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Discussion Starter #1
I ride a 1996 Suzuki Katana 750. I'm probably the only rida that prefer early models over late models. I have an unusual tapping noise emanating from the top of my engine. It kinda started after my clutch went out while riding. I went to change gears one day and accelerated and redlined the engine as the clutch went out. My clutch wasn't worn. When I took it apart, everything simply fell out of the motor. The lock nut literally must have worked its self a loose. When I rebuilt my clutch and started back riding, there was this tapping noise coming from the engine when I rev it up past 3k.

First thing that i did was a valve adjustment, the noise persisted. I then replaced the CCT with a MCT and the noise persisted. I am at a lost of what else it could be beside maybe piston slap and scoring, which I doubt is the case because that usually occurs in high mileage engines, my bike just flipped 23k. Please help guide me to a solution so I can start back riding.

Most have said that these bikes tend to make a lot of engine noise, and I get that, but I am the second owner of this bike and it had 9k on it when I bought it and I guarantee you that it wasn't making this noise. It almost sounds like the noise a bad lifter would make in a car, the higher you rev the engine, the louder the noise gets. :banghead::?:
 

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I'm probably the only rida that prefer early models over late models.

I went to change gears one day and accelerated and redlined the engine as the clutch went out.

I then replaced the CCT with a MCT and the noise persisted.

I am at a lost of what else it could be beside maybe piston slap and scoring, which I doubt is the case because that usually occurs in high mileage engines, my bike just flipped 23k.
Welcome. There are a LOT of riders who like "vintage" bikes......and quite a few on here too.

For future reference, unless you are actually on a racetrack, your first move with the throttle should be just enough to be sure it actually is in the gear that you think it is; after that, pour on the gas if you want.

That incident might have resulted in an over-rev. I know you are trying to talk yourself out of engine damage but I think it is likely.
Could be a spun bearing or a damaged valve.
Whatever it is might never cause a total engine failure.

You need the services of an honest, competent mechanic.

P.S. What is a CCT and MCT ??
 

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You need the services of an honest, competent mechanic.
How would I determine if it's a damaged valve?
How can I check for a bad bearing
See above.
YOU probably can't.
You either need YEARS of experience working on motorcycle engines OR you need to tear the engine down.
You don't qualify for either.

Not trying to be nasty, just honest.
 

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I wonder have you adjusted the valve clearances. This bike will almost certainly have buckets and shims...a special tool is required to depress the bucket to gain access to the shim...I know from experience I had to buy one years ago when I had my 79 GS 750...same engine I believe. It is basically a small 'U' shaped device that slips under the cam shaft and has a lip that presses on the bucket as you rotate it downwards...similar shape to a 'C' spanner.

Sorry just read you already did the valve adjustments...they can be tricky getting the correct shim thickness. I would be tempted to drain the oil and check carefully for any foreign matter....any slivers of metal spell trouble. Does the tapping come from the top end or lower down the cylinders? The cam chain may be beyond adjustment although they tend to make a rattle sound rather than a tapping sound. Possibly recheck your valve clearances?
 

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Discussion Starter #8
yes aussie steve. We double checked the valve clearance per the manual with clearance shims of various thicknesses. I can upload a video with sound of the bike and you guys can be the judge if it's a rattle or a tap, I just know I don't like it and I want it gone. The sound appears to be coming from the top end. At this point the two choices that I'm faced with now is to put it all back together and ride it until it breaks or do a top-end down overhaul for a cool $750.00 plus parts. I prefer the former rather than the latter because I don't readily have that kind of money laying around at the moment until I sale more artwork.
 

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There are other options.
HAVE AN EXPERIENCED MECHANIC LOOK AT IT.
It sounds to me like you are about to make an expensive mistake.
IF the problem is in the bottom end, like a crank bearing, a complete teardown will be required, at about twice the figure you quoted.

You could trade it in too.
 

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yeah i know. I am more than likely just going to ride it until it breaks. That way I will know what it is. I spoke to a licensed mechanic and that's what he told me. supposedly this guy has been a Suzuki mechanic since 1971. I'm putting it back together tonight and a guy from WOW Motorcycles in Marietta GA is going to come by and listen to it with his stethoscope and hopefully he can point me in the right direction.
 

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fingers crossed....hope its as simple as loose bolt or exhaust pipe!
yeah me too although i doubt its the exhaust pipe. That was one of the first thing we check because i had a tapping noise in my zx750f kawi and it turned out to be loose metal rattling inside the crossover chamber. I switch from 4-in-1 to 4-in-2 and after that is when it started. Loose bolt is a possibility. I had that problem last year when all of the oil came spewing out of the valve cover on the freeway none the less(good thing wasn't in a curve when it happened). I thought the head had crack or something. It turned out to be a loose bolt on the head.

I too have my fingers crossed. I will just have to tolerate the noise. My headphones will drown most of it out
i appreciate all you guys input on this topic, thanks a lot.
 

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My headphones will drown most of it out
i appreciate all you guys input on this topic, thanks a lot.
If you do decide to "ride it out" you NEED to be able to hear the noise at least a little so you can tell if it suddenly gets a LOT worse........so you can stop before the engine locks up.
 
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