So I'm trying to work a deal to acquire a 98 GSXR600/750. The bike is a little rough but I'm planning on giving it a street fighter look anyway so that doesn't matter. What does concern me is the engine. Somebody stuffed a 750 into it which would make my street fighter idea even better. But.......... The current owner says it "spit a shim". He started it briefly and yep it's got a very loud tick almost bordering on a knocking sound. The bike is dirt cheap anyway but I'm wondering if it is a "spit shim" would it be really loud like it is , and if it did spit a shim what sorta damage could that have caused? I don't mind having to readjust the valves, he'll if the price is right I wouldn't even mind having to source a new head or having that one fixed if possible. I just don't know if I want or even have the time for a complete rebuild or finding a new engine.
A gixxer is shim under bucket. I'm not certain it can even spit a shim out. Maybe it can. One of the wrenches around here will be a long to say yes or no.
are you running it with the shim out!!?? if so stop....NOW!! my boss had an older gs450(i think)that spit the shim.it shot through the side if the head though,and wouldnt run at all. the local dealer at that time was able to weld the break/hole,but that was a very lucky instance that may not be awarded to you,seeing as it sounds like you are running it,which means you are chewing things/cams/followers up FUBAR. this isnt just a valve adjust now
Thanks Venom, I've never actually opened up a modern engine. (plenty of buell engines) so I guess I should have asked if it was even possible. I'm tempted to over something even lower than the already cheap price and just buy it with the intent that the motor is blown.
aaahh,i dont know gsxr's. he needs to grin and bare it and pull the valve cover off and inspect whats happening in there. dirt cheap bikes can be the most costly sometimes.....
Ummmmm I'm not running it....... The bike was parked on his lift. He fired it for about 2secs to show me it ran..... He'll that may have damaged it more , I don't know, but it ain't like it is being "run".
That bike is a plain 750, with what looks like '96 750 bodywork on it. Hell, I wouldn't be surprised if the whole bike is a '96 not '98. Is it FI? Good luck with a "split shim". How does he even know that's what it is? If he went that far to investigate, why wouldn't he replace the shim when he's there? Expect major motor work.
Well unless my googlefu is not working seems that according to what I found it can't spit a shim....... So decisions.... Gonna offer him $400 and see if he bites.
okay gotcha. even running it quickly is enough to keep tearing up stuff that may have been salvagable though.but if youre going into it open-minded for even a good but cheap chassis,then good find:up:
No it's a 600. Title and vin#s match and title is for a 600. Didn't really matter to me since I'd pull the body work off anyway.
I'm not saying it isn't possible. I'm just unsure since I've seen the mechanism and unclear how the shim could get out from under the bucket. The shim is essentially just a little larger than the shaft diameter of the valve stem and sits in a recessed pocket on the spring that is then covered by a bucket. I'm not sure what mechanical occurrence other than a dropped valve would see the shim being able to escape. My little VFR has the same shim on top the valve spring but it's only held in place by the rocker arm. I can see floating the valves in that set up resulting in the possible escape of the shim.
I believe the 750 is 33E and the 600 is 34E. However, they share the same case and frame (not swingarm or forks), so you have to check the cylinder. Last of the GSXRs with separate cylinders and cases. Look around the cylinder and head for the 34E, I believe it's RH Front corner of the cylinder, lower seam. This is what happens when you drop a valve on a 1998 GSXR600 at 13,500 RPM-ish:
I would say it's more likely a broken valve keeper. I once downshifted when I wanted to upshift on one of these bikes, over revved the crap out of it and thought I blew it up as it immediately lost power, turns out the shim bounced out of it's hole but stayed between the keeper and bucket, popped it back into place and ran another 2 seasons.
Yeah, spitting a shim is a term held over from the over-the-bucket shim days. Something else has to happen for a shim to come out in the under bucket setup. You could be looking at most anything with that noise but I'll bet you a dollar to a donut you aren't going to fix it with a valve shim. Buy it for salvage price, you won't know what it needs until you tear it down.
I was pinned in top gear, slight bend, just standing it up. Clutch in, hand up, coasted into the pits. Not a drop of oil outside the belly pan. Thank you sharkskins! Should be plenty of parts around for these things, plus they are stupid easy to work on. Top end? I have Yosh cam sprockets on stock cams you can have. Valves? I have some of those, too. Valve buckets? Plenty in my garage. Might even have a decent cam chain and a stack of gaskets. Crank? Got you covered. Cases? Pistons? Well, not any more... Ebay is your friend, or let me know if you need anything. Happy to provide if you pay shipping.
