Trouble getting '85 CB700 to start after a year of sitting

[polar8]

I recently picked up a CB700 that the owner stopped using because it was leaking some fuel from the carbs, and he didn't want to pay the shop to do float valve work as they quoted. He did have it running even with the fuel leaking problem.

I drained the tank, put in new fuel, got the petcock flowing again, and it won't start. I checked the outer two spark plugs and they had spark (didn't want to take off the gas tank to check the other two) and I also drained the fuel from the bowls on the outer two carbs to see if that would change anything.

At first, nothing was happening, then, it started making a loud "putt" once every 10 or so seconds. Not sure if this was the engine firing or just relieving pressure created by the starter motor moving the pistons? Then it started putting regularly every second, I think that one cylinder was firing. It would putt softly with the throttle closed and a little bit louder with the throttle open.

I'm thinking of just taking off the carbs and cleaning them, which I was planning on doing anyway to fix the float valves. Anything I can try before I do that? Thanks!

[Munkey]

Sounds like the choke passages are clogged in the carbs. your bike doesn't have a butterfly type choke. It has enrichener valves that when opened, more fuel is pickup up through an extra pickup in the float bowls making the mixture richer. These pickups and the passages that the extra fuel flow through to get to the intake are pretty small and clog easily. Pull the carbs, give them a good cleaning and pay extra attention to the enrichener valve parts and passages.

[drdubb]

Listen to Munkey. If I had, it would have saved me a ton of work. Those passages in the bowl are tiny, I had to pull one strand of wire off a wire brush to clean them. Once you think they are clean, spray carb cleaner in them and see if it comes out of the enricher passages.

pulling carbs is a pita, but after a few times you get good at it.

[floridahawk]

[drdubb;  pulling carbs is a pita, but after a few times you get good at it.]
 Your right with that. Had to pull mine 3 times before I got them total good to go, after the PO let the bike sit for 2 1/2 yrs.  you'll be a pro when your finished.

[polar8]

What did you forget to do on the first and second times? Hoping I can get everything right in the first shot...

[Hondo]

And throw a new set of plugs at it while you're in there-

[biometrics]

And when the bike is put away for the season, make sure you put a good amount of seafoam in the tank --- and then run the engine long enough to make sure it gets to the carbs...

[MOPARJOE]

I would try a set of plugs right away, and see if it starts. It was just about to start, but the choke passages are most likely blocked. It "should" start anyway, as long as it's kinda warm out (and has fresh plugs). I had the same problem on a bike last summer, and it finally started, but never ran "right", even after full warm up. Once running, you can run a can of SeaFoam through it, and see if it clears up everything (it works sometimes); it's MUCH easier than pulling the carbs if you don't have to!!!

[polar8]

Thanks everyone for the suggestions. I pulled the carbs, and saw that all of the pilot jets were plugged. I cleaned the heck out of the carbs and boiled the bodies. Put everything back together and after a couple tries it roared to life! .... then promptly died. Then it wouldn't start up again. Eventually it backfired which prompted me to take out the carbs and clean them with a wire brush. Threw those back in and it started right up. At first it wouldn't idle without choke but I rode it around the block a couple times and it idles perfectly now.

Thanks again for the suggestions, everything helped!

[floridahawk]

  Well you asked the ? got the answer (of why it took three times)  These girls (bikes) have are hard time starting if they sit around and no one plays with them. Glad You got her running after only two.