The stock coils are pretty meager. The ability to fire the plugs depends on a lot of things including the condition of the points, coil to coil variations, the total HT resistance & conditions of the plugs.
For example, the T250/T350 have permanent magnet alternators. Some of them will start & run fine without a battery, while others will not start without a battery with a pretty good charge. The difference between the bikes is just how all the pluses & minuses add up for the electrical & ignition systems.
Last year my 71 T350 was running on only one cylinder. I dressed the offending points with a few swipes of a points file & then cleaned them. That's all it took to get both cylinders running good.
(For others reading this post, you should never run a T250/T350 without a battery. The bikes don't have a voltage regulator & you will burn out the lights if you don't have a battery.)
I don't know how much resistance is added by the carbon HT wires.
Depending on how all of the pluses & minuses add up, you may be fine with resistance plugs, resistance wires & resistance caps. Might be perfectly fine with new points, but then cause you problems later as the points age.
Suzuki GT380 timing.
Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan
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jabcb
- Moto GP
- Posts: 4317
- Joined: Mon Dec 13, 2010 4:32 pm
- Country: USA
- Suzuki 2-Strokes: 69 T350 thru 75 GT750
- Location: southwestern Pennsylvania
Re: Suzuki GT380 timing.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more
Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
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bpeck27
- On the street
- Posts: 24
- Joined: Sun Nov 30, 2014 3:41 pm
- Country: USA
- Suzuki 2-Strokes: GT550, TS400
- Location: New Jersey, USA
Re: Suzuki GT380 timing.
I use an alternate method of setting the timing on my GT550 that I learned from my go-kart racing days: You'll need a piston stop, which you can make by beating the porcelain and center electrode out of an old spark plug, grinding off the side electrode, then installing a bolt through the center hole that extends about an inch past the plug base. You'll also need a degree wheel, which you can make out of a cheap plastic protractor. I attach the degree wheel to the alternator side of the crank, and a pointer, made out of piece of soft wire, to one of the cover bolts.
With the piston stop installed, find top dead center for that cylinder by setting the degree wheel so it reads the same angle from zero when the piston touches the stop in both rotation directions. Then remove the stop, connect a continuity tester across the points for that cylinder, and rotate the engine in the forward direction until the points open. On the 550, the points should open at 24 degrees before TDC. The setting for other models can be found in the tune-up specs.
I use an audible continuity tester because I find it a lot easier to watch the degree wheel while listening for a tone to stop rather than watching for a light to go off.
I use this method because (1) it's familiar to me, (2) I already had the tools, and (3) it saved me the cost of a dial indicator. And, as somebody else said, how do you get the dial indicator in the center cylinder with the frame in the way?
With the piston stop installed, find top dead center for that cylinder by setting the degree wheel so it reads the same angle from zero when the piston touches the stop in both rotation directions. Then remove the stop, connect a continuity tester across the points for that cylinder, and rotate the engine in the forward direction until the points open. On the 550, the points should open at 24 degrees before TDC. The setting for other models can be found in the tune-up specs.
I use an audible continuity tester because I find it a lot easier to watch the degree wheel while listening for a tone to stop rather than watching for a light to go off.
I use this method because (1) it's familiar to me, (2) I already had the tools, and (3) it saved me the cost of a dial indicator. And, as somebody else said, how do you get the dial indicator in the center cylinder with the frame in the way?
