Katana 600 -93

[Farbrorn]

I just bought my first bike, a GSX 600F -93 I thought it was not running as well as it should have. I thought it had to be the carburettors, because it had been sitting for over a year with old fuel and everything. I cleaned the carburettors, and replaced old fuel with fresh in the tank.

And after putting it together again it ran no better, so I took it apart again and this time removed the plugs. And discovered that the plug for cylinder 2 was like brand new. Looked like it had just been installed. Brand new. The other three looked like they've been running rich.

Anyhow, I checked how this could be and when running the starter and looking down the intake and making sure the valves move I saw that the right intake valve don't move. Now, obviously I know that cylinder 2 hasn't been running for a while. How can the be, the engine ran fine. But a little tired, no strange sound. It sounded healthy, started easily and no leaks.

Is there some common problem with the head and cam on these bikes?

I've been offered by the dealer to get the engine replaced by a Bandit 600 -04 engine, or he will come and pick up the bike again and have to head on the old bike fixed. We're still negotiating on what will be the best.

Just asking what could have caused, and what the probable fix would be.
I know that the head must removed anyhow, thats for sure. Could a spring have gone? And I guess the exhaust valves on that same cylinder must be dead. Because otherwise the bike would have worked, even with one intake valve out of service. Why only one cylinder. I don't get it.
It should have sounded terrible, spinns like a kitten. But gives a "poff" sound sometimes. Guess its the cylinder 2 firing randomly sometimes when fuel builds up.

Any input on this matter is welcome, thanks!

/Esa

[The CyberPoet]

Re: Katana 600 -93

Valves fail when they aren't adjusted correctly or they go without adjustment too long, come out of the adjustment zone and subsequently bend or snap (if they snap, they usually snap off their tips). Additionally, carbon build-up on the inside of the valve face or piston can act as a hammer, with the piston raising into the valve as a result of the loss of clearance -- but it would have to be a very significant amount of carbon do this in the traditional Kat engine.

The two other reasons are:
(A) Cam chain slop due to a bad cam chain tensioner. This is actually a fairly common issue (bad cam chain tensioner), usually the result of using cheap or incorrectly rated oils under harsh conditions, where the oil forms deposits and those deposits gum up the cam tensioner spring. As the chain slops, it exerts excess forces on the cam itself, and that in turn can lead to cam-run-out issues (followed by valve clearance issues causing valves to bend or snap).

(B) Cam bearing run-out issues, again usually due to cheap or incorrectly rated oils under harsh conditions. The cam bearings, when operating as they should be, are effectively supported on a spinning layer of oil and the bearings themselves aren't doing the work except at start-up. If the oil pressure drops too far, or the oil is too thin (such as by being contaminated by gasoline), the bearings have to take over the work again, and can easily wear beyond their permissible amounts. This in turn again lets the cam run sloppy and can result in the same valve issues.

Like I said, while the cam chain tensioner issue is a known issue that commonly crops up on the pre-98 Kats (and may start cropping up on the 98+ models as they age as well), the other issues aren't common.

Best of Luck!
=-= The CyberPoet

[The CyberPoet]

Other thoughts:

If the bike hadn't run for the past year before you bought it, this may well be why.

The Bandit 600 engine is cam'd differently than the Kat engine, so an engine swap to a Bandit will give you more torque down low but less top-end. It's the only significant difference between the Kat and Bandit engines for that year.

Q: Did you buy it from the dealership, and are they covering the repair?

Cheers,
=-= The CyberPoet

[Farbrorn]

Re: Katana 600 -93

CyberPoet, thanks for the good answer.

only way now is to remove the head and have it checked.

And yes, I bought from a dealer. So he promised he would get this fixed for me, either he will come to me and pick it up with a truck and having it fixed. Or, I could maybe get a replacement engine from a wrecked bandit 04, but he said he would have to check out the bandit engine first. So there are no damage to it. The deal sounds good to me, only setback it that I have to do the switch myself.

I've read in the forum that it should be somewhat straight forward to replace to a bandit engine. Only replacement should be engine and oil cooler. The rest stays from the old engine.

But one question everyone seems to miss when I ask if the bandit exhaust will also fit a kat without modifications?

Thanks!

[Farbrorn]

By the way, I would feel better if I could replace the carbs to the new ones from the bandit -04.. but I've read that the TPS will/can cause a problem.

Isn't the TPS just a sensor on the carbs, and if I don't hook it up wouldnt it run as well without it, even that its there?

[SweetLou]

Dude, if you got this from a dealer, go with the new bandit engine!!!

You will love it, and be getting something newer and better out of the deal!!!

[Farbrorn]

Dude, if you got this from a dealer, go with the new bandit engine!!!

You will love it, and be getting something newer and better out of the deal!!!

I'm thinking about that option, sounds like I have the most to gain do get the engine. Instead of getting the existing fixed. But, I do not know yet if the replacement bandit engine is in good condition. It could have taken damage because its from a wrecked bike.

[The CyberPoet]

By the way, I would feel better if I could replace the carbs to the new ones from the bandit -04.. but I've read that the TPS will/can cause a problem.

Isn't the TPS just a sensor on the carbs, and if I don't hook it up wouldnt it run as well without it, even that its there?

Since you are switching both engine generation to the new generation version & platforms (to something cam'd differently), you need the CDI and the related electrical wiring (coils, etc) for the new Bandit engine... in which case, the TPS will come along as well and plug into the CDI. If you just wanted to use late model kat carbs on an early market kat, you'd simply leave the TPS disconnected (or remove it).

The headers from the old bike will fit, but will come down further; the bandit exhaust should fit without issue, but you may have to dremel out a bit of the under-fairing to clear if it's not the same dimensions as the Kat exhaust (I would expect it to be though).

The only questions now are:
(A) What did you pay for the '93?
(B) Why would you have to do the work?

Cheers
=-= The CyberPoet

[The CyberPoet]

Dude, if you got this from a dealer, go with the new bandit engine!!!

You will love it, and be getting something newer and better out of the deal!!!

I'm thinking about that option, sounds like I have the most to gain do get the engine. Instead of getting the existing fixed. But, I do not know yet if the replacement bandit engine is in good condition. It could have taken damage because its from a wrecked bike.

Because of the frame shape and the way most riders go down, the odds of the Kat/Bandit engines being damaged in any serious way is virtually zero unless the front forks sheared... a quick check of the exterior of the block should answer what shape it's in.

Cheers
=-= The CyberPoet

[Farbrorn]

I just talked to the dealer, he will be sending someone to pick up the bike and have the head fixed. Bacause the bandit -04 engine had damage to its right side. The dealer didnt want to risk getting new parts to the engine and then shipping it to me and finding out something else is wrong with it.

Guess its for the best, I get the bike fixed without having to do much.