71 CB350 Hard to start dies at stoplights

[CB350]

My bike is back to being hard to start and sometimes stalling at stoplights. The carbs were rebuilt, the points set, timing set and valves checked by Greg at OhioCafeRacers.com. The bike routinely takes more than 5 kicks to start and then runs for a few seconds and dies. When it finally stays running it does ok, until I get it out on the street. Then it is still prone to die at stoplights for no apparent reason.

I'm going to increase the idle speed as a first step. Are there any other suggestions?

Gerard

 

[pyro139]

check carbs fuel shut off valve, i had same problem for 3 years and valve is what prop it was, now bike fires on half crank even cold.

 

[ProTeal55]

Sounds like a clogged petcock to me..

 

[CB350]

There is a small leak from the petcock that I am waiting on a new rubber seal to fix it. I didn't think such a small leak could be an issue.

 

[CB350]

One more question on the gas/carb issue. What is the standard diameter for the line running from the petcock to the carb? I changed it out when I got the bike and don't remember what the original size was - I do know what I ended up with seemed awful small.

 

[CanadaDan]

One more question on the gas/carb issue. What is the standard diameter for the line running from the petcock to the carb? I changed it out when I got the bike and don't remember what the original size was - I do know what I ended up with seemed awful small.

If it's running between lights then it's getting enough gas... you couldn't have forced too small a line onto the fittings anyway.

I had the same problems with the airhead... put in a new condenser and got a lot better. Replaced the coils & points and it now starts in a quick push of the starter. Of course I replaced the spark plugs and wires as well.

Once the starting issue is corrected then you can set the idle and balance the carbs and that should take care of the stalling... you may have two separate problems here... but you can't do anything until it starts properly.

Also double check the mixture setting, reset to the factory specs for initial settings. I've worked on more than a few bikes where the mixture was ridiculas... not to mention timing that was done by a mechanic... but way off.

Your plugs are going to be fouled at this point. Get a couple of extra sets. I also use some fine sandpaper to clean the plugs during tuning when they foul up... save a few bucks. Once running I put in a fresh set.

 

[CB350]

Greg from Ohiocaferacers redid the carbs, set the timing etc, etc when he had the bike not that long ago. He is pretty well known in the CB350 community for being a good person to go to for this stuff.

I might be overstating the problem some. The bike doesn't die at every stop light or even most of them, just some of the time and when the bike is first started up it always does that first time it comes to a stop. Then it takes three or four kicks to get it going again. Which is what it takes to get it started. It will always die the first three or four times it starts. To be honest, I'm getting fed up with all the little problems and just want a bike I can fix a problem once and be done with it.

It's my own fault since I knew what I was getting into with an older bike that hadn't been run for a couple of years.

As a physical rehab project this hasn't been the best choice - but I will do my best to stick with it.