Is the bolt that holds the points cam on a stock R5 ignition supposed to be magnetic?
Not by design, but since it is made of carbon steel, and sits within a magnetic field, it will be magnetized somewhat. It does not really matter for the operation of the alternator or the ignition.
If it was made out of an austenitic stainless steel, like AISI316, it would not be magnetized.
But stainless fasteners are not always a good thing, since they have more tendency to gall/seize, have lower tensile strength than 8.8/ grade 8, and are also more prone to metal fatigue issues.
So stick to an OEM Yamaha bolt for your points cam and alternator rotor, that is my advice (And if it is the same as on the RD, it is not a regular hardware store item anyway)
That makes perfect sense; trying to eliminate any potential wrongness as I'm still having trouble.
I've tried everything suggested here and whatever I did to get the rusty R5 going a couple years ago with consistent results. Even swapped a carb from the running bike just to make sure. Runs great at idle and then for some revs on the stand and a quick blast or two, then back to one side, usually the left but not always.
I compared the Joker Machine brand points cam that came with the bike to a Yamaha one and they are not exactly the same profile. Swapped that out along with an RD ignition and am halfway done setting the timing which was accomplished much more quickly and with a more desirable contact breaker gap after the swap. I comically exploded a brittle plastic bottle of machine oil all over the ignition and into my face while oiling the cam felts, so ditched that unit.
Removed the harness and there is no voltage drop in the disconnected wires, eliminated ignition switch with and the voltage at the points lead is still down. Can coils that both show 4.6 and 13.6 be the problem?
Quote from: Greaser Greg on April 19, 2021, 09:41:11 AM
That makes perfect sense; trying to eliminate any potential wrongness as I'm still having trouble.
I've tried everything suggested here and whatever I did to get the rusty R5 going a couple years ago with consistent results. Even swapped a carb from the running bike just to make sure. Runs great at idle and then for some revs on the stand and a quick blast or two, then back to one side, usually the left but not always.
I compared the Joker Machine brand points cam that came with the bike to a Yamaha one and they are not exactly the same profile. Swapped that out along with an RD ignition and am halfway done setting the timing which was accomplished much more quickly and with a more desirable contact breaker gap after the swap. I comically exploded a brittle plastic bottle of machine oil all over the ignition and into my face while oiling the cam felts, so ditched that unit.
Removed the harness and there is no voltage drop in the disconnected wires, eliminated ignition switch with and the voltage at the points lead is still down. Can coils that both show 4.6 and 13.6 be the problem?
Coils that are bad can break down with heat. You'll ride fine for a bit then lose a cylinder or have a misfire etc. So, it's possible.
bad cylinder ignores four different coils including coil from running side.
swapped in a whole different ignition with same results.
getting down to bad (new) seal or bad ring to bore seal i guess. compression is at 120 and it ran great a few times. leak down test is next.
How come when I plug in a rick's regulator, voltage in the brown wires goes down, but still have battery voltage at orange and grey wires on ignition, huh? unplug and it goes up. this is with battery fully charged.
guy i bought the coils from on here says they ran his r5 no problem
yeah just order new coils from economy and consider it done.
the bolt is just an M7. they can be found .
last time both sides were on the right side was surging up and down at a steady throttle position. it's not the carbs, soo....
Quote from: Greaser Greg on April 19, 2021, 02:35:36 PM
last time both sides were on the right side was surging up and down at a steady throttle position. it's not the carbs, soo....
what do the plugs look like on the right side?
Did you check the wire from the negative side of the coil down to the points for the bad cylinder? You could do that by turning the key on, points closed, meter neg on points, meter pos on the coil neg wire (same wire, other end). There shouldn't be any voltage because you are on the same wire but if there is any voltage that wire has resistance and may get worse the longer you keep the key on and let it warm up.
Have you eliminated bad connections in the handlebar switch?
Quote from: 1976RD400C on April 19, 2021, 03:24:26 PM
Did you check the wire from the negative side of the coil down to the points for the bad cylinder? You could do that by turning the key on, points closed, meter neg on points, meter pos on the coil neg wire (same wire, other end). There shouldn't be any voltage because you are on the same wire but if there is any voltage that wire has resistance and may get worse the longer you keep the key on and let it warm up.
I'll try that just for kicks. Even with the colored wires and plug wires swapped, no dice on the same side almost every time. In other words, the left side works on either circuit. I also hooked up wires straight from battery to coils then straight to points with different condensers. I'm gonna try new coils since they read 4.6 ohms and I hear that's to high.
Quote from: Greaser Greg on April 19, 2021, 08:52:07 PM
Quote from: 1976RD400C on April 19, 2021, 03:24:26 PM
Did you check the wire from the negative side of the coil down to the points for the bad cylinder? You could do that by turning the key on, points closed, meter neg on points, meter pos on the coil neg wire (same wire, other end). There shouldn't be any voltage because you are on the same wire but if there is any voltage that wire has resistance and may get worse the longer you keep the key on and let it warm up.
I'll try that just for kicks. Even with the colored wires and plug wires swapped, no dice on the same side almost every time. In other words, the left side works on either circuit. I also hooked up wires straight from battery to coils then straight to points with different condensers. I'm gonna try new coils since they read 4.6 ohms and I hear that's to high.
Sounds like you have tested all the wires. Hope the coils fix it.
Checked for a worn Main bearing, like I suggested earlier?
Yes. They are all new. When I switched to OEM points cam I tried to move the end of the crank.