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Newtronic Timing
Posted: Sat May 15, 2010 10:12 am
by robert campbell
So, the Newtrnic is on "gypsy" but not started yet. Funny thought came to my mind last night that I have never done on a motorcycle engine. Use a timing light!
So I plan to set the left timing marks as close is I can to the light chopper passing through the light. Accomplished by twisting the plate on the three mounting screws. Similar to turning a distrubuter for a car to line up the number one cyclinder to the rotor. So if it starts up and will run, at a low idle, I will twist the plate for the left cyclinder until I line the timing marks togther and then secure the plate.
Then do the same thing with the indiividual adjustments for the center and right cyclinder.
I am asuming that when the two timing marks line up you are a the proper 24 degrees BTDC that it says in my owners manual?
Am I all wet or on the right track?
Rob
Posted: Sat May 15, 2010 3:08 pm
by h2okettle
Hi Rob... That is the way I did mine and it works great.. I just lined up the marks in the lower window on all 3 and locked it down.. I pulled the points cover once after about 20K miles to check the timing with the light again and it was still perfect.. Its been over 30K miles since I installed it and the bike fires up immediately every time..
I am sure there are more scientific ways to do it, but I have never had a problem with doing it this way and I have put over 100K miles on the bike.
Good luck with your bike...
Allen.... Heavy smoker.... GT brand !!
Posted: Sat May 15, 2010 5:33 pm
by Triplerocky
I did the same on my GT380 with a brand new Newtronic....only 1000 km since installed

but never missed a beat.
Posted: Sat May 15, 2010 5:55 pm
by robert campbell
THANKS GUYS!!! It seemed so simple it must be wrong!
Rob
Posted: Sat May 15, 2010 7:38 pm
by tz375
The only thing to watch out for with the timing 'disk" is that it has a certain amount of free play on the drive pin.
It is worth checking that the lines are actually at 24 degrees. If not adjust the timing plate. If it's all OK, just use teh marks and timing light
Posted: Sat May 15, 2010 9:57 pm
by robert campbell
tz375 wrote:The only thing to watch out for with the timing 'disk" is that it has a certain amount of free play on the drive pin.
It is worth checking that the lines are actually at 24 degrees. If not adjust the timing plate. If it's all OK, just use teh marks and timing light
I would agree with that! What is the distance from TDC to 24 degrees before? I have not seen that in print.
Rob
Posted: Sun May 16, 2010 6:46 am
by Coyote
Just multiply the numbers given (mm) by .03937 to obtain thousanths.
i.e. 3.37 x .03937 = .1326 Then round off to nearest 3 place. -- .133
Posted: Sun May 16, 2010 9:54 am
by robert campbell
Ask and shall recieve! Thanks Coyote! So is the 3.63 MM and the 3.42 MM for my 1975 GT-750M from a dial indicator in the spark plug hole to the top of the piston or a distance from the top of the cyclinder to the top of the piston? I have seen picturs of a fixture in the spark plug hole? Seems to make sense to use the spark plug hole on a torqued down assembly.
I am assume that is what those columns of measurements are? Mili- meters for the distance before TDC for timing?
Rob
Posted: Sun May 16, 2010 5:04 pm
by robert campbell
Alrighty then! She runs great, but not without a bit of consternation! Rob learned the hard way why the instructions say do not time it outside in the light..... Tried to and it would not even spark the spark plug or light the timing light..... I thought the reason we needed to be inside was it was hard to see the timing light!!
Duh! The light chopper needs to be in darkness to work. We put the points cover on, and bingo, it ran great! So into a darkened garage stall and no problemo setting the timing!
She runs great now!!! Newtronic is pretty much plug and play. Once the left cyclinder was set the other two light choppers were almost dead on as preset by Newtronic.
Great stuff!!
Rob