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1971 SL70 & 76 XR75 No Spark

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I have a SL70 and XR75 with no spark. I have power, juice, electricity, (etc...) all the way to the coil, (tested with test light) and no spark coming out. I replaced the coil on the SL with a used one but still no spark. What am I missing?? What shoud I check??

Thanks,

David

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Nice bikes, got any pics. If you are not familiar with points then you need to be. It is kind of a PITA on these bikes as they are behind the flywheel.

Clean and or replace them and put a new plug in and you should be good to go.

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Your bike has point ignition. Here's what I recommend for anyone having problems getting proper spark with point ignition bikes. [i'm beginning to think this should really be a sticky as I feel like I'm typing this up almost every day for people that are having trouble getting spark]:

1)Remove the left hand side engine side cover and look through the cut-outs on the flywheel and you'll see the points, you hay need to turn the flywheel a bit. Now use a small point file [if you don't have one you can use a small, thin strip of sandpaper folded over so the "sand" part is on the top AND on the bottom] and gently isert it between the point contacts and file them just enough so that both contacts look shiny. [if you're using sandpaper, you'll need to open the points with a small screwdriver, push the sandpaper in between the contacts, and then drag the paper back out with the pressure of the points spring squeezing the sandpaper]This will be easier with the flywheel off, but you can still do it with it on and may take a lot of sanding before they are look nice and shiny.

2)Now you want to clean the contacts. Take a piece of white printer paper and cut 2 or 3, 1/4 inch strips. Now once agin open up the points and slide the thin strip of paper between the contacts, let the pressure of the point spring squeeze the paper, then drag the paper back out. Repeat this 7 or 8 times, tearing off the end of the paper that you just dragged through the dirty contacts, so you have a nice clean strip of paper each time.

3) Set point gap. Gap should be .012~.016

4) Check for spark [make sure you have a new spark plug or know that the one you are using works] If no spark, use the paper again 2 or three times just to make sure they are free of debris.

Still no voltage? Get back to me and I'll explain how to test the stator coil.

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Thanks for the replys guys!

I have filed the points with no luck. But after reading threads, and posts on this forum, have decided to start with the basics and replace the points and condensers on both of my bikes. It was frustrating because I kind of know that coils don't go bad very often, I was just hoping it was a quick fix.

I ordered a flywheel puller and points that I hope to recieve later this week.

Thanks again for you help and I will post my results.

David

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Take a minute to remove the spark plug boot, cut the outer plug wire insulation back a 1/4" or so, carefully remove the insulation to have fresh bare wire, and then see if you get spark. Sometimes, the plug boot will go bad, they are usually easily replacable for around $5-$6. The Standard NGK plug boot is part #LD05F.

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Your bike has point ignition. Here's what I recommend for anyone having problems getting proper spark with point ignition bikes. [i'm beginning to think this should really be a sticky as I feel like I'm typing this up almost every day for people that are having trouble getting spark]:

1)Remove the left hand side engine side cover and look through the cut-outs on the flywheel and you'll see the points, you hay need to turn the flywheel a bit. Now use a small point file [if you don't have one you can use a small, thin strip of sandpaper folded over so the "sand" part is on the top AND on the bottom] and gently isert it between the point contacts and file them just enough so that both contacts look shiny. [if you're using sandpaper, you'll need to open the points with a small screwdriver, push the sandpaper in between the contacts, and then drag the paper back out with the pressure of the points spring squeezing the sandpaper]This will be easier with the flywheel off, but you can still do it with it on and may take a lot of sanding before they are look nice and shiny.

2)Now you want to clean the contacts. Take a piece of white printer paper and cut 2 or 3, 1/4 inch strips. Now once agin open up the points and slide the thin strip of paper between the contacts, let the pressure of the point spring squeeze the paper, then drag the paper back out. Repeat this 7 or 8 times, tearing off the end of the paper that you just dragged through the dirty contacts, so you have a nice clean strip of paper each time.

3) Set point gap. Gap should be .012~.016

4) Check for spark [make sure you have a new spark plug or know that the one you are using works] If no spark, use the paper again 2 or three times just to make sure they are free of debris.

Still no voltage? Get back to me and I'll explain how to test the stator coil.

I am having a similar problem with my XR75. Could please post how to test the stator? Thanks

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I replaced points in both of the Honda's and it fixed the problem!!

I had put a test light on the wire leading to the coil. I was getting juice to the coil, but no spark. I assumed the points were good because of the power up to the coil. I didn't take in consideration the opening and closing of the points to create spark.

So after reading replys on this, and posts on other threads, I decided to try the points. The electrical system on these little bikes are pretty simple so I started with the points.

Thanks for the replies, and I hope this has helped someone else!

Thanks again!!!

:smirk:

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