LiS 150 stator slots not long enough (points)

[johnny650]

thanks for the clarification and help Adam ...much appreciated.
i already have a broken Stator tab on one of my stators so i am wary of ruining another expensive stator hence my reluctance to go that route.

It looks like this is an issue with the points rather than any other component so i'[ll order up another set of points and try that first as it could be an easy fix.
thanks for your help matey

[johnny650]

UPDATE
Today I took another spare series 3 Dansi Stator and completely rewired it , new points and condenser .

I double checked that I had marked TDC correctly on the new Mag Housing and it was correct.

With the replacement Stator fitted it has exactly the same issue as before. The points are opening way too early even with the stator retarded at its fullest extreme clockwise on the slots .

Thats a second OEM stator and points with the same result so I think I can safely eliminate them now,

The points are opening at 46 degrees before TDC !......

WTF ?

The crankcase is an Italian 64 Li150S to which I've fitted an Indian 200cc small block engine and replacement Indian Mag Housing . The crank is a standard OEM Li SX series 3 crank with a standard conrod.

Mmmmm ...... I'm beginning to think I can see a possible source of the problem and it begins with P for Piston
If the piston height is not the same as the standard 150cc then that could alter the TDC position I guess.

Can anyone think of anything that could cause the timing to be 46 degrees advanced with the stator fully retarded on the slots ?

[Adam_Winstone]

Please can I confirm that you've checked the accuracy of any TDC and firing point marks, rather than trusting anything that might already be on the engine?

[Adam_Winstone]

If you change the mag, flywheel or the crank then previous marks are worth nothing and you'll need to make new.

Changing the piston makes no difference to TDC as it represents the highest point of piston travel (any piston) as controlled by the crankshaft. TDC relates to the crank being at maximum throw and this will not differ as a result of a piston change. Sure, the height of the piston might make a positive stop mark change slightly but it would change the stop marks equally in both directions, clockwise and anti-clockwise, the TDC being the mid point between the 2 marks... and with TDC being the same. Likewise, a change of piston would not change the TDC point if you were using a dial gauge.

[johnny650]

yes I said in my last post that I checked and double checked that I have the correct TDC .......besides its a brand new mag housing
.
Even if I stuck a pin in the mag housing blindfold and guessed TDC I could hardly be 46 crank degrees out

I checked the keyway on the 6 pole Ducatti brass Flywheel (early series 3) and its correctly positioned and the boss has never been removed and the aluminium fins have not moved .

I can't think of anything else that would effect the TDC that much . ?

[johnny650]

the only thing that I can think of is that the mag housing (Indian) has had the stator fixing stud holes drilled and tapped in the wrong positions . I have another engine so I'll strip the flywheel and stator out of that tomorrow and see if there is any difference in the relative positions of TDC and the stator

[firekdp]

You should be able to see if the stator is that far out, by the loom not lining up with the exit hole.
How does yours compare with mine at 19°?
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[johnny650]

thanks firekdp . I probably haven't made myself very clear sorry....its difficult with just a few typed words and no pictures .

I have fitted the stator plates and with the stator at full clockwise position the points are opening 46 degrees before TDC
The difference between fully advanced and fully retarded on the stator slots is around 10-12 degrees maximum adjustment so you can see my consternation ......what on earth could cause the points to open so early ?

The crank is standard Li SX
the flywheel is a standard Ducati 6 pole brass with ali fins
the stators are both bog standard series 3 Dansi
I have fitted 2x different points
the flywheel keyway is in the correct position according to Sticky as is the crank keyway obviously.

That just leaves the one unknown component ............a Indian series 3 Mag Housing.
If the stator fixing studs are in the wrong position that could cause the timing discrepancy but I've no way of knowing because I do not have a OEM Italian S£ Mag housing to compare it with.

[HxPaul]

It cant be that the mag housing stator fixing studs/bolts are in the wrong position,as the studs/bolts go through the mag housing into the engine case.

[johnny650]

sorry for the delay firekdp ..had lots of 'honey do jobs'

thank you for posting the picture... I see what you are trying to do.
Its difficult to compare the 2x because my engine is on a bench and yours is at a different angle and I cannot see the outer part of your mag housing. What do you think ? are the stator studs in the same relative positions ?