points timing question

[m in sc]

yeah. who cares when it fires at 1 rpm?    I get it, i have 2 central tools sets myself and they get it really close, hell, i even have a dwell meter. however, light is the most accurate.

[Premiumjo]

Besides having to block open the opposite set of points to get the test light to go out on the side i'm trying to set
(having the same problem as Forexer and NEVER had this problem with this bike), it won't run on the right cylinder.

I had the same exact problem when I did my static timing on my 77RD.

Here's a video I found on youtube showing the issue 

https://www.youtube.com/watch?v=pq3bMRn2xyU

What I ended up doing was disconnecting both point leads and the condenser wires and then and only then could I get it to static time properly.

Good Luck!

I have very weak spark on the right side (new Iridium plugs). I swapped the orange and grey leads going to the coils and the right coil produced a strong spark and the left coil was weak  so I'm assuming i can eliminate the coil as the problem. The condenser is new and the points seem to be in great shape. The reason i was dicking around with it in the first place was because it ran on one cylinder one morning when i was going to ride to work. That night i pulled the plugs, checked for spark (ok) and took it for an 8 mile ride. It ran fine. Next time i tried to run it, it was back to one cylinder. So here I am. Electrical shit makes my brain hurt.
Any thoughts on my next step?

[quocle603]

I would replace your point or upgrade to a electronic ignition like VS dyna s. If you want to run the HPI or VaPe system that would be a good upgrade too, you can run batteryless

[forexer]

If both coils " checked good for resistance " per the service manual then I'd purchase some new points and a new condenser from Economy Cycle and then you'll be good to go - OR - break out the wallet and purchase an electronic ignition

[Greaser Greg]

"New" points can be shit right out of the box. NOS Yamaha fixed my R5 instantly. There's a thread on the forum about different part #'s for the actual contact breaker specified for other bikes that work fine; much cheaper.

[Premiumjo]

I actually bought new points, but the pivot pin is much smaller than the hole on the adjustment plate so i didn't install them. Guess i'll find some NOS ones.

[Plasticman]

I gave up on the OEM condenser and bought individual ones from Autozone.  This resolved my spark problem on multiple RD400s I've own.

Rob

[Premiumjo]

I swapped the points and I got a good spark on the right side. So now I have new points  and condenser installed, timing set at 2mm BTDC and new plugs. Spark still noticeably weak on right side. Started it and it runs like shit on the right cylinder. I noticed the right side points are arcing a lot ( not at all on the left). Do I have a grounding issue? I tested the coils and they both show the same resistance and really close to the specification. When I swapped the leads, the right coils produced a good spark so I think the coils are ok.
Killin me.

[quocle603]

If it is arching a lot, your condenser may be bad. Try swapping your condenser to see if the arching switches. If so, you can eliminate that issue by getting a new condenser from the auto parts store. They are like 5-8 dollars.

[m in sc]

^ yup.

[Czakky]

In my experience a working old condenser is better than a new questionable condenser....

[Premiumjo]

I tried flipping the condenser. Same thing. Then I switched it back the way it was and it ran on the right clyinder and the Left was arcing. Complete opposite of what I had. Not sure what's going on here. Maybe I'll take Czakky's advice and try throwing the old. condenser back on.

[m in sc]

strange.

I gave up on 40 year old ign electronics. coils, plug caps, wires, condensers, and points. all wear and have shelf life. even points.. the heels dry out.

[1976RD400C]

I would try measuring the voltage at the coils +.  With the points closed, putting a load on the circuit,  see if it is ok on each coil.

[quocle603]

That's very odd. Part of the reason why I went to electronic ignition, but I've had points work flawlessly on some of my bikes. We will get to the bottom of this.