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timing advice wanted

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

timing advice wanted

Postby bluebob » Sun May 08, 2016 3:07 pm

just strobing the timing on new build engine.only covered about 10 mile.starts up easily. runs fine.looking for 17 degrees static timing.when strobed the arrow is on about 11 degrees at tick overand slightly higher.but by luck more than judgement it advances straight to 17 at high revs.obviously I am happy with that .my question is about the tickover on 11 degrees.is it common to have it so low .as I say it starts and pulls away no problem.and as the carb is still on the rich side I am happy the way it runs.the only thing I have noticed is it seems to want to tick over slightly higher than normal.i thought this may be a carburation thing but wanted to check timing first.now I am wondering if this is possibly becauase of timing being so retarded.any thoughts please
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Re: timing advice wanted

Postby Warkton Tornado No.1 » Sun May 08, 2016 4:58 pm

Although the only ignition that I have personal experience of, with a built in curve that advances in the very lower revs prior to retarding, is the internal rotor Motoplat for racing applications.

However, you don’t mention the make or type of ignition that you are using.

It is unlikely (if it is a variable type) that it should do anything other than retard.

If yours is advancing something like six degrees between tick-over & high revs, there is something seriously wrong, either in your measuring or the system. :?:
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Re: timing advice wanted

Postby bluebob » Sun May 08, 2016 5:52 pm

i am using a 12v bgm pro new stator.no added on gadgets.just looking for 17degrees static timing.i haven't used a strobe to check timing before so i didn't know what to expect.what i do know is that when the experts set timing for static systems they don't set it at low revs because the timing changes at higher revs.so if you are looking for say 17 as in my case you want it to be 17 at higher rev,so in that respect mine is ok,at least at the high end.so i knew to expect a change but didn't expect so much.si if i advance mine by 6 degrees to 17 at low revs i wll be dangerously high at high revs.i am confident my measurements are ok .the arrow advances 6 degrees and its just a fluke it settles on 17.
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Re: timing advice wanted

Postby MickYork » Sun May 08, 2016 6:01 pm

The timing should be 17 degree....regardless of high or low rev's !! the fact that it too far retarded and then moves indicates a problem. The 17 degree can sometimes "waver" around the mark but not by the amount you are saying. it also seems strange that you don't have a starting issue if it that far retarded. Could be a dodgy stator or flywheel but it does seem strange :?

saying all that if it's starting ok and looks to be running at 17 degrees then is it a problem ?

Might be worth doing a few plug chops to check it's running ok.
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Re: timing advice wanted

Postby bluebob » Sun May 08, 2016 6:23 pm

thanks mick.hopefully its ok.just wanted to check timing was ok before I started downjetting when its run in a bit,and then a few plug chops.was just surprised to see so much movement.any thoughts about my question about needing a high tickover .cheers
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Re: timing advice wanted

Postby MickYork » Sun May 08, 2016 6:40 pm

probably need someone more knowledgeable than me but it could be the excessive retard you've got. 11 degree might be causing it to struggle to tick over. There must be a point where the timing is too far retarded to tick over and you might be close to it with 11 degree.
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Re: timing advice wanted

Postby MK Monty » Sun May 08, 2016 8:17 pm

Static timing is what it says on the can. Static. I had similar results with a BGM stator spent ages messing with pickup height changing stators and in the end found the red bgm CDI was causing the problems. I had a black box retard unit and at first thought that was on the fritz so removed it from the system. Retimed it expecting it to be stable. It was all over the place. I would not be happy with it as it is you don't always ride full chat and you have no idea what it's doing poodling round town
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Re: timing advice wanted

Postby CHRIS in MARGATE » Sun May 08, 2016 8:37 pm

Anymore retarded and it'll run in reverse when you kick it over. I'm not joking !
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Re: timing advice wanted

Postby Warkton Tornado No.1 » Mon May 09, 2016 1:45 pm

Anymore retarded and it'll run in reverse when you kick it over. I'm not joking !


I've witnessed that happening...

thanks mick.hopefully its ok.just wanted to check timing was ok before I started downjetting when its run in a bit,and then a few plug chops.was just surprised to see so much movement.any thoughts about my question about needing a high tickover .cheers


BlueBob

I've just checked on BGM's website & the ignition is a fixed ignition. It doesn't retard itself & certainly shouldn't move @ all, let alone advance.

Something is drastically wrong.

Sorry to say that, but you may experience tiny 'flickers' in timing with a strobe but it should remain rock-steady @ whatever you've set it for.

BGM or MB should be the people you speak to about this, IMO.
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Re: timing advice wanted

Postby bluebob » Tue May 10, 2016 12:14 am

thanks Warkton.i agree that something is wrong.i have used the strobe again today with exactly the same result.took the flywheel off ,noticed that the pick up has been rubbing on the flywheel slightly.have been advised that this is wrong and there should be a slight gap between the two.i will have a word with the supplier tomorrow to see what they advise.maybe this is causing the fault.will let you know when I sort it .
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Re: timing advice wanted

Postby bluebob » Fri May 13, 2016 12:29 am

Quick update.took the new bgm stator off,replaced with the only stator I had ,which is an rough old indian stator,but I took it off a running engine so I knew it worked .fired her up,put strobe on,no problem.moved stator to where I wanted it and it sits at the 17 mark with only slight movement.seems the problem was slight contact between pick up and flywheel.thanks for your replies
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Re: timing advice wanted

Postby GP240 » Fri May 13, 2016 7:38 am

Glad you managed to sort it,

Is there a way of moving the pick-up on the other stator to stop it rubbing, bit of messing about but might save it from the bin.

If it does then clear you could refit and check if moving it did actually fix it.
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Re: timing advice wanted

Postby bluebob » Sat May 14, 2016 12:40 am

thanks gp240.going to have a look this weekend. sure something can be sorted with I bit of fettling.
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