no spark 1970 T350

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russt
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Suzuki 2-Strokes: 1970 Suzuki T350

no spark 1970 T350

Post by russt »

I have a 1970 Suzuki T350 with no spark plug spark. All lights and blinkers work. Ignition seems to be ok. Battery is 12v 7 amp and seems to be charging to over 12V. I cleaned the points and the coils are about 12 years old. The bike has been sitting in the weather for about 10 years. Any suggestions on what I could do to get it to spark? thanks.
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Re: no spark 1970 T350

Post by titan performance »

Is there power at the points?
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Craig380
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Re: no spark 1970 T350

Post by Craig380 »

As Titan said above, check that you've got 12V at the breaker points. Remove the points cover and with ignition on & kill switch on, flick the breaker points open with a small screwdriver or similar. Do you see a spark at the points? If yes, the problem is in the ignition coils, HT leads, plug caps, spark plugs or the wiring from the points to the coils.

If you don't see a spark at the breaker points, you'll need to check all the ignition-related wiring with a meter. Also, you mentioned you have cleaned the points - did you use a file or wet&dry abrasive paper to do that? If so, that can kill the points - they have a coating on the mating faces of the points which if damaged, means no spark.

Let us know what you find and we can help narrow it down.
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Re: no spark 1970 T350

Post by jabcb »

Also check the battery voltage when the ignition is on. A shot battery can show 12V with no load but then drop enough with load that you don’t get enough voltage to get a spark.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

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russt
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Suzuki 2-Strokes: 1970 Suzuki T350

Re: no spark 1970 T350

Post by russt »

I do have a spark at the points when they are open and the ignition is on. I am also getting 12v at the points. I have ordered spark plug wires and a new battery. I will see what happens when they arrive and I can hook them up. The throttle cord just broke on me so I will have to get a new throttle assembly. Thanks for the suggestions and let me know if you have any other ideas.
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Re: no spark 1970 T350

Post by sportston »

While replacing the plug leads make sure you put new plug caps on the end of the leads too
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Re: no spark 1970 T350

Post by Craig380 »

sportston wrote:While replacing the plug leads make sure you put new plug caps on the end of the leads too
+1 to this. To eliminate problems with plug caps, I used to use non-resistor caps on my 380. When you do get the bike running (and you will if you've got 12V at the points), I would recommend installing the Iridium equivalent spark plug too. They never need regapping, never foul and do give sharper running on the road.

A quick thought - remove the plug caps and hold the HT lead near the cylinder head (use gloves). Turn the engine over, ignition on. Do you get a spark from the HT lead to the head?
1976 GT380 - wounded by me, and sold on
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2017 SV650 AL7 - naked and unashamed
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russt
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Suzuki 2-Strokes: 1970 Suzuki T350

Re: no spark 1970 T350

Post by russt »

Does the length of the spark plug wire matter? How many volts should I be getting from the wires(Orange/Black, Orange/White) that plug into the coils? I'm getting around 5.5 - 6 ohms when I test from the positive to negative side of the coils. I'm getting 9.5 - 10ohms when I test from either the positive or negative side of the coil to the center of the coil.
I did get new spark plug boots that come already attached to the new wires.
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Re: no spark 1970 T350

Post by sportston »

Length of plug wire shouldn't really make much difference. In theory the longer the lead is, the greater the resistance is, but.... In reality, on a good quality copper core plug lead a few extra inches doesn't make much difference. However, a long lead can be more likely to get damaged if it is allowed to rub against other components (a chafed lead can track out to earth).
What is important on old motorcycles is the ends of the lead. Water can get in and cause corrosion which will lead to arcing and a bad spark. If you ever come across the ends of a lead looking green and powdery you must cut the lead back until you get to fresh bright copper and make a new watertight connection with a plug cap or coil that does not have any signs of corrosion on it.
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russt
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Suzuki 2-Strokes: 1970 Suzuki T350

Re: no spark 1970 T350

Post by russt »

Well still no spark with new wires, boots and battery. :roll: Any other help would be greatly appreciated. Thanks for all the replies thus far, they have really helped.
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Re: no spark 1970 T350

Post by dollydog »

have you got aftermarket coils on this bike? replace with known, good suzuki coils.
are the coils properly earthed? or as you say, grounded? :D they need to be.
are the coils wired properly? orange wires to +ve side, via the kill switch.
black wire -ve on one coil, white wire on -ve the other.
does the kill switch work properly? test with continuity tester.
do the spark plugs actually work? just because they are new means nothing.
look between the points. i've known a tiny speck of rizla paper in there to stop a spark.
[google: setting points using rizla papers] :D always look for an easy solution, it will be.
cheers, dd.
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GT250 big bang road registered. Both pistons fire the same time. USD forks.
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russt
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Suzuki 2-Strokes: 1970 Suzuki T350

Re: no spark 1970 T350

Post by russt »

dollydog thanks for the reply:
1) The coils are a EMIGO brand that are supposed to be universal. The wires are new but the coils are probably 12 or more years old.
2) I have installed the wiring to the coils as you have stated and the battery is new.
3) I have rechecked the points and I am getting 12V to each one. I also get a spark when the points are open when I place a flat head screwdriver to them. I cleaned them with sandpaper before I found this forum :(
4) I have checked the spark plugs with a meter and they are getting the current through them.
5) The headlight works, my blinkers come on but one will not blink. The brake light works.

If I order new coils, do you have any ideas as to what brand would work?
How do I get to and check the stator? or would it be, or not be, a problem?
How do I check the kill switch?
Thanks again!!

This is all new to me and I am not a mechanic. :D
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Re: no spark 1970 T350

Post by jabcb »

The capacitors could be bad.

The sandpaper has most likely left some crud on the points. Use something like a clean new 3x5 index card to clean the points. When the points are closed, open them with a screwdriver, insert the card, close the points, then pull the card out to clean the points. Repeat until card comes out clean.

You measured 5.5 ~ 6 ohms for the coil primary. This is somewhat higher that the stock coils.
You measured 9.5 ~ 10 ohms for the coil secondary. Did you mean 9.5k ~10k ohms?

If you meant 9.5 ~ 10 ohms for the coil secondary, then the coils are shot.
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
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Re: no spark 1970 T350

Post by dollydog »

hi mate, first of all, [1] as jabcb says, your secondary reading should be about 1000 times what you've got. offhand, i seem to remember my primaries are about 4.3 ohms.
[2] if you've used sandpaper on the points, i would replace them at the first instance, depending how scratched they are.
[3] get the 2 wires from the kill switch [orange and orange/white], use a continuity tester. you should get continuity when the kill switch is on run. when it's off you shouldn't get a circuit.
[4] sounds like the stator is ok as it's charging, so leave it.
[5] get some suzuki coils, gt185, gt250, t250, t350, they are all the same and there's plenty of them about. if you want to use other brands, ok, but get a similar resistance to the suzuki coils.
[6] indicator - change bulb :D
cheers, dd.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
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akendall1966
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Re: no spark 1970 T350

Post by akendall1966 »

When you measured the coils, this was disconnected from the rest of the wiring no plug caps? This shouldn't really effect the measurement of the secondary which if your measurement are true indicate the coils are shorted internally

Just in case your not aware if you replace the coils and do go aftermarket remember coils for CDI are different to point/tci ignition make sure you get the correct type as the primary and secondary windings are different. CDI coils will likely burn out the primary in a points system particularly, sat ignition on not running where the engine has come to rest with the points closed.
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