Modern Vespa

Hello all,

Just a bit confused with my new set up....

I have a Rally which Ive put a new mazz crank/ PX stator and flywheel on.

Ive found TDC and found 23deg (pointed my snips at top of pic 2)

The puzzling thing is that the pick up seem someway anticlockwise from this point. Most pictures I see, seem to have the pick up down in this area.

Now Ive had it started once (before the flywheel popped off-another story!) so it would seem in the right ballpark, but wasnt started long enough for me to time it up.

Am I missing something here or do I file the slots to do this initial set up and get it closer to pointing to the BTDC mark? It doesnt seem to want to start at the mo' and Im wondering why a perfectly good stator would need filing?
cheers Kevin

Kevin:

I do not know the answer to your question, but I will be watching as I am currently doing the same thing with my Rally 200 with a Vespatronic Stator.

so if you are inclined, update your progress as you find out what is going on.

it will help my struggles.

thank you.

Hi Craig, will do:-)

To get you going, Ive scanned a page from Beedspeed site that should get you in the right ballpark...

There is no point in having a conversation about this until you see where your firing point is with a strobe. Yes, I'll say that it looks like the position of the pick-up is a bit advanced. But you should still be able to get an idea of how far you'll need to move it by strobing it.

OK SFvsr thanks but...I'll play dimbo here...its not too hard!...

How do I strobe it if it wont start. Vicious circle surely?

Kevin

If I'm understanding your post right, you are going about this wrong.
With the flywheel on find tdc and mark both the flywheel and the case with a marking that lines up at tdc.

Now make a marking on the flywheel to indicate the point that is 24 degrees prior to tdc as the flywheel spins past the case marking.

Personally I make marks with a center punch and wipe white paint into them. I also make my marks at 15/20/25 degrees and "eyeball" my target when strobing it.

Now you need to strobe it and adjust accordingly. Start fully retarded and turn the stator anti clockwise as needed to get desired advance.

What is the standard firing point for the Rally 200 -

22, 23, or 24 degrees before TDC ?

mine is a 1974.

Yes I realize this is just a starting point to proper placement.

Craig

btw.

what exactly is the flywheel triggering contacts?

in beedspeed printout

Beedspeed says 24 b TDC

Craig,
I believe 23degs is fine for a standard Rally...

I wasn't too happy with that explanation, so try this one. I think its a bit better. Not sure if its different for a variable timing unit. Wouldnt think so.

I appreciate the timing help but my original questions getting lost. Do I really need to be filing extended slots in a PX Stator to fit into a Rally conversion? I dont mind doing it but would like to know if others have had to do this as well.

Kevin

I also had to enlarge the slots on the stator for my 74 rally ducati conversion.

thanks BH...thats what I was after.

The engine has actually started with the original slots so I see no reason why it wont again (when the rest of the units are clagged back on) so I'll hold back on any file work until I find that 23dbtc is not attainable.

Cheers Kevin

I've had to do this on every conversion I've carried out.

righty oh chaps..thanks. I take it not by an awful amount? Half as long again? Plenty to do in the meantime:-)

is that stator pickup rubbing...??
looks like it is

use some marker on the inside of the flywheel and check it after letting her idle for 5 mins... if the marker is rubbed off then there is a clearance issue.

Either the stator can be adjusted or the crank is not true and has a wobble. New cranks are not alway true.

Hi Spider,
It was rubbing, youre right, but I dressed it slightly and now were fine. The same was happening with the top coil hence the red felt tip..
Not sure how you adjust the pick up though? agin, the same with the coils because theirs no adjustment on the px's unlike earlier models?

Cheers Kevin

is not the law but...

since every case has very slight differences in there machining or whatever I have found that some aftermarket non OG stator back plates are not "tight."

I had one vespatronic stator plate that could be "adjusted" a little... about a 1/10mm which help me prevent rubbing.

&

it looks as if you are not using any wavy washer (or flat and a lock) under the stator bolts... if so do use some blue locktight on those bolts. It sucks when those fall out and ruin the stator coils. Seen that.

years ago I had to grind those 3 bolts for better clearance on my smallframe...

thanks all for your advice....

Ive got the bike up and running by extending the slots anticlockwise about 8or 9mm. For one reason or another(idiocy) I now realise Im nowhere near 23degrees. It starts (eventually) and ticks over but at about 12deg.

To get me to 24 I'll need to drill stator holes rather than extend these slots further. In other words I need to rotate that staot plate clockwise about another 10mm. Have I missed a trick or has anyone needed to do this by that amount?
I dont have an issue doing it, it just seems a way off from the factory bossed slots.

Kevin

This doesn't sound right. You should only need to grind out the existing slots on the stator. Are you sure you're timing it right? You can't put the timing marks on the engine case, you put them on the flywheel. Pick 1 single place on the case that will be your point of reference that you can easily see when it is being strobbed with a timing light.

SIP has a great how-to video on timing (although it's in German with English subtitles.)

Also worth mentioning is that i had to grind off some excess material from the back of the stator so that it sits flat on the cases.
I originally gave a so-called professional to a rebuild an engine with '74 Rally cases, 12v efl conversion.
He did not notice the stator did not sit flush and proceeded to torque down the 3 x screws and cracked the stator. (F@EURkwit)! He didn't even notice! So check the stator plate does not 'rock' before you screw it in properly.
This is why i joined this site, to learn how to do things properly, and if you're lucky, sometimes even better!!

some after market stators like the vespatronic, parmakit and varitronic stators are built in 2 pieces...

you can unbolt these from the back plate and rotate the coils

that might work

Its Official. I'm the village idiot

I was retarding(clockwise) and not advancing.
Now starts up and idles fine.

I had set the stator in the middle of the slots initially and it never worked.
Rotated clockwise and it started up...
Unscrewed......ahh what the hell, I goofed up! Luckily no damage done apart from some particularly natty elongated slots

Lets all move on. Nothing to see here.

Thanks for the advice chaps. Id like to think another newbie may read this one day and learn from this dufus

cheers Kevin