Valve timing.. a bit stuck!

[Thainoodle]

Hi, I got into a bit of a pickle today while changing the belt on my gtx. Can anyone explain to me what timing marks I need to go off on the top and bottom pulleys please.

Never have any problem with bikes, and never get it right with cars!!

Thanks
Paul

[dozzum]

Theres a mark on the bottom pulley that needs to line up with a mark on the water pump pulley at the same time as you line up a mark on the top pulley with the front of the rocker box.

Got the one on my GT a peice of piss but for some reason the dx engine was a bastard when i did that a couple of months back.
Kept getting it all lined up with belt on then when we turned it over a full turn the slack would move round and it would be out 1 tooth.
Ended up setting it so it was one tooth out at the top, then once we turned it over it came right.

Hope that makes sense.

Good luck, enjoy.

Rich

[james butler]

the most important thing to look for is that when the crank is set up that the cam is set so that lobes on No 1 cylinder point up i.e both furthest away from the tappet. this is because this cylinder is on its ignition stroke therefore both valves need to be fully closed.

[Thainoodle]

Cheers guys, gonna give it another try in a bit!

Paul

[PeteGLi]

Check that the piston in No. 1 cylinder (nearest the cambelt) is at TDC (Top Dead Centre) when you align the pulley marks.

[Brunty]

Why would the water pump have a timing mark? LOL, intermediate sprocket perhaps....

Guide here

[Ian Carvell]

As Brunty says you dont have to just line up the bottom pulley and camshaft pulley you also have to time up the intermediate shaft because that drives the distrubutor.

If the intermediate shaft is timed up wrong the ignition timing will go out and it will be firing on the back wheel

You can check this by taking off the Dizzy cap....with the other two timing marks lined up the rotor arm should point directly at a notch on the rim of the distributor housing.

[Ian Carvell]

Oh and if the intermediate shaft is on the wrong place and you have assembled it all back together...you can just reset the igition timing rather than stripping it all again if you have a timing light. (provided it isn't so far out that the hall sensor connector hits the block!)

[dozzum]

my bad, head hung low.... i know what i meant.

[Thainoodle]

Cheers all sorted now!