|
|
Post by zbillz on Sept 9, 2023 16:44:54 GMT -5
Hi All,
New here.
Son just picked a 1978 Sr500...kind of a basket case.
Can get it started. Seems to get one fire then nothing, with starting fluid.
Filled carb with gas,same problem.
Has spark but it seems awfully weak and I think this is the issue.
Does not have a battery and it has some sort if aftermarket ignition and rectifier. Checked and respliced all connections to ignntn system, same issue.
What would cause a weak spark, Can barely see it when kicking.
I will post pictures of igniting setup tonight.
Thanks!
|
|
|
|
Post by gcrank1 on Sept 9, 2023 19:00:06 GMT -5
The SR alt stator has its own ignition coil (think: like a magneto) as well as the charging coils, thus the charging and all but ignition when running is separate, that includes the solid state rectifier. Point being, dont get sidetracked from the ignition issue by the 'charging stuff'.
It is not unheard of for the old stator to be poor to bad this make weak to no spark. Stators can be 'rewound' but the SR stator should only be done by someone familiar with them. Idk who or where any more.
Also note that not all SR stators are interchangeable, though iirc?, if you have the matching stator and rotor you are ok.
I believe there is a proper 'air gap' required between the rotor and pick-up coil?
Its been a while......That is all Ive got for now
|
|
|
|
Post by zbillz on Sept 9, 2023 21:16:16 GMT -5
Can the gap between the rotor and pickup coil cause a weak spark?
Can the gap be adjusted?
|
|
|
|
Post by stevep on Sept 10, 2023 6:14:10 GMT -5
 The gap is fairly critical. Adjusted by undoing the central screw holding the pulser coil in place. Caution if the screw appears corroded since they can shear off quite easily (!) Reading at A should be between 0.8 and 1.0 mm (Backfire may result below 0.7mm) Reading at B should be between 0.7 and 0.9 mm (Hard starting above 1.0 mm) Don't forget that the visual appearance of a spark from a CDI can be misleading since they can tend to look weak. However, everything Gcrank said about the early bikes needing rewinds by now is correct. Custom Rewind of Forestdale, Alabama is one source if you are stateside. Rex's Speedshop is another if you are in the UK. Don't whatever you do, have it done by anyone called Rick. (See thread below.) Don't know if this thread will be of any use? www.dotheton.com/index.php?threads/help-me-find-spark-on-my-sr500.75914/ |
|
