CB360 running on left side only

addisonsan

New Member
Hey guys, did some searching but couldn't find a close enough answer.

Here's the deal:

Newly rebuilt top end on 1975 cb360, compression is fantastic on both sides (which i take to mean i did everything correctly). New plugs(old wires and coils), but i have confirmed spark on both sides (running a pamco electronic ignition and wiring is 100% correct). Just got my carbs back from crazyPJ and they are flawless.

However, I am only getting the left side to start, the right side wont run, just get some backfiring(?) or a puff of something out of the right air filter and the left sides gets going first kick. I've tried switching the wires around related to the pamco to test if its a bad sensor but its always the left side that runs and the right that doesn't. Additionally, it seems only starts when i've flopped the sparkplug wires (left on right and vie versa). Any ideas??
 

trek97

No Custom Title
DTT BOTM WINNER
addisonsan said:
Hey guys, did some searching but couldn't find a close enough answer.

Here's the deal:

Newly rebuilt top end on 1975 cb360, compression is fantastic on both sides (which i take to mean i did everything correctly). New plugs(old wires and coils), but i have confirmed spark on both sides (running a pamco electronic ignition and wiring is 100% correct). Just got my carbs back from crazyPJ and they are flawless.

However, I am only getting the left side to start, the right side wont run, just get some backfiring(?) or a puff of something out of the right air filter and the left sides gets going first kick. I've tried switching the wires around related to the pamco to test if its a bad sensor but its always the left side that runs and the right that doesn't. Additionally, it seems only starts when i've flopped the sparkplug wires (left on right and vie versa). Any ideas??

because its easiest try swapping plugs, or fresh one on right. right may be fouling. also, (if Im thinking correctly) the pamco has individually adjustable pickups?? check timing w a strobe light. double check carb sync w guages. crack open the right bowl drain and make sure the float isnt stuck closed. and then, even though you say shes got fantastic compression check intake valve gap.
 

Ellwood

Vintage person on vintage bikes...
Had this kind of thing on a cb350 newly rebuilt. Drove me crazy. Think it was a valve thing because I revved it up trying to get right cylinder to fire up and it backfired loud and the problem was gone. Ran like a top after that. Never figured it out. Best of luck... I'll keep trying to think of what it might have been.


Sent from my iPhone using Tapatalk
 

alzcbz

Been Around the Block
Make sure to have a good, fully charged, battery. May even try jumping from a, non-running car, battery.
 

sal paradise

New Member
It could be a number of things, but I would look at the plug. See if its getting gas.

On my bike, my right float level was too low.
 

DesmoBro

Busted Nut
Def make sure the carb has gas then check timing .....is the exhaust clogged up?....prob not that.....are the valves adjusted ?
 

crazypj

Split personality, I fake being smart
I would say check battery under load (just stick a voltmeter on it while running 12v or more = good)
Check both carbs are getting fuel, I've had a few sets where floats have gotten stuck after shipping (because Post Office takes so much care with packages ;) )

sal paradise said:
On my bike, my right float level was too low.

Too low will increase fuel level and make bike run rich.
I think, you mean too high?
Best setting for 360 carbs with K&N is 20~21mm instead of 18~19mm
 

addisonsan

New Member
Battery is good, floats are good, checked all valve clearances and they are good, messed with the timing in both directions to see if it would fire up on the right side but no dice. I'm going to replace the coils today ,there is spark on both sides but maybe its just too weak? As i mentioned they are original and i probably should have done this at the beginning but i tested them and they were ok. That was months ago though
 

Sonreir

Oregon
DTT SUPPORTER
Pull the plugs after running it (on one cylinder) for a minute or so. What do they look like?
 

addisonsan

New Member
Ok so new coils are in and now I get nothing on either side. nice strong spark, redid timing chain adjustment and valve adjustment, checked carbs again and nothing stuck or clogged. At my wits end here


Sent from my iPhone using DO THE TON
 

crazypj

Split personality, I fake being smart
If your not even getting a 'pop' you did something wrong fitting coils.
Remove points cover, remove plugs. Insert plug into plug caps, ground plugs, flick points open by hand (make sure points heel isn't on cam keeping them open)
Then check you have correct sides wired up.
When it's 'running' re-fit Pamco
 

teazer

Over 10,000 Posts
DTT BOTM WINNER
The original problem sounded like a combo of wiring on the wrong coils and timing.

Pull plugs to check them and while they are out, remove alternator cover and valve covers. Turn on ignition with plugs grounded and turn motor over and determine exactly when each side sparks in relation to cam timing and alternator position.

Each side should fire just after the inlet valve closes and before the engine gets to the T mark.
 

addisonsan

New Member
Years later! haha

Did some testing and found thhe pamco ignition was faulty. Switched it out for an electronic ignition from Charlie's place here in LA and it fired right up. Been running great ever since!
 

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