Hey folks, I recently picked up this bike and am it using it for the occasional F40 race and trackdays. Some of you were extremely helpful last month in aiding me to troubleshoot the source of a few metal shavings in the oil (tranny dogs). I'm onto a new project and was hoping you might share some wisdom from your experience. I have read on a few threads here that this bike is prone to suffering valve train failures that often result from the spring retainers breaking. This thread, in particular, was insightful: http://forums.13x.com/index.php?threads/when-should-you-replace-08-gsxr-suzuki-valves.275868/ With all this in mind, I bought a spare complete cylinder head and was planning to rebuild it with APE titanium retainers and Yosh keepers. For cost reasons, I obviously don't want to replace the valves if I don't have to, so would inspect and measure everything and keep what appears to be in spec (valves and springs). However, I am planning on having the bike properly tuned by a fellow who also builds engines. In speaking to him, he advised me NOT to use the Yoshimura collets with the used valves because the original keepers have likely "worn into" the valves. So, specifically, I'm basically looking for a second opinion on whether to install the new keepers on the old valves, and more generically, am I on the right track with what I'm trying to do? Am I overthinking all this? The bike has 12,500 miles with a fairly unknown track history. Compression is 180-185 across all cylinders and valve clearances were in spec. As always, I appreciate any input. Thanks.
I was mistaken; you are correct. F40 is Superbike. Really, I am just trying to maintain the motor properly and avert a major failure. The goal is reliability. The budget is not unlimited
so the head you got has 12,000 miles? Thats ALOT of miles on titanium valves and all the components. Springs need to be changed at least every season. I did a rebuild of a stock R6 head and it was $2300 all in when you add gaskets and new seats. All new components sourced as cheap as possible. Yes I have a small collection of "usable" ti valves which are pretty much worthless to sell. I would not put them back in an engine thats going to be singing at redline.
Change the valves. If you go to aftermarket retainers polish the tops of the springs on a wet rock before installing them. They are prone to wearing if you don’t.
Replace everything, springs, valves, retainers, cotters. Have a quality valve job done. Or cheap out and wait for something to break and ruin your weekend and the engine.
Thank you gentlemen. That's what I was looking for, advice from seasoned experts. New valves, springs etc. it is.
A wet rock is what is used to sharpen knives. Smoothing the tops of the springs greatly reduses the wear on Titanium retainers. Especially aftermarket ones. Seems like they have bigger issues with it than the OEM stuff.
I didn't know this and had a 250 Moriwaki drop a valve on the 5th race weekend with a newly rebuilt head. I went to oem retainers after that.
This is ridiculously spot on (I just went through this). I wouldn't put in the Yosh collets. I'd replace everything with OEM and get all new valves, springs, seats etc and give the motor a proper valve job. You don't need to do a major port and polish ($$$) or anything like that. Keep it simple. Establish a relationship with a local dealership and use them to buy the parts. Who knows, they may cut you a deal. I've found that working with a dealership has been far more rewarding (for the both of us), than just simply turning to Amazon every time you need something. The dealership I've been working with actually saved me hundreds on my rebuild, as opposed to buying online.
I meant strictly for parts. I wouldn't let anyone at a dealership service anything of mine. Parts only.
Ya nothing like getting your bike back to the pits, starting it up to see what that noise was and a piece of valve comes shooting out.