CB360 popping after "Tune Up"

Mac_2766

New Member
Hey guys,
I recently got my cb360 up and running after cleaning the carbs, putting in new gaskets, relining the tank, sticking in new in line filters and cleaning up a lot of the wiring. Bike was running pretty well, but being that this is my first cafe build/experience with an older bike I wanted to have a mechanic give it a tune up and sync the carbs for me as I didn't have the tools to do so myself. Took my bike to the Honda dealership to have the mechanic give it a once over to make sure I didn't have any outstanding problems. When i picked it up the next day he gave me a list of things that he had done. They were as follows: Carbs were totally out of whack as expected,so he synced those, Checked compression 165psi on both sides, checked valve clearance -good, adjusted points as one one slightly off and adjusted the timing with a static light (I think that's what it's called), spark was good, air filters were fair. I was pretty happy as things seemed to be in fairly good order, minus a battery that he said wasnt holding charge(only reading 12.6v), and not so great spark plug caps. At the bottom of the sheet though he had written that the "popping" in the right exhaust was "still there". The thing is there was no popping when i took the bike to him!! He said it could be caused by the battery not holding charge or bad spark plug caps being loose. I know its probably not a huge deal,but popping has been driving me nuts!! Figured i could just make some adjustments to the pilot screw to richen things up as he only had it at 1 turn where i was running it at 1.75, it helped some, but its still there. I was super pumped to finally get this bike up and running and now I'm just bitter that I took it to this guy. Any ideas what he may have done to cause this ??
Thanks!
 
Carb sync is probably still out as 360 uses different thread adapters to everyone else and Honda discontinued them around 20+ yrs ago
Are you running stock airboxes?
If not, you will have a problem.
Do the usual check for air leaks on intake and exhaust
Static timing is OK, but, he should have put a strobe on it to check advance
12.6 v will be OK but you need to check battery voltage @ 5,000rpm
 
Thanks for the reply crazypj.
I am running stock airboxs.
What is the easiest way to check for air leaks?
Ill check the voltage later today.
I also noticed on the work order that he had the bike listed as a cb350!
 
Use aerosol , WD40 or similar and spray around all the intake joints, idle will change if it's leaking
 
Just checked the battery voltage. Its down to 12.2 at idle but stays constant at 5000 rpm, only occasionally dropping to 11.9. Is there any truth to what he said about the battery or plug caps being a possible cause of the popping?
 
Yes.
Your battery should never drop below 12.6 and these bikes aren't happy with a crappy battery in my experience.
 
Alright thanks for the info guys. Also, wondering if I make adjustments to the idle speed screw will the carbs have to be re-synced??
 
Adjusting the fuel screws won't affect sync, the only thing it does is richen or lean idle mixture which can affect first 1/8 of throttle opening
 
hmmm took it to a professional ? makes me cringe. Do what ever PJ says to do.
 
Yeah this will be my first and last trip to the dealership. Think I actually got the popping situation sorted out. 2 turns out on the pilot screws and a fresh tank of gas seems to have cured itfor now!

Now I'm having another bit of a situation. When I start the bike up from cold, for about the first 1\2 km (Sorry I'm Canadian!) there seems to be very little power and torque in the engine, then all of a sudden i get a burst of speed and cruise right along for the rest of my trip. Could this be traced back to the poor battery charge? Or could there be another cause? Also here is a before and after pick of where I'm at in the process so far. Thanks for the help guys!
 

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Sounds like it runs on one until warm,you using choke properly?
They don't like full choke after starting, there is a detent at about 5 degrees
 
I actually don't use the choke at all.....For some reason the bike will only start with the choke off....
Can you explain to me what a detent is?
 
a bump that spring thing fits in
If it's starting without any choke it's too rich
 
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