Advance timing and revs vs power

[paulnobodyimportant]

I understand the downside of static timing and the advantages of the bolt on boxes, like M Tech or Augusto, to move the timing more to TDC as the revs increase. However, with one of these boxes, as the revs increase to say 7000rpm and the strobed timing is say 16 degrees before TDC are we now losing power at the expense of greater cooling.

I say this as last October, I de coked my TS1, put in new clutch, rings and reed petals and for the first time put on an Augusto 7000, with static timing at 24 degrees. It strobes back to around 16 degrees at 7000rpm. However, I have now done around 400 miles since the re-build and it doesn’t seem to have that grin factor anymore, or that sudden kickback in 3rd gear as you hit the power band. So I can only assume that it is the Augusto unit that has caused this effect. So might play around with the static timing etc.

Got an M Tech unit for another Lambretta and just ordered a Ky Tronic for another one, so I will see how they fare.

Just wondering

[Monty]

Im having the same problem with an M Tech although on a Mugello 185 with a JL Snail. Changing into 4th it drops out of the pipe power band and the slower revs goes back towards 20ish degrees and has to pick up revs and power again. Im looking at going to one of the smaller retard settings so its always round 18-19 and retards to 16 15 at full chat. A mate reckons his is so much smoother with the M Tech but I think he is not seeing the benefit of the expansion pipe. I must admit my Imola setup with an Augusto 7000 is smoother, has lost the kick but its not like hitting a brick wall when going into 4th as like the M Tech
.

[paulnobodyimportant]

Yes Monty,

I've been reading your thread, which prompted me to post this one. I've got a M Tech on a Monza, and just had it re-dynod and its lost 1 bhp. (19.5 down to 18.5) But I've yet to have it out on the road to see what it feel like. But doing the plug chops before the dyno, it felt very good when it came to the poke factor. But a good ride isn't doing 1/2 mile runs doing the chops on the Skipton Bypass.

[jonashford]

I use a kytronic no problems so far. If ur dropping out of the rev range when changing in to 4th, lower ur gearing or fit a cyclone gearbox!

[daveh]

I agree that the Augusto for me seemed to reduce the "grin factor" ...I am sure it is a matter of preference, tune, gearing etc....but I have taken my Augusto off...and the grin has returned

[fastfrog]

I'm not sure that 16° at 7000 rpm on a >200cc engine sounds right.... Have you tried 19°?? leave 16° after 8500

[Special X]

All other engine applications advance the spark as the revs rise because as the engine spins faster the burn is effectively retarded. Retarding the spark as the revs rise is making the engine safer but killing the power as the burn (whrich takes a finite time) is finishing later and the retard device is making it start later which will exacerbate the problem.

[eden]

What Special X said


I have to run static 16 degrees on my cast 245.
one day ill try variable ignition on it, it would help it pull between 5,5 and 6k rpm which is its only flat spot.

[boris]

I understand the downside of static timing and the advantages of the bolt on boxes, like M Tech or Augusto, to move the timing more to TDC as the revs increase. However, with one of these boxes, as the revs increase to say 7000rpm and the strobed timing is say 16 degrees before TDC are we now losing power at the expense of greater cooling.

I say this as last October, I de coked my TS1, put in new clutch, rings and reed petals and for the first time put on an Augusto 7000, with static timing at 24 degrees. It strobes back to around 16 degrees at 7000rpm. However, I have now done around 400 miles since the re-build and it doesn’t seem to have that grin factor anymore, or that sudden kickback in 3rd gear as you hit the power band. So I can only assume that it is the Augusto unit that has caused this effect. So might play around with the static timing etc.

Got an M Tech unit for another Lambretta and just ordered a Ky Tronic for another one, so I will see how they fare.

Just wondering

My RT kit was a disappointment.
Then I put the kytronic on it.
Slowed it down even more.
Felt like I was towing another lamy around with big daddy on it.

Sent from my HTC Sensation Z710e using Tapatalk

[Lamaddict]

If it feels like it's not working, get a strobe on the flywheel and try and see how it's retarding.

I run an Agusto on my SIL MB RT Piston 215 set, it's a great reliable engine and the Agusto works well but I'm also building an RB250 and I'll be leaving the timing static. I don't fancy cruising and potential building up heat on a highly tuned engine due to the timing at somewhere around 20 degrees, for example. I believe those Kytronic set ups can be mapped but I'm still weary. The other obvious thing is get your timing sorted either way and then play with the carb settings.