Carb Syncing and Jetting
Posted by
mluk1 on
May 25, 2011; 5:02pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/Carb-Syncing-and-Jetting-tp2985119.html
I have a 1977 Cb750F2 and it's gone through some heavy mods but nothing really with the fuel system. I am running the stock exhaust but I have a custom Airbox. I am 99% sure that I have set the timing correctly but my bike has had problems starting. I am running kick start only and sometimes I will kick it and I can hear the engine pop or the kick start itself will kick back at me or stop half way down.
I adjusted the valve according to the specs in the Manual, I set my cam tension and couldn't get it right so I ran the bike and loosened the bolt and tightened it back up that way, then I used a timing light to set the timing for my plugs.
I had everything set up to sync the carbs, the gauges are reading and what not but when I turn 3 of the 4 air screws and blip the throttle there is no change in the position of the needle on the gauge. I turned the screws all the way in and out and they all still read the same. Except carb 1. So I took off the air screws and checked them all. The one that was working you could hear the spring crack as I turned it, the second one sort of and the three and four there was nothing. Is this because I am missing O rings underneath the springs? Is this why I can't sync my carbs?
So my question is, how to I get a proper reading on my Carb Sync Gauge?
Oh and attached is a picture of the airbox I am running, does it justify me changing the main jet? I think the ones in there currently are 108? And the filter in there is a lawn mower filter. And my Spark plugs were carbon fouled and I think one was fuel fouled??