Bubbling only happens after a successful turnover of the engine. So if the starter runs out of juice and the engine doesn't turn, no bubbles. It did catch for a second or two earlier, I don't think there is an issue with the engine for now.
Took some time to trace the bubbling to its source - it is definitely coming from the carbs bubbling fuel back into the airbox, that is where it is most audible (I took out the filter and you can clearly hear this happen anytime the starter turns over the engine.) Also yes, the oil did get contaminated - I drained the crankcase out completely and replaced with new oil. The old filter is still in there, but I am waiting to find the culprit of this bubbling before I swap in a new one. Will check sparks now too, I have a new set of those waiting in case they are also toast. Most sources I have checked seem to be of the opinion that it simply must be the floats. I am loathe to do this, but I will reopen the whole thing again and quadruple check. Also I am worried now about the flimsy nature of the diaphragm - I have never seen one new, but it seems to me they should be stiffer than they are. Of course replacing these is nearly impossible and expensive. Could an imperfect seal from the diaphragm (are they even meant to perfectly seal?) cause the bubbling noise? Back to the garage - please ping with thoughts as you have them! Thanks! On Apr 20, 2:19 pm, Dale <[email protected]> wrote: > do you have someone hiding in the oil pan??? is the bubbling/gurgling > maybe more of a grinding with the starter gears??? > > did you have gas in the oil??? if so then the flooding is compounded > by bad rings/cracked piston...maybe fluid locked the motor and cracked > something??? that could explain a bubbling....what do/did the spark > plugs look like? > > On Apr 20, 9:49 pm, Graham Rogers <[email protected]> wrote: > > > > > > > ... and you've got enough of us baffled by it that we want to know > > the outcome... > > > On Apr 20, 2010, at 11:11 AM, JP wrote: > > > > Hmm, yeah. Thanks for the ideas guys. Dale, I haven't tried leaving > > > the drains open - not a bad idea at all, if only to see what the heck > > > is happening. > > > > Vacuum hose seems dry, and no matter how much I shake or toss the tank > > > with the petcock set to "ON" it doesn't seem to leak a bit. Which is a > > > relief.. however, I'm going to take another look at the valve. Maybe > > > there isn't enough gas in it to cause the flooding, it's possible that > > > a really full tank caused so much pressure from gravity that it pushed > > > through anyway. > > > > Also - let the oil/gas drain from the crankcase for days, drained & > > > opened up carbs, cleaned everything up, reassembled & readded oil.. > > > turned over the engine without the fuel tank attached and I heard the > > > bubbling noise again!! That is very troubling! There should only be > > > oil in there at this point, and it shouldn't cause a gurgling noise.. > > > should it? Hmm.. > > > > Still determined to figure this out.. I bought this bike to learn how > > > to wrench.. and darn it i will fix this.. > > > > -- > > > You received this message because you are subscribed to the Google > > > Groups "Nighthawk Motorcycle Lovers!" group. > > > To post to this group, send email to > > > [email protected]. > > > To unsubscribe from this group, send email to nighthawk_lovers > > > [email protected]. > > > For more options, visit this group athttp://groups.google.com/ > > > group/nighthawk_lovers?hl=en. > > > -- > > You received this message because you are subscribed to the Google Groups > > "Nighthawk Motorcycle Lovers!" group. > > To post to this group, send email to [email protected]. > > To unsubscribe from this group, send email to > > [email protected]. > > For more options, visit this group > > athttp://groups.google.com/group/nighthawk_lovers?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "Nighthawk Motorcycle Lovers!" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group > athttp://groups.google.com/group/nighthawk_lovers?hl=en. -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en.
