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Agusto/ignition - any ideas?

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

Agusto/ignition - any ideas?

Postby Solid Air » Fri Sep 06, 2019 11:07 pm

Not been happy with high EGT readings recently on my Quattrini. Thought it might just be jetting as I've just changed the exhaust but despite trying many combinations of jets, needles, slides etc no joy so thought I'd look at the ignition.

During riding, just pass 1/2 throttle the engine starts stuttering, the heat increases quickly and is not rideable in the range above that, worsening over the past week.

Have just splashed out on a buzzwangle so used that to check TDC and mark up 24° & 15°. Started the engine and the timing arrow was only strobing at about 22° @ idle and 18° @ 6000 revs.

Swapped the Agusto for a new spare, restrobed but no difference.

Checked the pick-up, had a reading of 95 ohms. Swapped it for a new BGM item but that read the same and no difference on the bench with the strobe.

Disconnected the Agusto and restrobed, that gave 24° increasing to about 28° @ 6000 revs.

Using a BGM stator and flywheel for sometime now with no problems.

Options at the moment are; set to static timing of 17°, try a 3rd Agusto (will also give Replay a call) or replace with an M-Tech.

Any ideas or opinions?

Cheers, Mark
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Re: Agusto/ignition - any ideas?

Postby CHRIS in MARGATE » Sat Sep 07, 2019 8:31 am

Sounds like stator if it's advancing. My Agusto 6000 goes from a very accurate 23.5 at tickover to 16 at 6000 rpm
7.5 degrees retard.
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Re: Agusto/ignition - any ideas?

Postby Solid Air » Sat Sep 07, 2019 9:32 am

Cheers Chris, I've got a spare which I'm going to try.
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Re: Agusto/ignition - any ideas?

Postby Adam_Winstone » Sat Sep 07, 2019 6:45 pm

"Disconnected the Agusto and restrobed, that gave 24° increasing to about 28° @ 6000 revs.", this suggests that the stator is causing the issue, rather than the Agusto. Could also be combination of stator and flywheel.
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Re: Agusto/ignition - any ideas?

Postby Paul_from_Thornbury » Tue Sep 10, 2019 9:09 am

Mark, on my RT195 I used to run an Agusto 7000 with my BGM Stator and Reedspeed LUKAS CDI until my pick up failed. I switched to my external pick up but it wouldn't start. On speaking with Anthony Tambs he advised his pickups were only compatible with Krytonic units. I removed the Agusto and set at a fixed 17 degrees. I have to say the improved spark from the external pick up and DC CDI improved the low end running such that the retard unit wasn't needed.
I run an external pick up now on my TS1 Winter Model with an Anthony Tambs DC CDI, again, 17 degrees before TDC is perfect around town and at higfher speeds.
The DC CDI's/Coil set ups transform the engine.
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Re: Agusto/ignition - any ideas?

Postby Solid Air » Tue Sep 10, 2019 11:09 am

Cheers Paul and Adam. I might have found the problem. The BGM flywheel has been running up against the pick-up scoring the resin(?) magnet, which is going to affect the pick-up signal I would imagine. It's strange because the scouring is pretty much all round the inner flywheel surface apart from two small areas of 10-15mm, directly opposite each other. I have checked the crank and that seems solid in the bearing so not quite sure why the gaps are there, not completely round magnet maybe?
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Re: Agusto/ignition - any ideas?

Postby Knowledge » Tue Sep 10, 2019 1:12 pm

On Anthony Tambs Facebook site he often talks about issues with incorrectly located pick-ups.

He mentions both the height of the pick-up (and supplies shims to go beneath the pick-up on his own six pole stators) and the air-gap between the pick-up and the magnets. Anthony supplied his own flywheels, which have an extra couple of slits cut into them to allow you to measure the air gap.

He's a clever guy, no mistake. It is a shame he doesn't post on the forum too often, as people who don't do Facebook don't get to learn from his wise words.

(BTW, I like the sound of the benefits of the DC CDI. I might go for that)
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Re: Agusto/ignition - any ideas?

Postby dickie » Tue Sep 10, 2019 2:19 pm

Knowledge wrote:On Anthony Tambs Facebook site he often talks about issues with incorrectly located pick-ups.

He mentions both the height of the pick-up (and supplies shims to go beneath the pick-up on his own six pole stators) and the air-gap between the pick-up and the magnets. Anthony supplied his own flywheels, which have an extra couple of slits cut into them to allow you to measure the air gap.

He's a clever guy, no mistake. It is a shame he doesn't post on the forum too often, as people who don't do Facebook don't get to learn from his wise words.

(BTW, I like the sound of the benefits of the DC CDI. I might go for that)


I'm running DC CDI on both of mine. Strong spark at almost zero rpm. No LT coil which is the Achilles heel of lambretta ignition in my opinion. Every motorcycle produced uses this basis and other than on lambrettas, I don't think I've ever had ignition trouble.
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