I have a weird one for you guys and I'm looking for some insight.
A buddy of mine has a 86-88 Ninja 600 (think its an 86). He just got it and it has been sitting for a year. It ran previously, but didn't when he picked it up. We started in on it last night and I found that a vacuum line that controls a little bladder that opens the fuel control/switch was kinked. We drained all the old gas, took apart the fuel switch to make sure it wasn’t clogged with old gas and crud (it wasn’t), put new gas in and made sure there was no kink in the fuel bladder vacuum line. We opened the choke all the way and cranked it over. Much to my surprise, it fired, but didn't start. Woohoo!! After some much cranking, it started and ran with the choke about 3/4 open. We let it heat up and tried to give it some gas via the throttle, and it almost died. We gave it some more time to run and eventually with some fineness we were able to rev it up via the throttle. Now here’s the kicker; After it was hot, it still would not start without the choke 3/4 on. It would also not start via opening the throttle.
No biggy, I figure, its been sitting a year, lets check out the carbs. We managed to get them off and open them up. Not too bad, only a tiny bit of crap in the bowls, and a tiny bit of old gas stuck to the needles and some of the venturies (sp?). We cleaned them out via compressed air and some clean gas and put the carbs back in. Same problem, it would only start with about 3/4 choke, and no gas (via throttle). This time it seemed to run a little smoother, but still would not start without a lot of fineness.
I'll re-list the symptoms for those of you that skimmed my long-winded post:
a) Will start with 3/4 choke, but no throttle.
b) Will not start via throttle.
c) Once started, you can take the choke off, but have to give it quite a bit of throttle to keep it running.
It will be getting new plugs, oil and filter. I don't think its a cause of the plugs as it seems that once it running, it does not seem to miss fire at all...
Any insight appreciated.