71 CB350 Coil Trouble

[Theron]

I've been spending a couple of days trying to solve my bikes problem, and after reading many posts I thought I'd look for some feedback.

Naturally, the first post. Right?


I have a 1971 CB350. It was running well but rich, but then the spark plug wires starting acting up and falling part and finally bit the dust. I ordered some off ebay but they ended up being worse than the original.

So I went ahead and purchased some Dyna Single Output 5.0 Ohm Coils, wires and new plugs.

I installed everything, filled up and tank and now I cant get it to start. It does 'kinda' hit, and actually after a few kick starts and I turn the switch off sometimes it will pop.

The lower carb valve was overflowing, so I took it off and moved the float up.



(Image of bike pre-shorter cables)

What to try next?

[revcbl]

You may have tried this, but the only thing that occurs to me is to see if you're getting spark at all by pulling the plugs and laying them across the cylinder head while you kick it (having an assistant helps a bit). If you're not, then check your wiring again and make sure the plug wires have continuity. Upgrading the coils might require a different spark plug gap than the specs, but that shouldn't prevent it from starting.
Also, I'm not quite clear on what you mean by this:

It does 'kinda' hit, and actually after a few kick starts and I turn the switch off sometimes it will pop.

I like the long cable look, by the way-- cast a big "X" shadow from the headlight, like Batman or something.

[Theron]

When I was kick starting it, it felt like it almost wanted to start - and it was just getting too much fuel..

Because when I turned the switch to 'Off' (from 'Run) there was a strange sort of baby sized backfire - a small pop came from the mufflers.

[Johnj]

Try switching the right spark plug lead to the left spark plug and visa-versa.

[Theron]

Thanks for the replies

I got it up and running!



The left carb just constantly over flows gas now, if I ride around, then stop with the petcock still turned on gas just flows out of the overflow stem on the bottom of the carb.

Would the fix for that to take the bottom bowl of the carb off and bend the float up?

[Sev]

There are a couple of possible problems, but I'd start by checking to see if the drain screw is tight.

Then proceed by pulling off the float bowl and checking to see if the float jet/needle has anything on it, or anything that would keep it stuck open.

Then check the float height

Then check to see if the gasket is broken.

[Theron]

I got the overflow problem solved - I believe the float was just a bit too low.

The bike hates the 4-5k RPM range and struggles, I guess I'll have to rebuild the left carb again because at the muffler is not firing as strong.


Thanks again for the help