Valves tapping/knocking

[6evil9]

Hi everyone
bike: Suzuki GSF250 30,000ks

has a problem with load engine: tapping sound
i suspect valves tapping, but aint an expert.

Did anyone had similar problem, and if it is valves knocking/tapping, how much/ how hard is to fix it.
Also tips on how can this be done are welcomed.

Cheers

[FROSTY:Me]

is it valves or is it the camchain?
Valve clearance3 adjustment is best carried out by a decent mechanic.
Cam chai replacement ditto.

[Katman]

If it was a valve clearance issue they would be tapping all the time regardless of whether the motor was under load or not.

Edit
(Sorry, just re-read it. Did you mean to say load or loud?)

[pete376403]

Valve clearances tend to close up over time (as the valve head / seat interface wears). Theres a tiny bit of wear between the cam and cam follower, but bugger all because it's bathed in oil almost all the time.
I'd expect valve noises in your motor to be a fairly quiet "tick" rather than a loud knock just because all the parts involved are so small and light.

Previous poster suggested cam chain and I'd go with that, too.

[6evil9]

thx guys
the noise is not VERY loud but noticable.
Does anyone know how much is to do valve adjustment and which good and cheap places in auckland?

thx alot

[6evil9]

is it valves or is it the camchain?
Valve clearance3 adjustment is best carried out by a decent mechanic.
Cam chai replacement ditto.

hey thx, is there a way to distinguish between valves tapping and camchain?

also why would camchain be loud?

cheers

[vifferman]

hey thx, is there a way to distinguish between valves tapping and camchain?

also why would camchain be loud?

Valve tappets tapping sounds sort of clicky, very regular, and speeds in time with the engine (but doesn't get louder).
Camchain noise is louder and more rattly, more irregular, and often gets quieter as the engine speeds up. It's usually caused by a worn camchain tensioner and/or chain and/or cam chain slipper and/or camchain guides, so the camchain is a bit loose. Just like your drive chain, if it's loose, it will tend to slap around a bit and make more noise, especially if it hits interior parts of the engine (which it can do if it's extremely borkt).

Here's a wee trick: you can use a long-bladed screwdriver as a makeshift stethoscope. Put the handle against your ear, and the tip against the rocker cover. This amplifies the noise (well, it doesn't really - just transmits it directly to your ear). Tappet noise is kinda distinctive, because of its regularity.

[FROSTY:Me]

If it was a valve clearance issue they would be tapping all the time regardless of whether the motor was under load or not.

Edit
(Sorry, just re-read it. Did you mean to say load or loud?)

Ahh but loud tappets cold are happy tappets -is that not true

[6evil9]

so does anyone know how much is to do valve clearence adjustment in the case it is the valves?

thx alot

[PirateJafa]

Looking at at least $400 to have the valve clearances done on a Bandit - 16 valves and they're a pain to get at.

'Tis why we love them.

[Bonez]

Hi everyone
bike: Suzuki GSF250 30,000ks

has a problem with load engine: tapping sound
i suspect valves tapping, but aint an expert.

Did anyone had similar problem, and if it is valves knocking/tapping, how much/ how hard is to fix it.
Also tips on how can this be done are welcomed.

Cheers

So you are saying the motor is making a "tapping" sound under load?
If so it could be "pinking". Try a higher octane fuel first.

Some engines get a bit of cam end float which is not much to woory about. Pays to get a qualified mechanic to have a listen if it's worrying you. Could be money well spent.

[6evil9]

nope, i did not say it was making tapping sound under load, just on an idle. not sure about the sound when riding though.

so is it really $400 to get it fixed?

does anyone have instructions how to do this?
cheers

[pete376403]

Is this a double overhead cam, four valve motor? Anyway, goes like this:
best done with a cold motor. You'll need a reasonable selection of hand tools.
remove the fuel tank (if it's above the motor. Remove the cam cover, which will probablly mean removing a bunch of hoses and wires. Take photos or make a drawing of where things go. When the cam cover is off, you need to rotate the motor until number one piston is at top dead centre. You also need to know what the correct valve clearances for both inlet and exhaust valves are. Take the appropriate feeler guage and slide it between the cam and cam follower. If the clearance is correct you should feel a slight drag on the guage. If the clearance is too big (or small) work through the feeler guages until you get the right "drag". Make a note of the measurement. When you have got the measurements for all the valves on that cylinder, rotate the crankshaft exactly one half turn, this should put pistons 2 & 3 (assuming 4 cylinder engine) at top dead centre (TDC) Assuming firing order of 1-3-4-2, you will now check the valves for cylinder 3. Repeat half turn of crank, measure for cylinder 4, then finally 2.
Compare your measurements to the specifications. For clearnaces that are too big you will have to replace the valve shim with a thicker one that will bring the clearace back to spec. for measurements that are under spec you wil have to replace the shim with a thinner one. Now for the exciting part.
Some engines (ie older GS Suzukis) have the shim between the cam and the cam follower (aka bucket) - with the appropriate tool you can depress the bucket and get the shim out without removing the cam. Other engines (eg FZR Yamaha) have the shim under the bucket, so you have to remove the cams.
When you have the shims out (being carefull to keep all the buckets in the corrrect order so they can be returned to their original locations) check the size - that is usually etched in the shim. If its not, you will have to measure the shim using a micrometer, so you can compare with the size required.
Visit your dealer and purchase the required shims.
Reassemble the shims / buckets / cams. check all the clearaces again to confirm they are correct. Also verify the cam timing is correct. When you are satisfied , replace the cam cover, plus any hoses and wires previously removed. replace the fuel tank, plus any other parts removed. test run the engine checking for leaks, nosies, etc.

Easy eh?!

Or you could just pay the dealer.