Severe Rattle from Top of Cylinder Head

[Guest]

It was time to do an oil change and check the valve clearances on my 550 motor with 650 top end.

Most of the clearances were OK, just had to swap a couple and fit a new one. As usual I turned the motor over a few times after putting the new shims in place and rechecked clearances again.

I buttoned it up, valve cover on, tank, seat, etc

It was a couple of weeks before I actually started it up again. Which I did yesterday. On start-up there was a sever rattle coming from the top of the head. I was very surprised, never expected that to happed as the motor has usually run very quietly. I was about to shut it down when the noise reduced a bit so I let it run a bit longer and after about 30 secs the noise had disappeared, although the motor did not seem quiet as smooth as before the valve adjustment.

I could understand the rattle if I had an incorrect size shim in the motor, or if something had dislodged and enabled the shim to seat a bit lower in the bucket, but I can't understand how or why the noise would go away like that.

It's like it took that long for oil to reach the top end before the noise went away, but lack of oil to me would have a different sound to that, more scraping or grinding.

I did not from memory oil the cam lobes before replacing the valve cover, but there was oil around up there as I had done 6,000 miles prior to this exercise.

I put the bike back in the shed and removed the valve cover but could not measure the clearances as the motor had run for about five minutes and the head was reasonably warm. So when I get home from work today I will check all the clearances again to see if one tappet has loosened up.

Could it be a bucket jammed in it's bore momentarily?

Any suggestions as to what happened? I am meticulous with valve adjustments and can't believe I made an error when doing them, but anything is possible.

Anyone want to have a guess?

P.S. My intention was to warm the engine up to be able to do an oil change, but I did not get that far.

[Nessism]

Hey Don,

Wonder if one of the shims tried to jump out of the bucket. Might be your sticking bucket thing too.

Not sure what to suggest other than monitor carefully.

[BadBillyB]

Hey there Don....Did you have the spark plugs out of the head ????.....Billy

[Suzuki_Don]

Billy I did have the spark plugs out when doing the clearances to make it easier to turn over. But I put them back in before I started it. joke

[BadBillyB]

I am wondering if something got into the combustion chamber, was hammered, and sent out the exhaust.....Billy

[Suzuki_Don]

OK thanks Billy

[hampshirehog]

Didn't accidentally drop a Kawasaki shim in there by mistake? It might have rattled around before the oil make it stick down.

[Suzuki_Don]

Didn't accidentally drop a Kawasaki shim in there by mistake? It might have rattled around before the oil make it stick down.

No Wally, I don't have any other shims except Suzuki ones. I am missing a two bob piece though, wonder if that got in there by mistake.

Thanks for the thought though. At this stage it could be anything.

I'm even starting to wonder if one of the spark plugs protruded a bit too far into the combustion space as I used the originals and they would have already had crushed washers. If you get my drift.

Just finished my tea and am going outside now to measure the clearances. I will report back.

[Suzuki_Don]

I just checked the clearances again. But before doing that I checked that the cam holder bolts were tight. All were OK except for one that was quite loose. I tightened it a good turn at least. BTW are these bolts supposed to have Loctite on them to prevent them from loosening. I torqued all these bolts down when I rebuilt the engine. That was 6000 miles ago.

I checked the clearances and all seemed OK except one. It was .13mm, I was then called away for a while and when I came back and rechecked them all again I found that they were all in spec. All I can think is that I had the camshaft in the wrong position when I got the .13mm reading. Maybe I forgot to turn it over after doing the previous checks, remembering that there are four different positions for the cams to be in to doing the relevant checking.

These are my clearances as they stand now.

#1 EX - .07
#2 EX - .08
#3 EX - .09
#4 EX - .08

#1 IN - .08
#2 IN - .08
#3 IN - .07
#4 IN - .09

I will remeasure them again tomorrow night as I had a lot of disturbances tonight and kept getting called away to do family duties (taxi service), etc.

So I will check them one more time before buttoning it up again.

[mike_of_bbg]

Yes, Blue Loctite is recommended on the cam holder bolts.

[Suzuki_Don]

Yes, Blue Loctite is recommended on the cam holder bolts.

Thanks Mike, I had better do them in turn then before I put it all back to bed.

[TeamDar]

Yes, Blue Loctite is recommended on the cam holder bolts.

I have never used loctite on those bolts nor have I ever seen that recommended in any service manual.

[mike_of_bbg]

I think it was recommended in my Clymer service manual. Obviously if he had one back out, it's not going to hurt...

[tkent02]

I am missing a two bob piece though, wonder if that got in there by mistake.

What's a two bob piece?

[hampshirehog]

What's a two bob piece?

The correct term would be a florin. Also known as a two shilling bit. It's old money (pre-decimalisation) - the equivalent of 10 pence (or 10 new pennies if you're still hankering after a time that probably didn't exist when things were so much better than they are today).

A British silver coin almost exactly the same size as a shim and ideal for sticking in there when doing a shim shuffle.