LCGB Forums

The ability to post messages is restricted to LCGB members. Any questions contact us at lcgbadmin@googlemail.com

CDI, regulator, or stat pick up, or LT coil problem??

Technical help for Series one, two and three Lambrettas. Models include the Li, Li Special, TV, SX, GP, Serveta and API/SIL models

CDI, regulator, or stat pick up, or LT coil problem??

Postby lam1962brettagg » Fri Sep 17, 2021 5:17 pm

Hi All
appreciate any help to make me scoot better.
had engine rebuild last year with RT195, 30mm phbh, af exhaust, bgm stat. (LI 150 BATTERY MODEL AC/DC)
anyway, did 500miles or so and had problems took back to dealer who found the LT coil on the bgm was buggered so fitted a new bgm complete stat.......all fine for 250miles.
went out to start it today kick was a bit 'spongy' and started second kick, quickly spluttered, backfired and cut out.
checked and changed plug, seemed to be a poor spark, and did the same again.
hence the question in the subject title.
any suggestions welcome.
cheers
lam1962brettagg
 
Posts: 135
Joined: Mon Sep 11, 2017 5:37 pm
Location: far away

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby MickYork » Fri Sep 17, 2021 5:21 pm

possible sheared woodruff key....worth checking
MickYork
 
Posts: 1397
Joined: Sun Jun 01, 2014 8:37 am

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby lam1962brettagg » Fri Sep 17, 2021 10:40 pm

MickYork wrote:possible sheared woodruff key....worth checking

thanks Mick, will check that, never thought of that.
cheers
lam1962brettagg
 
Posts: 135
Joined: Mon Sep 11, 2017 5:37 pm
Location: far away

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby lam1962brettagg » Sat Sep 18, 2021 10:36 am

lam1962brettagg wrote:
MickYork wrote:possible sheared woodruff key....worth checking

thanks Mick, will check that, never thought of that.
cheers

took flywheel off this morning, hoping for an obvious fault.
and nothing??
the best at electrics I am is putting a battery in something.
stumped!! :cry:
lam1962brettagg
 
Posts: 135
Joined: Mon Sep 11, 2017 5:37 pm
Location: far away

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby Storkfoot » Sat Sep 18, 2021 11:54 am

What flywheel do you have and have you checked the timing with a strobe?

But, the reality is that it could be almost anything. I automatically associate backfires with electrical issues but too much air or two much fuel can cause a backfire.

Have you checked for air leaks at exhaust manifold or inlet manifold?

The spongy kickstart. Is it doing that intermittently or all the time? Prior to this issue, has the scooter been a good starter, say, in under 3 kicks?
User avatar
Storkfoot
 
Posts: 1559
Joined: Fri May 30, 2014 8:59 pm
Location: Merseyside

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby lam1962brettagg » Sat Sep 18, 2021 1:25 pm

not sure what type flywheel, bought new to fit gp crank, suspect its indian.
as for strobing, havent got one and not sure hiw to use anyway.
no airleaks from exhaust, when taking the flywheel off I did notice a very small amount of two stroke oil??
spongy kick is always first kick then always starts second kick.
checked stat plate hasnt moved.
lam1962brettagg
 
Posts: 135
Joined: Mon Sep 11, 2017 5:37 pm
Location: far away

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby MickYork » Sat Sep 18, 2021 1:54 pm

Next step would be a multimeter and check the readings on the stator.....Sticky's is helpful with what readings to expect.
MickYork
 
Posts: 1397
Joined: Sun Jun 01, 2014 8:37 am

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby Freight10 » Sun Sep 19, 2021 12:52 pm

Hi lam1962brettagg

Cant for 1 second say this is your issue, however myself and my mate have had the same issues recently, his was coming back from a rally, anyway we pulled out of the garage after refuelling and it back fired, cut out and locked up the rear wheel (still in gear of course) anyway after a lot of checking ect... his was found to be the fuel filter on the actual fuel tap inside the tank.. absolutely covered in crud, we only use premium fuel and full synthetic oil, so no reason for the crud to be there, unless of course its a bi product of the dreaded ethanol...

Ive just had exactly the same coming back from the IOW, last garage on A3 and refuelled, started albeit ticking over when throttle open and had to wait for it to clear, like it was bogged down with fuel, flooding..eventually i pulled away, back firing and eventually stopped before i even got out of the garage, so waited for recovery.

Havent taken mine apart yet, but im suspecting fuel rather than anything else at this stage...

