CB360 help... right side not firing

[eram]

Hey all,

I've checked all I can think of, but I can't get the right cylinder to fire. Left side is running great and plug looks a good color, but pulling the right could wire off that plug doesn't change idle, and pulling the plug it is NOT fouled...nor wet with gas.

Carbs: Tore carbs apart looking for blockage (were freshly cleaned) - all passages and jets clear. Air flows where it should. Also checked sync before i knew that only one aide was going - there is vacuum from the adapter hole. Idle screw is 1.25 turns from all the way in, and adjusting doesn't change anything.

Spark: yes. At least outside when grounding to cylinder head I get a nice blue spark. Each could gets equally hot and the sparks are there outside the head.

Fuel: I've been focusing on this...fuel lines show fuel is getting to carb...manifold is wet with fuel when I take carbs off, and there is fuel in the bowl. I checked float level and tore down carbs 4x with no change.

Valves: not stuck...at least not the intake. I didn't check exhaust side, but tappet moved great (and is freshly capped).

Compression: good, 160 each side.

Help? Please? I don't know what else to check!

PS. Last time I had it on the road, right cylinder did kick in around 7k+, but now no. -- leads me to main jet passage block, but air blows through to that opening outside the butterfly on the manifold side...and into the idle jet.

 

[eram]

Re: CB360 help... right side not firing

Oh, and sorry for formatting...posting from phone.

...and I should clarify that when I say valves are ok, that just means they're moving. Haven't pulled springs to see what shape they're in.

 

[frogman]

I noted my thoughts, Ideas...

Hey all,

I've checked all I can think of, but I can't get the right cylinder to fire. Left side is running great and plug looks a good color, but pulling the right could wire off that plug doesn't change idle, and pulling the plug it is NOT fouled...nor wet with gas.

Carbs: Tore carbs apart looking for blockage (were freshly cleaned) - all passages and jets clear. Air flows where it should. Also checked sync before i knew that only one aide was going - there is vacuum from the adapter hole. Idle screw is 1.25 turns from all the way in, and adjusting doesn't change anything. If you pull the air filters and squirt just a few drops in the throttle bore and then try to start it does it pop off a few times? If so then you still have a fuel issue.

Spark: yes. At least outside when grounding to cylinder head I get a nice blue spark. Each could gets equally hot and the sparks are there outside the head. Swap the plugs side to side see if the problem follows. It't not uncommon for a plug to LOOK like its working and have crack way up inside that causes it to ground out under compression.

Fuel: I've been focusing on this...fuel lines show fuel is getting to carb...manifold is wet with fuel when I take carbs off, and there is fuel in the bowl. I checked float level and tore down carbs 4x with no change. Make sure you have good flow an that your floats are set correctly. IF you pull the drain screw and turn on the fuel it should dribble out in a good stream. If not then you have a clog somewhere.

Valves: not stuck...at least not the intake. I didn't check exhaust side, but tappet moved great (and is freshly capped).
Compression: good, 160 each side. You have borderline compression, 165 is the COLD reading, at least you do get that much. 175 or Higher is where it should be if it is warm. You do have the throttle and the choke open during the test right?


Help? Please? I don't know what else to check!

PS. Last time I had it on the road, right cylinder did kick in around 7k+, but now no. -- leads me to main jet passage block, but air blows through to that opening outside the butterfly on the manifold side...and into the idle jet.

I would suspect that you have the floats set too low and or you have a clog in one of the jets. The brass jet that sits just ahead of the needle jet in the carb can be pushed out. I found all sorta nastyness under mine when I removed it. IF not then get to checking the ignition system, plugs are cheap. Inspect the coils and the coil wires for cracks and such, make sure all the barrel connects on top the engine are clean and tight.

 

[eram]

Re: CB360 help... right side not firing

Thanks for the reply!

The coils are new as of last August, as are the plug wires and boots.

I just sprayed starting fluid in the intake and no go.

Float was actuality set too high before I rechecked, and now its at 18-19mm...same as the left side that does fire.

I'm thinking now no spark in the chamber, so picking up another set of plugs on the way home today.

Anything else I can check/do? Going to tear the carbs down again tonight and soak all passages readily with fresh carb cleaner too.

 

[Molerat]

I had a similar problem it turned out to be bad points.

 

[eram]

Re: CB360 help... right side not firing

Hmm...I just put brand new points on last week...the right one does spark visibly though so I'll change them again maybe?

 

[frogman]

Make sure to follow the manual when setting the points the RIGHT side is the PISSY side so ask questions if you need to. There are 2 steps to setting the points one for each side.

 

[eram]

Re: CB360 help... right side not firing

Ya, I gapped both sides, then rotated the plate to set the left, and then I adjusted the right by angling that point -- that sound right?

Just went and rechecked l, and static timing is still on - and set on the compression stroke too. I dont have a light with me (have to borrow one) but static should be fine to get it to at least fire, no?

Update: didn't get a chance to pick up new plugs bc got home late, but I'm going to go swap plugs and see of the left starts with the suspect right plug...

 

[crazypj]

You did change the condensor's when you changed points?
I had an old Rover P6 once that would only run properly at 90+mph, faulty condensor 8)

 

[eram]

Re: CB360 help... right side not firing

I did throw on a new xs650 condensor when I changes the coils...will definitely check that! I'm running xs650 coils, but is the condensor incompatible?

