Valve Clearance ?

[SadFool]

Timing is now 100%. Had to measure the clearance multiple times, as I got always slightly different values. But since the timing is now spot on, this is my result (looking at it as if standing behind the bike):
0.30 0.29
0.25 0.25

0.10 0.10
0.29 0.31

Based on the tolerance (Intake 0.13-0.19 and Exhaust 0.28-0.34) all intake clearances have to be done. What about the exhaust, should I adjust the 0.29? I guess the 0.30 and 0.31 should be alright.

But before I can tackle that, I had to stop working on the bike... 3 small hints, so no one will need to experience this:
1. Cover the spark plug hole. Otherwise a small screw might fall in.
2. If you use cable ties to ‘lock’ the cam chain to one of the cams, remove it before cranking the engine. Otherwise the cable tie will break and move with the chain all the way to the bottom of the engine, disappearing.completely.
3. Once you realise its not going well, stop working on the bike. Take a long break, go back to it the day after and find solutions for problem 1 & 2.

Still though, I do enjoy this project. As long as the weather stays sh1t...

Willl post an update tomorrow.


Cheers,
Marc

[Cadbury64]

Haha; I have personally experienced the "oh-sh1t" moment when you turn the crank and hear the cable tie snap. Lucky for me it hit the wall behind me, and did not dive into the crankcase. It is a good reason to use a brightly coloured cable tie!

[SadFool]

Haha; I have personally experienced the "oh-sh1t" moment when you turn the crank and hear the cable tie snap. Lucky for me it hit the wall behind me, and did not dive into the crankcase. It is a good reason to use a brightly coloured cable tie!

I had that idea... after my black cable tie snapped

[tony.mon]

Timing is now (looking at it as if standing behind the bike):
0.30 0.29
0.25 0.25

0.10 0.10
0.29 0.31

Based on the tolerance (Intake 0.13-0.19 and Exhaust 0.28-0.34) all intake clearances have to be done. What about the exhaust, should I adjust the 0.29? I guess the 0.30 and 0.31 should be alright.

Cheers,
Marc

If they're in tolerance, leave them alone.
The intake pair at 0.10 need new shims, slightly thinner than the ones you have at present.

The ones that concern me are the intake set at 0.25. That's 0.10 out of range. Assuming your measurements are correct. Suggest you recheck that set once again.

If your measurements are right, that's not normal wear, so it's likely that something has happened.
If it was seat wear the gap would be smaller, not bigger.

It's possible that a previous owner has fitted shims that are too small. (1)

It's also possible that you have a lot of carbon build-up on the valve seats. (2)

The other possibility is that the valves aren't seating squarely on the seats, and the main reason for this is when, after a previous standard cct failure, the valves have made acquaintance with the piston and are slightly bent. (3)

You could adjust the shims so that the clearance is once more within tolerance, but if it was me I would want to know which of the three reasons it was, and that means pulling the head off to have a look.

But before you do, check the shim sizes on that pair of inlets to see whether abnormally thin ones have been fitted.
From memory anything below 1.75 shim thickness isn't likely to be standard.

Lastly, before you order new shims, see if one of the old unwanted ones is the size you need on one of the others you want to adjust, as you can just swap one or two over and only buy the ones you haven't got.
You may not need to buy all of the ones you need and then end up with one or two left over which are the same size as the ones you just bought.

And don't panic, it's all easily fixed.

[SadFool]

I think I will - after getting that screw out of the spark plug hole from the rear cylinder - measure the whole lot again.

Yesterday I was putting the different values all towards the wrong timing, today I'm absolutely unsure whether this is the case. Once I have constant measurements after a couple of revolutions I will then have a look at the shims...

[AMCQ46]

after getting that screw out of the spark plug hole from the rear cylinder -

magnet bonded onto some stiff wire -- good luck

[tony.mon]

Or if non-magnetic aluminium or brass, blue tak on a stick - bit don't lose the blutak in there as well!

[SadFool]

No chance to get at it... can’t see it, tried magnetic tape (and i could hear it bouncing around), hoover, coat hanger, nothing.

