VALVE TIMING WRONG. ?

[qwacker9]

hi, thanks for the diagram. its the same one as in my manual and thats the way i timed it up but still no compression.
is there any other way it can be timed up ?

[Steve Cooke]

As a rough guide the cam lobes should be pointing away from from each other, but as chrisu has said just check your clearances now and that will tell you if you,ve done the valves, it certainly sounds like you have.

[qwacker9]

thanks, i'll do that.
i think its between 0.05mm & 0.10mm normal clearance ye

[chrisu]

thats right

if you've done a valve it'll be MUCH bigger

[m1ks]

The valve timing can be out due to the crankshaft completing 2 full rotations to a single rotation of the camshafts.
your piston needs to be raised to TDC on both it's compression and exhaust stroke and accordingly your valves need to be doing different things.
The directions in the book show the camshaft position assuming that cyl 1 is at TDC on it's compression stroke, if it's at TDC on it's exhaust stroke it's out by 180 degree rotation of the cam.
Hence the reason for putting your finger over the plug hole, you'll feel the compression stroke as it comes around and you'll see the T mark pass twice, (this of course is with the head on BEFORE you dissasemble it)

Hope that makes a bit more sense?

Another thing to bear in mind is the possibility of slipping teeth when refitting everything.

[qwacker9]

hi, thats all a little confusing.
how do i tell the difference between TDC on it's compression stroke & TDC on it's exhaust stroke ?
i tried putting my finger over the no 4 plug hole and kicked it over but felt no pressure at all.

The valve timing can be out due to the crankshaft completing 2 full rotations to a single rotation of the camshafts.
your piston needs to be raised to TDC on both it's compression and exhaust stroke and accordingly your valves need to be doing different things.
The directions in the book show the camshaft position assuming that cyl 1 is at TDC on it's compression stroke, if it's at TDC on it's exhaust stroke it's out by 180 degree rotation of the cam.
Hence the reason for putting your finger over the plug hole, you'll feel the compression stroke as it comes around and you'll see the T mark pass twice, (this of course is with the head on BEFORE you dissasemble it)

Hope that makes a bit more sense?

Another thing to bear in mind is the possibility of slipping teeth when refitting everything.

[m1ks]

At this stage it's sort of shutting the stable door after the horse has bolted.
The checks as mentioned should be carried out before dissasembly.

All you can really do at this point is take the rocker off, check clearances and re-check timing marks and re-align if required, then do a compression check, if you get nothing at all, head off to check the valves, as mentioned before it takes surprisingly little to bend a valve hence the rotating by hand.

[kev edwards]

If the set up is as it is in the workshop manual diagram , the motor will be set on piston 1 firing stroke , if you look into the spark plug hole of number one left side of bike you will not see any valves , where as on number 4 if you look into spark plug hole you should see the exhaust valve , if you have this and still no compression check clearances on valves if they are way over the top its head off and new valves .

[dreadmanbastard]

hi, may i quote kev edwards from a previous thread...

"when the crank is on the T mark, the cut out on the right hand end of exhaust cam should be pointing towards the front of bike paralel with the head, and the cut out on the right hand end of inlet cam should be pointing towards the rear of the bike paralel with the head. "

not nessesarly relavant but i found that useful to know when dealing with timing issues.