HP4 and finding correct settings

[Lor@n]

Hello,

I hope my explanation will be clear...

I have an HP4 on my PX engine (177 pinasco, 60 stroke, sipe pipe...).

If I remember right I've read that some of the HP4 is not calibrated correctly, 4 degres of difference, right ?

On the engine casing I've put the stator plate at 21 degres by the suggestion of people on this forum (thanks by the way).

Then I've put back the HP4 to check it with a stroboscopic light, but the mark on the flywheel isn't near the mark on the flywheel cover (A and IT), let's say the mark on the flywheel cover are at 12 o'clock and the mark on the HP4 flywheel (when check with the strobo light) are at 9 or 10 o'clock.

So it's not at all a problem of 4 degres but a lot more...

What am I doing wrong ?

or the mark on the flywheel cover should not be trusted ?

So I put a PX flywheel instead of the HP4 and the timing mark with the strobo light is now near the mark on the flywheel cover but not at 21 degres like I did on the stator. The mark is on the Right of the marks A and IT.

Hope someone call gimme some help.

Thanks.

[karoo]

I wouldn't trust any marks I didn't put on myself! There are too many tolerances involved in timing so that a mark the factory will put at the same place on every engine cannot be accurate... It is okay for a standard engine but not for modified ones!

The 60mm crank isn't very accurate either... We once had a discussion about one that was 6 degrees off! Same for the HP4, every one is different! Some have retarded timing and some have advanced timing, even 10 degrees off is not unusual! Genuine Piaggio parts are closer in tolerances but they too aren't perfect...

[Lor@n]

So How can I be sure that my setting is right ?

What should I do ? What can I take as a reference ? because a strob light work wih the mark on the flywheel...

[SLR]

Put your own marks on the flywheel; take of Cylinder head and turn flywheel until the piston is in its upper turning point -> mark flywheel and casing!

get this one http://www.scooterforum.org/Downloads/gradscheibe.zip

and mark the 18° or whatever you want on the casing

now use the Strobo light to coorect our settings until the 0° mark on the flywheel is exactly above your 18° mark.

Done!

edit: sorry for my bad english!

Bearbeitet 21. Mai 2003 von SLR

[Lor@n]

Thanks a lot SLR, that's very clear !

I'll try it this week end.