|
Post by gummybody on Dec 26, 2016 16:13:57 GMT
Hi Guys, a bit of help required please? I'm a newbee with a 1963 Vespa with a PX 125 engine. Have not had it long but was out last week and it died while doing about 40mph in 4th gear. Changed plug and off we went again with me feeling pleased. Failed again 4 times with symptoms = power loss before I managed to get home. Didn't really know a carb from a Stator but using this site and a few links, checked and there was no spark. Most of the Coil readings looked ok with a multi-meter except ( The guide I read said "Disconnect CDI block and check green on CDI block to earth = 600 - 1000 ohms, mine was 97K ohms but I did measure 500 ohms from green wire to earth so maybe I've misinterpreted and the measure is ok? ) Problem is I could only measure 35v AC on the green stator wire to earth when cranking and the guide said anything below 50v ac was a problem. Now looks like I need to purchase a Flywheel removal tool and have read about stripping threads and de-magnetizing the magnets, how careful do I need to be and any pointers before I mash up the timing? PS .. probably knew this kind of thing would be happening when I changed my mind and made a 63 Douglas my first scoot rather than the 125 Tourer on a 66 plate. Enjoying having a go at the moment though.
|
|
|
Post by mijapxman on Dec 29, 2016 14:40:15 GMT
Hi Gummybody Try this Set Meter to ohms, black probe to white wire, it's the earth, then red probe to The green wire, not the green to the ignition switch, the other green wire from the stator, it should read 450-540 ohms if it's outside that reading your ignition coil windings are damaged. A good kick with the sparkplug out should give you a peak voltage of 21-38 volts on your meter. Hope this helps if you don't have it fixed yet.☺
|
|
|
Post by ironsloth on Dec 29, 2016 17:07:14 GMT
Stick at it, once all the problems are sorted, you will be grinning like a Cheshire Cat again.
|
|
|
Post by gummybody on Dec 30, 2016 17:19:16 GMT
Hi mijapxman. Thanks, I'm reading 498 ohms between Green & White so that's spot on and 112 ohms on the Pickup with CDI disconnected so that's ok. I was working on the assumption that 35v ac when cranking was no good as I read somewhere else that I should see >50v ac I was looking toward the Stator being at fault. Based on your 21-38 v ac being ok, I will turn my attention to the CDI unit and replace it. Still waiting for the Flywheel tool anyway but thanks for the info. I'll keep you updated.
|
|
|
Post by henri on Dec 30, 2016 17:50:43 GMT
try a new plug 1st , then swap cdi's , ya stator readings are just in the ok range . you can meter cdi's but they can be still bad but metering ok . if the new plug n cdi dont cure it my nxt guess would be a pick-up failing under load . before totally die-ing like cdi's they can get hot n fail ,but after approx 20-mins cool down an scoot runs again , an repeat . H
|
|
|
Post by gummybody on Jan 3, 2017 22:18:37 GMT
Good news gents, went to Buzz Solomoto in Halifax today and got a new CDI unit. Fitted it tonight and bingo, I'm off and running again. mijapxman, thanks, it was your post about the peak voltage being ok that pointed me away from the Stator toward the CDI. Henri, same goes, you hit the nail on the head and ironsloth, you were right too, I am grinning like a Cheshire cat.
|
|
|
Post by mijapxman on Jan 4, 2017 18:31:15 GMT
I'm glad we could help, mate
|
|