HI evryone!

Just about to get back on the road after having a nice 6month ban and getting my GS500 K1 2001 out of the garage and doing a service at the same time.

SO far I have....
Changed the brake fluid
Changed main oil and filter
Check spark plugs
cleaned air filter
Check cylinder head bolts
Charged and topped up battery

And I will change the fork oil and oil stuff up as per normal.

However!

When I checked the valve clearances the exhaust vlaves were within the correct tolerance but the inlet valves are too tight to get any feeler guage in.  Is this important that I change it or can I get away with it being too tight?  The trouble is I do not know what size shims I have in there already and I cannot get a feeler guage reading so I cannot see how I can work out what size shims to put in, also I do not really want to faff around with changing shims!

Could tightening the cylinder head bolts have anything to do with this?  I do not know how it runs yet as the take etc, is off.

Anything else I should do before I get back on the road?
Hope you lot have had a better 6 months riding than me!

Cheers

john

Congrats on clearing your ban!  I looked and, sure enough, your last post was in June.  Welcome Back.

I've ridden MANY miles with intake valves that I think are too tight.  I can't tell for sure, because my thinnest feeler gauge blade is .04 mm.
 
And I know what you mean - how do you know whether you should drop a shim size, when the next size down might put you OVER the maximum recommended .08mm of clearance?  Grrrr.  I think the standard wisdom is "better too loose than too tight".

Anyway, two things.

1) Something that Srinath said a long time ago prompted me to measure the front edge of my feeler blades with some .001" dial calipers.  Wouldn't you know - there was a tiny "lip" on the edge from the manufacturing process!  The thickness of the middle of the blade was right on, but the part you USE was slightly too thick.  I used some VERY FINE sandpaper ("glasspaper" to you blokes?) to remove the burr, checking with my calipers after every few LIGHT strokes.

Who knows?  This might allow you to get your thinnest blade in there after all....

2) Whether the blade fits or not, you should be OK to start the bike up, get it "broken back in" with a long ride or two, and then check the clearances again.  This will also allow you to listen for valve sounds.

It is virtually impossible to get a 0.03 mm feeler to slide in, even if the gap is OK. They are so thin.

I depress the valve slightly with an allen key, insert the 0.03 mm feeler, and release the valve. You can then try to slide the feeler out - if it is stuck or has high resistance, then the gap is too small.

When I couldn't get a .002" or a .0015" feeler blade in the gap, I always checked for tightness of the bucket.  With the cam lobe turned away from the shim, see if the bucket can be turned freely with the tip of your finger.  If it can, there is some clearance and it is probably close to the .001" or .03 mm minimum spec.  I have let them go this way.

Remember, valve clearances increase considerably as the engine warms up since the coefficient of linear expansion is considerably greater for aluminum than for steel (the heighth of the head grows faster than the length of the valve).  When I've actually had a tight valve, the engine would idle much rougher when cold and then smooth out as it warmed up.  A good hint that you have a valve tighter than spec.

Great tips!

Maybe I will try to "fabricate" a .03 mm blade by sanding down the non-business end of my thinnest blade.  Then all I have to do is wait for Indian Summer to hit so I can stand to take the bike apart out in the shed.

Wait - it's November?  I may have to "bite the bullet" and find a space heater....

Cheers for your responses guys....

I was measuring the cams in the middle rather than the edges and it didn't seem to make any difference on mine... it still wouldn't go in!

The smallest size i tred at 0.0015" which I think is about 0.004mm so it could possibly still be the correct clearance as 0.003mm is the minium.

I did think it was wierd that the inlet valves are tighter than the outlet ones though?  Would tightening the cylinder head bolts have changed this?

The cams turn fine and they don't seem to be sticking or anything on the valves so I guess there is some clearance.  

I don't quite understand what you mean about the 'bucket' GSJack but I will find out!

I have left it for now anyway and but it back together as I think it is Ok and I don't want to play with it too much.  Hopefully I will be able to tell if they are too tight when I ride it again!

Cheers again!

John

Th "bucket" is the part that the shim sits in.  My Haynes manual calls it a "follower".



Question about step 5.11b: OK, they got the picture wrong.  But, does anyone else actually use pliers for this?  I guess the shim is hard enough that it wouldn't be damaged....

EDIT: Changed link from sisna.com to bbburma.net