Topic: Still not starting - but what is this all about?

[JerryRice]

I am still having a problem staring my 1974 CB350F.

I tool the advice of a member and sprayed carb cleaner
in the air filers. The bike started for a short time
and stalled.

I noticed that only the left two exhaust pies were hot-
the other two cold.

Seems gas is flowin to the carbs. Also, There is
spark on all four plugs.

This is crazy. The bike used to start no problem.
What is going on?

[Johnny5]

Something clogging the fuel system? Sounds like it's starving for fuel on the side that's staying cold.

[JP74]

how long has the bike been sitting?
how have you confirmed that fuel is getting to the carbs? 

[JerryRice]

Bike was sitting for 2 weeks.
I confirm the fuel is getting to the carbs by pulling th
fuel line off the carbs.. yup its wet.

Also I removed the carbs and cleaned them out.
Re-conected the tank and turned the petcock on.
I have a clear fuel filter. The gas wqas pouring
through for a long time..confirming that the float
bowls were filling up.

[JP74]

have you tried pulling the float bowls off and measuring the amount of fuel?
float height set to specs?

you are getting strong spark on all four plugs?

[WFO]

Bike was sitting for 2 weeks.
I confirm the fuel is getting to the carbs by pulling th
fuel line off the carbs.. yup its wet.

Also I removed the carbs and cleaned them out.
Re-conected the tank and turned the petcock on.
I have a clear fuel filter. The gas wqas pouring
through for a long time..confirming that the float
bowls were filling up.


.

Well this doesn't mean the float bowls were filling up on the two cold cylinders there is a drain screw on the bottom of the carb bowls loosen that and confirm the bowls do have gas in them also try to start and pull the plugs and see if they are wet confirming gas is getting into the cylinders (then go from there) check for spark on those two cylinders

[JerryRice]

The spark is not that strong across the board. However I am not sure what the normal output should look like.

I will check the float boals by unscrewing tonight - will report back
tomorrow thanks!

[Sporkfly]

Should have a bright blue spark.

Still sounds like a carb issue.

[JP74]

def sounds like a carb issue.    how in depth did you clean the carbs?

[CB750F2]

I suggest that if your float levels are ok and your plugs appear dry then check your low speed jets for clogging. Pat

[WFO]

The spark is not that strong across the board. However I am not sure what the normal output should look like.

I will check the float boals by unscrewing tonight - will report back
tomorrow thanks!

I had a spark plug showing spark on a ATV it wouldn't start it ended up being a bad spark plug try switching plugs from a firing cylinder.

[Hush]

+1 on the swapping the good plugs across to the cylinders not firing, also just a thing I do: drop a wee bit of gas into the cylinders that don't appear to be firing before you put plugs back in, if it fires with this form of backwoods fuel injection then yes you have proved its a carb problem.

[JerryRice]

Ok People. Thanks so much for backing me up with support trouble shooting this issue.
It seems to have been a loose kill switch connection. So far it starts. I may just
bypass the switch totally.

[Johnny5]

Be careful riding around without the killswitch.

Keep us updated on how the bike is doing.

[JerryRice]

Yeah, maybe I will just put on an aftermarket switch.