130202 5HP Engine Need to get her running

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Brewha

New Member
#1
#1



I'm attempting to get my very first motorcycle running again. I learned to ride this bike somewhere around 1984 and I don't think it's run in at least 15 yrs.

I've cleaned out the tank and gone through the carb. I just bought a brand new plug and found no spark. If I grab the wire and pull the recoil, I can feel a weak shock. But, I can't see a spark if I ground the plug and pull it over. Here's what's under the recoil:


I have experience with small gas engines that have a magnetized flywheel and coil like I see here. On those, that's all there is to the ignition. And, there's really nothing to tweak or fix. I've taken some emery cloth to the flywheel and shined it up a bit. The gap between the mag and flywheel looks good. Is there anything else I can do to get a good spark jumping?
 
Yellowhand

Yellowhand

#2
#2
The gap between the flywheel and magneto should be .012"...that's roughly three sheets of paper thickness...the gap closes quickly when corrosion builds up on the flywheel and the bottom of the magneto...

...and Briggs Magnetron magnetos develop little or no current below 350 rpms...give the starter rope a brisk pull when testing the ignition.
 
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Brewha

New Member
#4
#4
Man, that's weird that there's points and condenser too. I kinda suspected that since there is a wire running from the coil that I hadn't seen before. Thanks, though! I just didn't want to pull the flywheel only to find nothing back there. I'll report back with the results.
 
DreyeIce

DreyeIce

New Member
#5
#5
i have the same motor, and it had weak to no spark, i pulled the flywheel, took of the points cover, cleaned it out with brake cleaner quick, got some black 1200grit sandpaper (like you would use to wet-sand a car)

i turned the crank till the points opened up, slid in the paper, and closed the points on the paper, i gently slid the paper back and forth a few times, pulled it out (while still closed), opened the points, gave em a shot of brake cleaner, then re-installed the points cover with a bead of silicone around it, gapped the coil and it sparks like crazy now :)
 
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Brewha

New Member
#6
#6
Wahoo! A little emery cloth on the points was all she needed! I don't even have the recoil on her yet. I just positioned the magnet right before the magneto and gave the flywheel a quick flip with my hand. A NICE BLUE SPARK!!

If I had a muffler for this thing, I'd take her out to the garage right now and see if she'd fire. But, in the name of peace keeping with the neighbors, I'll just wait til tomorrow. Thanks for the advice!
 
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Brewha

New Member
#7
#7
I got a couple of pops and backfires with gas in the carb, but she's not running. I suspect the compression is low. My first compression test showed 50psi. After dumping a little oil down the plug hole, I got 90 psi. I'm guessing my rings are shot. :( Looks like it'll take a little more work to get her going. Oh well, at least I got spark.
 
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Brewha

New Member
#9
#9
So, I found a few rebuild kits. Here's one on the bay:
Rebuild kit

I found a couple of other online retailers too. Looks like prices are anywhere from 40-80 bucks. It's odd to me that they all come with new pistons. Why not just replace the rings? Do the pistons burn up on these things? Or do they just think that since the engine is apart you might as well replace the piston too?
 
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MAX3

New Member
#10
#10
Brewha said:
So, I found a few rebuild kits. Here's one on the bay:
Rebuild kit

I found a couple of other online retailers too. Looks like prices are anywhere from 40-80 bucks. It's odd to me that they all come with new pistons. Why not just replace the rings? Do the pistons burn up on these things? Or do they just think that since the engine is apart you might as well replace the piston too?
Click to expand...
I rebuild one B$S with used rings from one lawn mower engine and it still runs good.


Also, I just retrofitted the coil with one lawn mower coil and got rid of the point and condensor weeks ago. It run great.



 
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Ejd57

New Member
#11
#11
i have this engine

um well the condenser goes bad and the coil gets weak on these you need to pull the condenser off and coil and replace them then you should get a 9-12v charge right off of the condenser after you replace those be careful i grabbed the spark once and turned it over i all most had a heart attack it hurt a lot and about the rings yea there are shot if in had a lil or no oil for that long they will rot and go bad all you half to is get the rings not a whole rebuild
 
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Brewha

New Member
#13
#13
The key is good and so is the spark. At a minimum, it'll need new rings. But, it may need a complete rebuild.

Regardless, it's not my project anymore. This engine starts it's cross country trek tomorrow. Next week, it'll be on the Pacific coast. Thanks for the advice, but I won't be needing it anymore.
 
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