Flywheel timing mark

[Josh1708]

Technical question.

Currently in the process of retiming my 172 due having a rough idle. mick at diamond Renault suggested my timing is out and he wasn’t wrong. My question is where should this mark on the flywheel sit I can see it has a 0degree mark and a 8degree mark with some lines in the bell housing casing(see picture) just curious as to where this line should sit. I do have the timing tools to do the job I will also note. Thanks

Sent from my iPhone using Tapatalk

 

[bloke]

0

 

[Josh1708]

Thanks bloke! What is the 8degree mark for[emoji848]?


Sent from my iPhone using Tapatalk

 

[MicKPM]

We’ve used this gearbox cast since the late 70’s, it’s an old strobe light marker.

You need to peg the crank on cyl1/4 at TDC (0 degrees) and then check the cam timing positions relative to that.

The cam timing notch is eccentric so the timing notches need to be on the lower half of the cams, not the upper... if they’re in the upper, you’re 180degrees out.

How they should sit if correct:



Sent from my iPhone using Tapatalk

 

[Josh1708]

Thanks MickPM you was was 100% right about the timing because when I put that flywheel mark on 0degree the cams are slightly out. That AST timing tool I used for the job has now gone in the bin and we ordered a new one at work lol. I’ll keep this thread updated!


Sent from my iPhone using Tapatalk

 

[Chrisgti6]

Are you using the crank locating pin?