being replaced at the same time for APE or equivalent Titanium ones or are the standard ones good enough when you致e had cams put in and or upped the revs?
I知 only upping the revs and am having the 750 springs put in do I really need to do the cotters and retainers as well if they are in good shape? I知 not looking to do cams in the future.