just picked up/ troubeshooting

[HdBndit]

What a great day that was for me. I'm happy to be a new CB owner. 1979 CB750 10th Anniversary Edition

Unfortunately, I can't get her to fire up...

So far I've got a new battery, fresh gas, cleaned float bowls and brass screws (didn't touch float needles which I don't know why -I'm going to get in there again for a cleaning) brand new sparks, caps/wires.  

All electrical seems to be in working order, lights/turns, horn. Starter motor works fine, it almost feels like it wants to kick over but just doesn't get there. I did see a flame or two come out the exhaust hole? I've noticed that it seems like only one carb has good suction , the others not so much.

As of now, I don't have the Kerker exhaust on yet ( need to pick up gaskets and collars) and there's no air filter(s) over carburetors. I've tried starting fluid down carbs and choke all the way up but still no luck. Oil level seems to be fine. No unusual sounds or negative noises when trying to start her up. I bought the wrong size compression tester (too big for spark hole) so I still need to check compression still. Tested all sparks, all seem to be getting enough spark. Fuel problem/ carbs?

Thoughts are welcome. Thanks for your time.

[bear69]

Well, there are lots of things to check.

How long has the bike been standing? Why was the air box\exhaust removed?

These are fickle engines to start without the airbox and filters and exhaust fitted. Not impossible but easier when fitted. You may have to go back and clean the carbs many times before they are fully clean. Have you checked the diaphragms for splits, leaks.

Has the timing been checked? These are all easily checked while you are waiting for the compression tester.

Looks like a nice bike BTW. Good luck.

[HdBndit]

The previous owner told me the bike was sitting in his garage for about a year. I'm not sure about before that but it's most likely been sitting for awhile. He said the air box was removed to get at the carbs and to replace the boots and exhaust was removed to replace gaskets/collars.

I did take a look the diaphragms and they look okay, no splits.

I haven't touch the timing yet, I need to get a timing gauge tool and find info on the markings for top dead center. (my manual is in the mail)

It's going to be a project but I think the bike has potential.
Thanks for viewing

[woodsrider250-2]

There is a vacuum saftey petcock on these in addition to the lever petcock on the tank we're all familiar with.  The vacuum one works OK once the carbs are filled up/etc as there will still be fuel in there, but when the carbs are dry it can be a PITA to get them filled up again.  Usually more starter time than a fully charged battery will turn the motor over.  You can remove the vacuum petcock, and just use the manual one on the tank.  I left mine on.  If you blow on the right vacuum line you can get the bowls to prime.