So I have an issue with my CB750K staying running, and I could use some direction on where to look next.
The problem: The bike starts fine with the choke pushed in, but requires constant throttle to stay going. When I start the bike with the choke out, it initially stays running without throttle, but within 30 seconds (or sooner) it requires constant throttle to keep it alive. It feels like the longer that it runs with the throttle, the more throttle is required to keep the RPMs steady.
What I've tried:- Took off gas line on the carb, to check if fuel is flowing (it is)
- Took off gas line on petcock to see what the flow looks like (Seems fine, but I'm really not sure what the flow should look like)
- Tried cleaning the petcock with carb cleaner and canned air
- Checked the airbox/filter (it's clean, looks almost new)
- Took off that gas cap to see if it wasn't breathing (did not change anything)
- Made sure the fuel line is routed to the carbs going only downwards. I have like a 4 inch piece of tubing going directly to the carbs.
Thoughts: I
think it's a fuel issue. I'm pretty new to mechanics, but this is the idea I got from reading some forums. I'm not confident the petcock is providing enough fuel. My understanding is that from the petcock to the carb, it's only gravity pulling it through - so when I increase the throttle, it gets enough gas, but that shouldn't be making it draw gas any faster from the tank. I can't really take it apart to look for gunk or blockages since it's riveted. Does anyone have examples of proper flow from the petcock? Any other ideas?
