Valve clearances

[Graeme]

1990 gsxr750.

It sounded like one valve had too much clearance, but when I checked, they were all tight (about 0.05 to 0.08)

I set them to 0.10 on the inlet and 0.18 on the exhaust as it's the lowest the boom suggests.

I don't know of the original tap has gone now, or if it's just drowned out by the fact I can now hear all the tappets!

It's how it apparently should be now, but I don't like it. Can I close them up a bit? What does everyone else run on oil cooled motors?

[clivegto]

Fit a turbo or a race exhaust that way you won't hear them rattling away except in the back of your mind 

[Graeme]

11 minutes ago, clivegto said:

Fit a turbo or a race exhaust that way you won't hear them rattling away except in the back of your mind 

I would quite like to do a 750 turbo, but I know that's a bit silly.

It is high miles and burns a bit of oil, it's not worth doing anything to this motor. I'll run it for the summer though. I'd just quite like to quieten it down a bit in the mean time.

Edited June 12 by Graeme

[Dezza]

Wearing ear plugs whilst riding will solve the 'problem.' And they're good for preventing hearing damage due to constant wind noise so win-win .

[DAZ]

They don't call them tappets for nothing , a tappy tappet is a happy tappet and all that .... Seriously though std clearances are fine  they are a bit noisier than modern watercooled stuff not because of the clearances but because of the coolant jacket muffling the noise of combustion I think , is the cam lobe ok on the one that wasn't tight ? 

[dupersunc]

Not a blowing exhaust header flange is it?

[Graeme]

19 minutes ago, DAZ said:

They don't call them tappets for nothing , a tappy tappet is a happy tappet and all that .... Seriously though std clearances are fine  they are a bit noisier than modern watercooled stuff not because of the clearances but because of the coolant jacket muffling the noise of combustion I think , is the cam lobe ok on the one that wasn't tight ? 

They were all tight. The noise, whatever it was, wasn't a loose tappet

[Graeme]

16 minutes ago, dupersunc said:

Not a blowing exhaust header flange is it?

Don't think so, but it's on my list of things to check

[Graeme]

20 minutes ago, DAZ said:

They don't call them tappets for nothing , a tappy tappet is a happy tappet and all that .... Seriously though std clearances are fine  they are a bit noisier than modern watercooled stuff not because of the clearances but because of the coolant jacket muffling the noise of combustion I think , is the cam lobe ok on the one that wasn't tight ? 

Yeah, but in 30 years of playing with cars, bikes and engines from the 1940s to the 1990s, I don't think I've ever had to accept tappet noise. Normally, set them right, and things are quiet. 

 

[Graeme]

I've read on others oil cooled motors people run inlet and exhaust the same. Might try closing the exhausts up a little. It ran fine, and quiet, before. But although everything had clearance, they were maybe a little tight for comfort.

[Upshotknothole]

Welcome to oil cooled GSXR engines, they're all noisy, including the later shim heads. I've always thought they sounded like sewing machines when cruising on the freeway. Even the one time I lost a piston due to loose tappets, the top end was barely louder than normal when I noticed the cloud of smoke behind me. 

[Graeme]

My 88 was quiet.

If it's just how they are, and the only way to get them quiet is to run the clearances riskily tight, then I'll learn to ignore it.

[Graeme]

Checked my other manual and it's different, this one says 0.10 to 0.15 on intake and exhaust, not 0.18 to 0.23 on exhaust.

I'll close them up a bit.

[Upshotknothole]

This is straight from the Suzuki factory manual.

For 1990 750L

IN 0.10 - 0.15

EX 0.18 - 0.23

88 750Js had the intake and exhaust the same at 0.10 - 0.15

89 750Ks are the same as 90. 

IN 0.10 - 0.15

EX 0.18 - 0.23

Any noticeable wear on the cam lobes or the rocker arms? 

[Graeme]

Just now, Upshotknothole said:

This is straight from the Suzuki factory manual.

For 1990 750L

IN 0.10 - 0.15

EX 0.18 - 0.23

88 750Js had the intake and exhaust the same at 0.10 - 0.15

89 750Ks are the same as 90. 

IN 0.10 - 0.15

EX 0.18 - 0.23

Any noticeable wear on the cam lobes or the rocker arms? 

No. Previous owner said he had replaced the cams. They look good and rockers feel good on their shafts.

 

Your factory manual figures tally with Haynes. The clymer manual says intake and exhaust the same.

[DAZ]

53 minutes ago, Graeme said:

Yeah, but in 30 years of playing with cars, bikes and engines from the 1940s to the 1990s, I don't think I've ever had to accept tappet noise. Normally, set them right, and things are quiet. 

 

The thing I find is that the clearances if they move tend to close up , hence the happy tappet thing ,not saying it should sound like the proverbial bag of spanners, but if it's too tight and quiet..

[Graeme]

15 minutes ago, DAZ said:

The thing I find is that the clearances if they move tend to close up , hence the happy tappet thing ,not saying it should sound like the proverbial bag of spanners, but if it's too tight and quiet..

Yep, 100%. 

[Buzuki]

16 hours ago, Graeme said:

... and rockers feel good on their shafts...

 

 

You have to check rockers hard-chromed surface on the first place , since rockers almost never wear on their shafts , every even smallest pitting on cam lobes or on the hard-chromed rockers surfaces results in increased level of noise .