How many have changed their camshaft

[OBrian-DK]

Hi there.

A question from overseas.

I'm the owner of a 93 600 kat with aprox. 50.000 miles on it, and now i am wondering how many miles yours have run.

In Denmark many people tells me that i have to get my cams checked and replaced because of some issues with a weak making of the cam's. Something about the surface loosens and then destroys the rockers.
Is that true or is it only on the 750 Kats the problem exists.

I have just bought the bike this year and was not planning for the adjusting until winter, so i have not lifted the valvecover to check it yet.

btw. sorry for my grammars and spelling. I'm danish. (and not the cake )

[steves]

Cam's aren't too hard to do. Just pay close attention when you are lining them up.

I think you may be asking about valve adjustments though?

[arsenic]

valve adjustment = important. Changing cams - unless your upgrading to GSXR cams, there is no reason to change them. A 93 Katana 600 is shim type valve adjustments thats not a DIY job.

[OBrian-DK]

No its not the valve adjustment i'm asking for. that i know every 4000 miles.
But i have heard that the cam's on the katanas is a weak "spot"
They will wear out very fast, especially on pre 98.
But my question is: have anyone in here have their camshafts changed because of excessive wear and tear?? and at what milage???

[arsenic]

I've never heard of that as a problem. I can't speak from expirence, but I've never heard of that being done.

[steves]

I've seen some people who never had the adjustment done have some messed up cams...

[Newbie2it]

Well I can speak from experience regarding the 93 750. Mine had 15k on it when I discovered the issue. The lobe did become pitted and did eat into the rocker arm. I had to replace my cam and rocker. Suzuki said there were some known issues with the hardness plating on the lobes of the cam. The hardened steel where the rocker rides actually comes off in spots leaving the rough cast of the cam below it exposed.

Replacement of the cam is not hard, Just a bit involved. However, my one single suggestion, one I had to learn the hard way. Just replace the bolts that hold the cam caps down instead of reusing them. Its not worth snapping one off due to years of stress. If you find you do have to replace yours. Make sure you follow the diagrams regarding the cam caps and the directions they face. Also make sure to replace the cam idler pulley with the arrow facing the front of the engine. Since you'll have to reset the cam chain tensioner, might as well replace the cam tensioner spring. Its only a few bucks from the dealer. Follow the manual for proper alignment of the cam chain and make sure your on the 21st pin. Readjust your valves and put the lid back on.

One other note, If you had to go this far, check the cam chain guide for wear, theres actually three, but one can come out from the top, the second is held in place by a phillips screw on the front of the block down further in the head, but if you drop that one, theres going to be a problem, the third comes up from the bottom and that you cant get to without splitting the case.

Hopefully your cams ok and you dont have to sweat it.

[stevens4life2]

I'm just wondering, what does changing the cam do anyways?...lets say i changed to a gsx-r cam... what would be the performance difference?

[The CyberPoet]

I'm inclined to believe that the cams get eaten up if you ignore a bad cam chain tensioner, which is a much simpler (and cheap) fix -- I'll have a pre-98 kit with the spring & gaskets this winter for sale in my maint items for probably under $20, which will fix it (won't correct eaten-up cams, but hopefully you'll do this before the cams bite you).
Unfortunately, the cam-chain tensioner spring does get weak and the tensioner button can easily get blocked by sludge-gunk if you're not using a high detergent oil (or overheat the engine or fail to change it regularly enough). And if the tensioner gets screwed up, it will let your cams get a few degrees out from where it should be at certain RPM's, allowing the valves tappets to slap the cams pretty hard.

Easy way to check the pre-98 cam tensioner spring -- upper is new, lower is bad:


Cheers,
=-= The CyberPoet

[crazypj]

The early 750's (GSX-F & GSX-R) had some issues with hardening flaking off and/or pitting. I think it was only 89~90. Probably had same company who 'hardened' cams for the VF750 Honda do them
PJ

[OBrian-DK]

Hey CyberPoet. I could be interested in at spring and the gaskets for my tensioner. What will i cost to send abroard to Denmark