TDC

[DougieDoug]

does any1 know when lining up for TDC which way round the bottom pully thing has got to be as it has 2 marks on it? or does it matter? cheers doug

[DougieDoug]

pully thing = timing rotor i think

[tk400]

shine a torch down the plug hole and see if its at TDC. then line up the two TDC marks with the case split axis...

[zxrjohn14]

numbers at the top (1185..........i think) and as tk400 says, in line with the split of the engine cases.

[DougieDoug]

ok cheers, also me and a mate tried doing this, put the engine back in n tried starting it on the button but it just sort of bopped a few times n backfired, we tried bumping it n when the clutch was let out the engine made a clicking noise (not the normal clutch rattle) which it didnt do b4. it still didnt start.
if the timing rotar is at tdc and then does a full turn will it still be tdc?
just to make sure,
1 and 4 should be up the top?
the marks on the cams should be facing outwards?
sorry to be a pain and cheers for ur help. doug

[parby81]

could be 180 degrees out mate

[DougieDoug]

im sat infront of it now, the two Ts are lined up with the splits in the casings and the numbers at the top, pistons 1 and 4 are at the top, and the marks on the cams are in the correct place. if i turn the bottom pully 360 degrees the marks on the cams are opposite where they are meant to be! could the cams both be 180 degrees out?

[DougieDoug]

could be 180 degrees out mate

sorry didnt see this

[tk400]

its a four stroke....the cams do one rev to every two revs of the crank. So what you are seeing is fine. as long as at one point the marks all line up and pistons 1,4 are at TDC. also be careful that you actually are not out a tooth on either cam. It is important to check all the marks once the tensioner is installed and all slack is out of the system. do the first rotation carefully incase you are out a tooth you may have valves meeting pistons.....with the cams and deck height I have I know one tooth equals disaster...lol..cheers

[DougieDoug]

everything is lined up perfect except the inlet cam which is a little bit out but if i move it round 1 tooth its even further out the other way! is this normal? in the manual it says that the mark on the inlet cam should be 30 teeth away from the mark on the outlet cam, which it is. ive turned it over by hand and nothing seems to be hitting anything,

[parby81]

if the chain isn't new then it will have some stretch in it, this will account for them not being quite bang on with the 30 teeth

[DougieDoug]

should it still work? or should i think about replacing it?

[masterofinsanity]

you might want to look at the post Mori Man has put in the "know your stuff" on stripping/rebuilding the engine.