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NO Spark on R50/2

Posted: Sat Jun 05, 2021 1:30 pm
by bigdave
Working on a 1965 R50/2 that I picked up last fall. Replaced the slingers and did lots of other work on her. Heads were done by Randy Long to fix exhaust threads. He also installed new guides and repaired a spark plug hole that had a small crack. Valves are not original, but are OK, as are seats.
Now I am trying to get her to run. Rotor can be picked up by a wrench and lines up with notch in magneto when flywheel is at the S. Points open at the S. New Emerald Isle coil. Compression is 70psi on both sides. Cylinders were honed and new rings were installed.
When I kick it over, there is a weak spark on a grounded plug. Never got a spark to jump the gap on the magneto if I removed the plug caps when kicked.
Pictures may show what I am doing wrong (not the first time). I am open to suggestions and comments.

Re: NO Spark on R50/2

Posted: Sat Jun 05, 2021 2:03 pm
by schrader7032
What is the gap at the safety gaps? Looks more than the 10/11mm required. It's been a while since I installed my Emerald Isle coil...is it properly grounded? Is the condenser good...maybe try a new one.

Re: NO Spark on R50/2

Posted: Sat Jun 05, 2021 4:25 pm
by jwonder
bigdave wrote:
Sat Jun 05, 2021 1:30 pm
When I kick it over, there is a weak spark on a grounded plug.
In my mind if you have any spark on the plug when kicking it you are good. Does it spark consistently or intermittently? Remember it’s a magneto and your not spinning it fast on the Kickstarter.

I would be looking elsewhere than the electrics if it was me. I would be making sure you are getting fuel and I would spray a bit of starting fluid in it to see if it fires. I would not be surprised if it did.

Re: NO Spark on R50/2

Posted: Sat Jun 05, 2021 4:43 pm
by Andrew
Hi, there are many reasons why its not running .... the compression is not ideal ,70psi is not very high but that might be due to dry cylinders i.e no fuel getting in to help seal the air to compress , suggestion : depress the tickle plunger on both carbs to near flooding , open the throttle a quarter turn and keep there ,give a couple of kicks without ignition , then one hard quick kick with ignition on....works for me ,once the bike runs the compression will get better and so will the starting . Regards Andrew

Re: NO Spark on R50/2

Posted: Sun Jun 06, 2021 7:38 am
by Daves79x
Are you positive you adjusted the valve clearance on the correct stroke? Your clearances will be quite wide if you didn't.

Dave

Re: NO Spark on R50/2

Posted: Sun Jun 06, 2021 5:18 pm
by bigdave
Thanks for all the suggestions.
The spark gap is set at 10mm.
Valves were just checked and I am sure correct.
Other things in the way for a few days, but will get back to it middle of the week.
Thanks all,
Dave

Re: NO Spark on R50/2

Posted: Sat Jun 19, 2021 1:09 pm
by bigdave
Got back to the R50 today with some success.
After multiple kicks it fired off and I could keep her running with the throttle. After 30 sec or so she was backfiring a little but then stopped and settled into an idle.
Took it out of the garage, suited up and took off for a maiden voyage. Everything worked; brakes, 4 gears etc. Only went a few miles up and down our street (we live in the country). The front end feels "heavy" even with damper loose but this is an Earles bike so am guessing that is how they feel (new bearings in the tripple tree).
Guess I now have to figure out how to easily start the bike, but at least I know it runs now.
Hope to be able to get to the vintage rally.
Dave