Suzuki 2 Strokes

New here! Great forum you guys have here! Seems to be a wealth of knowledge on these old 2-Strokes!!

So heres the breakdown - Im finishing up a restore/cafe build on a 1972 GT380. Im on my final step - and that is installing the new electronic ignition (Newtronic) and timing the bike accordingly.

First problem I encountered was dismounting the retianing nut on the timing cam without sheering off the nylong gear. Ive read around here in the forum some things that state you need to remove the entire right case cover and the whole assemply pulls out of the case. Is this correct?

Second part of the question is, once I was removed the case cover, timing the bike for the new ignition... I am aware that I will need to align the timing base plate with the punched mark on the gear, however since I am not using the points, what should be the process for setting this up with the electronic system?

I appreciate your help and look forward to hopefully contributing to the forums!!

Any guidance would be greatly appreciated!

John

Hi and welcome

Have you already removed the clutch cover? You should retain the 3-legged "timing marker" that has L, C, and R stamped on it, but just discard the actual points cam and replace the cam with the Newtronics gizmo that breaks the light beams in the sensors.

When it comes to timing it up, set each of the sensors in the middle of their travel (so you can adjust them either way) then if I remember right you can use the LED lights on the Newtronics box to get the timing close statically (using the L / C / R marks).

To get it REALLY accurate, you should use a dial gauge to establish the true firing point, scribe lines on the timing marker, then strobe to those marks with the engine running .... but the L / C / R marks are usually close enough.

Good luck with it.

Thanks a lot! Thats what I had in mind, I just wanted to confirm it before making some foolish mistakes. Do you recon the LED indicators will give me a reading accurate enough to run the bike safely and efficiently?

The LEDs will give you a good static timing set-up ... however, the small problem with the triples is that the L/C/R markings are NOT actually accurate timing marks, they are just assembly marks to get the timing in the ballpark at the factory when the cases are being put together on the production line. Then the settings need fine-tuning, ideally using a dial gauge.

That said, I did borrow a dial gauge to set the timing "properly" on my own 380. The L/C/R marks measured at around 1.9mm BTDC. The correct timing for my M model is 2.25mm BTDC. So I scribed some lines corresponding to the correct timing and strobed to those markings.

Guess what? The bike didn't like it, it gave me a little pinking / detonation. So I pulled it back to the L/C/R timing marks (1.9mm BTDC), and the bike runs sweet as you like, with not a trace of detonation and no effect on performance.

The upshot is, it helps to know how accurate the L/C/R marks are on your engine, then you know what you're dealing with. These marks are good enough to get the engine up and running, but if you're gonna ride long and hard, it's good to know exactly what your timing is. Of course once you've set the Newtronics, the timing should never change.

These engines (in standard tune) are not very sensitive to timing variation, so I feel it's better to err slightly on the retarded side than risk detonation through an over-advanced spark, and maybe a holed piston.

Sweet!! Thanks a lot for the input Craig. Very helpful and very encouraging. I think Ive been psyching myself out. Im gonna give it a go this weekend.

Thanks again!

with the LEDs...is is that when BOTH the led for the piston you are aligning and the piston before it LIGHT TOGETHER is the fire point?

thanks

MJ in Beirut