Scooterotica

Please don't take this the wrong way but, if you are messing with tuned Lambretta engines, you really need to buy a strobe and figure out how to use it. They are very straightforward

storkfoot wrote:Please don't take this the wrong way but, if you are messing with tuned Lambretta engines, you really need to buy a strobe and figure out how to use it. They are very straightforward

Not taken in the wrong way at all mate - I'm a good student - here to learn. To be honest it's one of the only areas i haven't tried to do myself yet

alanscottj wrote:

storkfoot wrote:Please don't take this the wrong way but, if you are messing with tuned Lambretta engines, you really need to buy a strobe and figure out how to use it. They are very straightforward

Not taken in the wrong way at all mate - I'm a good student - here to learn. To be honest it's one of the only areas i haven't tried to do myself yet

Got myself a strobe gun this afternoon so will have a play later and see where the timing is at

Well done

Remember the strobe is only as accurate as your TDC mark..........and the other marks based on that.

mick1 wrote:Well done

Remember the strobe is only as accurate as your TDC mark..........and the other marks based on that.

Yeah, got a stopper that screws into the spark plug and a Cam Lam timing disc

That's exactly what I have. I have not strobed a Varitronic. I presume they strobe the same?

Okay - here's one for ya!

Set up the strobe light - started the engine - started to strobe - could clearly see the arrow pointing upwards at dead on 12 o'clock - gave a little throttle - arrow retarded a few degrees, all good I thought, so gave a little bit more throttle and the arrow retarded a touch more (only 7 or 8 degrees) then bam it was gone! Stopped engine - started again perfect - same again, retarded 7 or 8 degrees then it disappeared again, this time I left engine running and found the arrow again - virtually opposite at 6 o'clock!!! So, after about 6000 revs my Varitronic is retarding about 180 degrees!

I'm no expert but I would say that is what is wrong with my engine

What i don't know though is what is causing it???

Any help most appreciated - as always!

Scott

Could be the double spark on the Varitronic causing the strobe to have hic-ups. cam-lam used to sell a strobe suitable for the Varitronic.

Mines a Draper £20 job that worked fine so who knows if a special one is required.

On the other hand you could be seeing your stator/cdi breaking down

make another timing mark directley opposite the one on the flywheel,, ie,, if timing mark is 12 oclock, make one at 6 oclock,,, re strobe and as if like magic you,ll see the new timing mark

The spark is breaking down under load...possibly due to misalignment between stator pickup and flywheel firing point.


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