Turns out its too late to try to fire it up...neighbors would exile me. But I swapped plugs, just reshot carbs and jets with cleaner, and rechecked floats and timing. Also shot up the cylinder with starting fluid before I put carbs back on. The manifold and plug was wet I noticed this time (could have been remnant starting fluid); so next up is condensor

Thanks everyone for these great ideas! I'll keep updating as I try them please keep ideas coming; you're restoring my sanity ^_^

 

[frogman]

You have to be partially insane to like these bikes let alone work on one.

 

[TFWG]

CB360 help... right side not firing

I had the same problem with my CL350. Ended up being the new plugs I bought. I put in the old plugs and it started firing on both cylinders. Leads me to believe it could have been the new plugs weren't gapped correctly out of the factory.

 

[eram]

Re: CB360 help... right side not firing

Ok.. so I checked the plug gap. Its ok. (I gapped them when I changed them last fall).

I switched the plug sides so to check if it was a sparking under compression / cracked plug issue - left still runs right does not

I swapped out the condensor; issue persists

I swapped coils, and there is no change.

This leads me to think points issue or combustion chamber issue? I did this before which led me to fuel problem, but the manifold and plug are wet, and the carbs are filling (good stream out of bowl...equal volume bilaterally).

New points, rechecked gap and timing...what combustion chamber / head issue could do this?

Going to go recheck compression here on a bit in case I blew something out and didn't realize xD

 

[teazer]

Two crazy ideas come to mind. One . remove the right plug and stick it in the ht lead and rest it on the head and kick it over. Does it fire with a nice blue spark. or let if fire up on the left side and check that plug for sparks as it runs.

If it the plugs has a nice blue spark it's probably carburation. How are the diaphragms? Do teh slides lift evenly and drop smoothly on both sides?

When you cleaned the carbs did you remove the jets and adjusting screws and blow through every passageway/drilling and compare left carb to right for each drilling/jet? I use a can of carb cleaner to blow through one drilling and then repeat on the other carb to compare flow. Then I move to the next drilling and compare both and so on.

Are you getting flow out of the bleed holes at the butterfly valve?

 

[frogman]

OH yeah one for sillies sake, take the points cover off and see if it runs the right side will ground in the cover if it is bent or twisted too far to the bottom.

IF so then the tab that holds the wire headed to the coils is where it grounds, either bend it back or put a few more gaskets on.

 

[eram]

Re: CB360 help... right side not firing

Yep, I did both of your spark tests - good blue spark even when running.

I thought carburation too except the manifold is wet when I remove the carbs?

I've removed all jets and holders, blew cleaner through with the little pipe nozzle thing. Then I blew air through and seems same to me both sides? Did this for all passages I could find - pilot, main, main-to-pilot, secondary main, all 3 air, from the air/fuel screw hole, the place where the fuel line hooks on, and the outlet of that under the float. If the bleeder hole youre referring to is the small hole on the manifold side of the butterfly on the bottom of the carb bore, then ya. I shot cleaner and tried air through (limitation of angle and nozzle) and definitely got flow. I did of through both trhrough the air/fuel screw hole and back from that hole.

Diaphragms are not ripped and I even checked for pinholes. Eavh slide smoothly although the right seems to have just a hair more resistance... perhaps something that would throw it out of sync but not stopping it from running I don't think?

Just rechecked compression - 150 both sides. Lower than when I first checked two weeks ago? But still even and runnable...

Gotta take a break from it to do some work, but still going crazy :x

I'm probably just missing something small and dumb that I overlooked and didn't think to mention. ><

 

[eram]

Re: CB360 help... right side not firing

Difference in compression explained: first time was without pods on...this time kept them on.

If it matters, I'm running k&n pods with a relatively free flowing stock-length 2-1 exhaust. Carbs have been rejetted on secondary main to 112. Not sure if this info would matter though since left is running fine?

 

[eram]

[quote author=crazypj]ground capacitors or they won't work.
You should have one for each coil, the XS650 is double pole so one wire goes to each coil and grounds through body[/quote]

just putting this here so I remember to double check my ignition grounds when I get home from work - t'was PJ's insight on someone else's problem

 

[jmemmert]

Check your valve clearance. I had a 660 rhino that had everything good. Compression, spark, fuel, air. I was baffled. I decided to check the valve adjustment. Fired right up after an adjustment. It was a hair tight on the exhaust side. Causing them to open too early resulting in no fire. You say you have compression, but do you have compression at the right time? Just a thought...

 

[eram]

Just wanted to update - I never figured it out. I added an extra ground wire to the condensor which helped a little...enough to get it to fire on occasion, but it was never right. This leads me to think it was a bunch of issues...one of which being valve adjustment, because out and about seeing if I had fixed it one time, I heard a loud clack and then a lot of valve noise. When I got back to the garage, I couldn't get one of the tappet covers off.

Long story short, I've given up on this engine as the cylinders got back from being bored and honed in the engine that matches the frame Thanks so much for all the feedback everyone!

Aaaaand off to start a new thread on the issues going on there XD