Left cylinder STILL fouling

m in sc · May 10, 2026, 12:56:39 PM

the oil flow is controlled at the pump check valve, so if you swapped them then that eliminates the oiling system

axldk6 · May 15, 2026, 11:43:33 AM

just ran across this. I have a similar (I think) problem on my left side. after many miles of tuning/adjusting my carbs I even went back to verify timing and points gap. put in a set of iridium's and the bike was running pretty good albeit needed some fine tuning in the mid range. bike sat for 2 weeks as I went out of state, got home fired it up and went for a ride.The left side started popping at higher rpm,came home pulled plugs and the right looked good , left looked wet and fouled . swapped plugs over and did the same again, it did clean up the left plug i put in the right cly. tho, seems to only really miss when in the higher rpm's? I run pre mix, have the SV coil upgrade . and this bike passed a leak down check when I bought it 2 summers ago, compression was good too. Hope you RDDAVE stumble upon the fix for yours, it might help mine.I am about over this bike , seems I fix one thing only to find another

axldk6 · May 15, 2026, 11:51:07 AM

fyi, I have only put about 260 miles on bike since I bought it 2 summers ago (and it had no spark when I got it home). mostly tuning carbs. When bought: new condenser, new points, coil upgrade, leak down test: good, compression check: good, new battery, new mikes reg/ rec.

axldk6 · May 18, 2026, 08:45:46 AM

gonna answer my own question? after some trouble shooting,( rechecked timing, points gap) i found my charging system not working, it was working fine 2 weeks ago tho. actually it was draining down the battery ( a fairly new alarm battery, and a fairly new Ricks reg/rec ) and when it hit about below 9 vdc and I turn the light on the bike shut off. last time I checked the brushes and cleaned the ring all checked out . now I am wondering if the reg/rec is faulty? Any way to check it other than replace it

1976RD400C · May 18, 2026, 10:32:53 AM

You could start by charging the battery, then turn the key on and check the voltage going to the brushes. It should be about 10 volts. You also should be able to feel the magnetism of the rotor being energized using a small light screwdriver and holding it near the rotor bolt, as you turn the key on and off.

axldk6 · May 19, 2026, 07:58:56 AM

while retiming the bike the rotor was magnetized, I charged the battery and it held 12.5 vdc . I did the drain test with a 12 vdc blinker bulb and it did not drain it down that much( maybe .05 volt?) . guess I have to start back like I did after I bought it and ( found the regulator/ rec bad. replaced with a Ricks and was charging fine) and recheck the brushes / wire to wire on the alt. etc. Damn thing giving me fits!

m in sc · May 19, 2026, 08:59:56 AM

whats the battery voltage when running. ?

axldk6 · May 20, 2026, 09:24:37 AM

it was dropping the voltage as it was running. even reving it .

axldk6 · May 20, 2026, 01:11:15 PM

Quote from: 1976RD400C on May 18, 2026, 10:32:53 AMYou could start by charging the battery, then turn the key on and check the voltage going to the brushes. It should be about 10 volts. You also should be able to feel the magnetism of the rotor being energized using a small light screwdriver and holding it near the rotor bolt, as you turn the key on and off.

well, no voltage at the brushes. and the rotor bolt is not magnetize now.battery charge up too.

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Left cylinder STILL fouling