fault finding stator (all readings perfect) SORTED! :)

[olliewtf]

hmmm thats a good point. looks like it will have to come off again, and i will measure it up against the indian one. tbh though the laminates are solid now, i only tightened up the screws on the backplate and added washers underneath. It can only have made the most marginal difference to height, but it could well be enough to throw it off.
probably do that tomorrow, keep you eye out i do appreciate the help!

[Monty]

I wouldn't be to quick to give the cdi the thumbs up. I have had similar problems for a couple of months. 3 staters one I had used for years was replaced with a Brand new BGM only because I had snapped a couple of the lugs off. The BGM left me at the side of the road. To then start and run fine then just go blahh as if I had run out of fuel.
Change the plug or lead or just swear at it and it would run for weeks or a few days. In the end I swapped the brand new red BGM cdi with a Ducatti one off my special. Has run fine since but annoyingly so has the special. Coming home from the club the special went blaahh, No spark push the bugger home, replace the CDI with a new Ducati one and they are both fine.. To Be honest I was happy That the fault transferred as the special has always been bullet proof so pretty much proves it was the CDI. Could be weeks before I know for sure

[Adam_Winstone]

We may have already covered this but you are checking all of this with the loom's green disconnected from the CDI aren't you, just to make sure that you're not having a switch or loom failure?

I feel your frustration.

Adam

[olliewtf]

Cheers all.
Yes I have been trying without green from loom.
I have tried other cdi, but the reason I know it's nothing external apart from having retested is that the scoot broke down with the indian stator due to lt coil failing. It was still sparking and firing occasionally.
I hedged my bets and thought I'll repair the previous vespa conversion ststor as I'd tested both coils and it checked out. The only thing wrong was it was loose so I sorted that. Earths are definitely fine too.

In short, it's definitely a stator problem.

Lord knows what though!

I have to get to the bottom of it as I actually don't have any spare money for parts and I don't want it to beat me.
Keep the ideas coming, it's all helpful!!!
ThAnks again.

[mick1]

It might be worth investing in (or borrowing) a new stator. The worst scenario would be a spare stator (always handy) and at least you can confirm whether the existing stator is good or bad.

[olliewtf]

ive cracked it!
took stator off AGAIN and measured the pickup height compared to the indian one that came off. there was a very marginal difference, just under half a mm. I wasnt convinced that this was my problem, but wanted to do something different whilst i had the stator off again.

so, seeing as the only spare part available to me was the K2 pickup from the indian stator which i knew was working, i decided to swap them out as i had no other options left.

Just to clarify, the pickup on the vespa stator was reading perfectly, and i'd also gone around all the earth points again.
Logically speaking though, if the LT coil was reading fine and wasnt obviously damaged, the only thing stopping the damn thing from sparking was the trigger for the spark itself, ie the pickup.

Lo and behold, I now have a spark.

I am very grateful for everyone's input, I dont think anyone would guess that the pickup was knackered considering it was reading perfectly, so I think there's a lesson in there.

And i havent had to spend a penny, which is great because Im short on rent this month hahaha!

thanks again everyone!

[Adam_Winstone]

Well done for sorting it.

Noticing this on the initial post made me chuckle... "EDIT: its also definitely not an alignment issue as the flywheel and stator have worked together in the past."

Great to have it sorted though.

Adam

[Daggs]

I wouldn't be so sure the pick-up you've removed is "knackered" I thought alignment all along and still think it.

[olliewtf]

you could both be right.
from bottom of the backing plate, the recessed part not the part that sits inside the mag, to the top of the pickup magnet, was 36.6 mm on the vespa stator and 35.7mm on the indian. when i put the indian pickup on the vespa stator it came up at just under the indian stator.
thats not a lot to be fair, and a part of it could be due to poor measurement.
would be interest to hear if that would be enough to throw it off bearing in mind the vespa stator has worked with this flywheel, and yes the screws holding it together worked loose but were retightened.
either way its something to bear in mind in future but hey ho im back on the road!

[Adam_Winstone]

I've sorted a BGM stator alignment issue by adding 3 washers (1 under each securing bolt/lug) to 100% cure an alignment issue and those washers were surprisingly thin, to the point that you would have questioned alignment being the issue. That bike is still running reliably.

Adam