Would there be a way to get at it through the exhaust

[E.Marquez]

No chance to get at it... can’t see it, tried magnetic tape (and i could hear it bouncing around), hoover, coat hanger, nothing.

Would there be a way to get at it through the exhaust

Assuming its a steel screw, a magnet on a piece of wire should do it. Wire like a coat hanger that you can pre bend so as to be able to sweep the bore to the cylinder wall
If you have compressed air and a good vacuum you might try air in a small metal tube with a hook at the end to move the screw around in the cylinder and then a vacuum though the largest tube you can still fit along side the air tube....the moving screw will likely pass by the end of the vacuum tube and you can pull it out from there.

And honestly, your already about 75% there for the work to pull the head...Id give what ever method you want to try about 30 min, take a coffee break, ring your preferred parts place and order a head gasket, go back to bike and remove head, get screw out of cylinder, spend an hour cleaning things up, cover in trash bags to keep clean, and toss in the town for a few days till head gasket arrives.

[MacV2]

No chance to get at it... can’t see it, tried magnetic tape (and i could hear it bouncing around), hoover, coat hanger, nothing.

Would there be a way to get at it through the exhaust

Assuming its a steel screw, a magnet on a piece of wire should do it. Wire like a coat hanger that you can pre bend so as to be able to sweep the bore to the cylinder wall
If you have compressed air and a good vacuum you might try air in a small metal tube with a hook at the end to move the screw around in the cylinder and then a vacuum though the largest tube you can still fit along side the air tube....the moving screw will likely pass by the end of the vacuum tube and you can pull it out from there.

And honestly, your already about 75% there for the work to pull the head...Id give what ever method you want to try about 30 min, take a coffee break, ring your preferred parts place and order a head gasket, go back to bike and remove head, get screw out of cylinder, spend an hour cleaning things up, cover in trash bags to keep clean, and toss in the town for a few days till head gasket arrives.

Hahaha...toss has a slightly different meaning over here Eric...He'd get arrested for that...

[E.Marquez]

No chance to get at it... can’t see it, tried magnetic tape (and i could hear it bouncing around), hoover, coat hanger, nothing.

Would there be a way to get at it through the exhaust

Assuming its a steel screw, a magnet on a piece of wire should do it. Wire like a coat hanger that you can pre bend so as to be able to sweep the bore to the cylinder wall
If you have compressed air and a good vacuum you might try air in a small metal tube with a hook at the end to move the screw around in the cylinder and then a vacuum though the largest tube you can still fit along side the air tube....the moving screw will likely pass by the end of the vacuum tube and you can pull it out from there.

And honestly, your already about 75% there for the work to pull the head...Id give what ever method you want to try about 30 min, take a coffee break, ring your preferred parts place and order a head gasket, go back to bike and remove head, get screw out of cylinder, spend an hour cleaning things up, cover in trash bags to keep clean, and toss in the town for a few days till head gasket arrives.

Hahaha...toss has a slightly different meaning over here Eric...He'd get arrested for that...

Dohhh,, err, ummm, give up for the night.....

[SadFool]

So, quick update here.

Screw is out from the rear cylinder, now waiting for the head gasket to arrive.

Front cylinder valve clearance once again measured, same result: 0.25 on both intakes. Took the shims out, FIL is 1.7, FIR is 1.8.

So this will basically mean, I will need 1.79 (1. on FIL, and 1.89 (1.90) on FIR, right?

I will be able to take one from the rear (1.9) for the front though - both intakes (which are too tight) on the rear are 1.9 and 1.95...


Cheers,
Marc

[SadFool]

So, shims changed and now am down to 0.15 on both intake valves.

Hopefully the head gasket for the rear arrives soon, so I can get her back together...

[sirch345]

Well done, you're getting there

Chris.

[VTRDark]

Screw is out from the rear cylinder, now waiting for the head gasket to arrive.

Front cylinder valve clearance once again measured

Hopefully you are aware that the measurments will change with the head on the bike and cam chain tensioned up. Doing valve clearance with the head off is only a rough guide and not accurate.