Will definately be worth looking at the fuel tap though... my mate noticed that with his fast flow tap, when emptying the tank in to a can to inspect, the fuel was running extremely slow (obviously due to the crud build up)
User avatar
Freight10
 
Posts: 91
Joined: Sat May 31, 2014 11:32 am

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby Rich Oswald » Sun Sep 19, 2021 3:12 pm

Freight10 wrote:Hi lam1962brettagg

Cant for 1 second say this is your issue, however myself and my mate have had the same issues recently, his was coming back from a rally, anyway we pulled out of the garage after refuelling and it back fired, cut out and locked up the rear wheel (still in gear of course) anyway after a lot of checking ect... his was found to be the fuel filter on the actual fuel tap inside the tank.. absolutely covered in crud, we only use premium fuel and full synthetic oil, so no reason for the crud to be there, unless of course its a bi product of the dreaded ethanol...

Ive just had exactly the same coming back from the IOW, last garage on A3 and refuelled, started albeit ticking over when throttle open and had to wait for it to clear, like it was bogged down with fuel, flooding..eventually i pulled away, back firing and eventually stopped before i even got out of the garage, so waited for recovery.

Havent taken mine apart yet, but im suspecting fuel rather than anything else at this stage...

Will definately be worth looking at the fuel tap though... my mate noticed that with his fast flow tap, when emptying the tank in to a can to inspect, the fuel was running extremely slow (obviously due to the crud build up)


When you re-start your scooter after re-fuelling you are still using the old fuel from your float bowl for quite a few hundred yards down the road so if there's issues whilst still in the fuel station it's hardly likely to be due to the fuel just added. The actual act of re-fuelling may have stirred up some sediment or foreign bodies and blocked the filter either partially or totally and therefore no fuel was getting through to top the float bowl up. Premium fuel is less in demand so it's possible that the new fuel had stood in the pumps for a while and also possible that it was at the bottom of the storage tank where it is pumped from.
Your problem was most definitely flooding which can be avoided on some scooters by turning the fuel off well before turning the ignition off. If you have flooded it then a drain on your rubber bellows may be the remedy or if it is a foam filter, turn it horizontally, pointing backwards, that often helps.

Rich'
User avatar
Rich Oswald
 
Posts: 6843
Joined: Fri May 30, 2014 3:30 pm
Location: Wiseman From The East (East Of The Pennines That Is)

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby Freight10 » Sun Sep 19, 2021 3:32 pm

Not wanting to hijack this thread.....Thanks Rich, i will indeed investigate further.
User avatar
Freight10
 
Posts: 91
Joined: Sat May 31, 2014 11:32 am

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby lam1962brettagg » Mon Sep 20, 2021 8:32 am

Hi All
problem solved!
been out for a 30 mile blast and all ok apart from minor mixture screw adjustments.

previous to the above title problem I had a new bgm stat diagnosed as the problem some 200 miles previous. the lt coil packed up.
so...thought I would start there and investigate the lt coil first.
on inspection it was obvious the white wire had lost the insulation laquer and was arching on the stat body (brown patch on the stat plate visible)
coated with lots of fresh insulation laquer, everything back together, new plug and started first kick.
its even sorted the 'spongy first kick' problem.
so this is the second time I've had probs with a bgm lt coil!
I will be checking the tap at some point too as suggested above cheers
one to watch.
thanks for all the input.
:D
lam1962brettagg
 
Posts: 135
Joined: Mon Sep 11, 2017 5:37 pm
Location: far away

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby lam1962brettagg » Mon Sep 20, 2021 9:46 am

pic for those interested, you can see the brown patch caused by arching.
You do not have the required permissions to view the files attached to this post.
lam1962brettagg
 
Posts: 135
Joined: Mon Sep 11, 2017 5:37 pm
Location: far away

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby gp200ts1 » Mon Sep 20, 2021 1:16 pm

I've had problems with BGM stators with LT coils breaking down. had one where the lighting coils shorted somehow and all melted. also the slots need elongating to get 17 degrees BTDC.
Gave up with them and have only been using scootronic stators or indian ones that i have refurbished with Piaggio lt coils and pick up's.
gp200ts1
 
Posts: 170
Joined: Fri May 30, 2014 2:43 pm

Re: CDI, regulator, or stat pick up, or LT coil problem??

Postby coaster » Mon Sep 20, 2021 5:50 pm

lam1962brettagg wrote:pic for those interested, you can see the brown patch caused by arching.


Ah, that makes sense, its not the white wire, thasts the stator earth, the arcing is from the green which is from the LT coil.

I,ve maybe been lucky but my BGMs have been reliable but bthen I do like to 'harden' them by adding globs of araldite to all joits and lose wires. I did the same with my scootronic one although it did already have some on tbf.
User avatar
coaster
 
Posts: 2500
Joined: Fri May 30, 2014 1:00 pm
Location: Norfolk, Flying 8 Balls


Return to Series 1, 2 & 3

Who is online

Users browsing this forum: gaz_powell, Google [Bot] and 6 guests