Dying Engine

[Tony Hart]

Any pointer as to what might be causing one of my engines to randomly die? It doesn’t splutter as if running out of fuel and can happen after six or twenty six miles. When it does happen the revs just carry on dropping to 0 as I come off the throttle.

(Casa 185 with 25mm rubber mounted carb (drilled airbox). 12V static ignition and Casa S2 clubman style exhaust)

Cheers for any advice

Tony

[HxPaul]

It doesn't sound like carb as you've had 3 different carbs on it,a 20mm dellorto,a 22mm scootopia copy and a 25mm PHBL dellorto.So it may be electrical,try swapping your cdi first,if that doesn't do the trick it sounds like either your pick-up or your LT coil on the stator plate.
EDIT
Check your plug,plug cap and HT lead.Also check the breather in the fuel cap.

[MickYork]

Where's it say 3 carbs ?

What's the plug like when it dies? brown, oily, etc

Petrol tank breather a good call.

I'd check the flow rate from tank as well.

Try running without the air filter (check plug to make sure your not too lean).

[HxPaul]

viewtopic.php?f=6&t=7900

[Tony Hart]

Cheers. (Well done Paul for tracking this one!) A year and 2000 miles and it is still giving me grief Will go down the electrical route. (Already checked breather and flow rate!) The small mercies are that it starts again first kick and I have another scooter to get to work on

Will post if I get any joy

[HxPaul]

If you have to change the stator plate,try another flywheel while your in there.I once had an Indian 12v flywheel that gave me a lot of trouble,I changed it and the troubles went away.

[MK Monty]

If its just going Blaaaah at any speed Go for electrical. disconnect your green from the ignition switch just to be sure, make sure your spark plug cap is not being pushed up and off when you sit on and go over bumps, then look at CDI and then stator, plug colour and carb settings are a different mater IMO. The Casa kit I had was the most reliable kit I ever had and I'm sure the B**** who pinched the bike thinks the same.
I had the same fault, Blaaah would kick of strait away and be fine or only travel 30 yds, I went down the stator route, New BGM kit swapped the CDI first, then had floating timing and investigated pickup heights put a shim under the pickup to raise it and thought I had got it, ( he sells them with shims now) swapped the new BGM CDI for one off my other bike and it was sorted, daft thing was the other bike ran with the red BGM CDI for weeks then it to went Blaaah, replaced the CD and that was then good. Electrickery.....I would be tempted to go down the external pickup or stator CDI combinations that do away with the LT coil if I got more of the same

[Tony Hart]

Well it wasn’t the CDI so in the end I fitted a different, brand new CDI (scootopia), a new stator (BGM) and a flywheel I had in the garage. Thirty mile plus commute to work and all seems good.

For some reason my timing gun didn’t work with the red Scootopia CDI so I ended up piggy backing a second CDI on to check timing.