Another one with stalling problems

Wow, my first post in the big boys forum. Im so proud. I can see many people previously have asked this question but for the life of me I cant find any damned solutions that worked! So I figured id start my own thread and document what I've tried and what eventually ended up working.

The Bike:
VFR800, 2004 model, 80,000kms on the clock, completely unknown service history but seems to have been reasonably well looked after.

The problem:
Rolling up to an intersection, engine braking with the clutch out - sometimes when I try to get back on the power (if revs are below 3,000) it will just die. The bike hasn't completely died on me yet since I can usually feather the throttle for a second or two and it starts running again. Its as if the overrun fuel cut stays on (if they even have it on the VFR).

One time I pulled away on a roundabout/traffic circle and made it to the center lane before the engine started to die...which resulted in me scooting the bike along with my feet whilst fumbling with the clutch and throttle trying to get out of the way of a truck. After what felt like an hour but was probably barely 5 seconds, the engine roared back into life and I fucked off the closest exit in a wheelie doing my best to hang on. After that day, it went from being a minor inconvenience to something I really should fix.

I could be imagining it, but it seems to happen way more often when the fuel level gets below a quarter tank. I thought it might be fuel surge, but surely the tank is baffled well enough to handle that kinda thing.

What I've tried so far:
Not much. Took the fairings off, discovered an air filter full of crap and some mildly dirty oil. The plugs in the rear bank were Denso so I reckon are the factory originals. Have ordered some service items to throw at it and we'll see how it goes from there. Spark plugs were not cheap...my wallet hurts now.

I think my idle speed might be a smidgen low, usually sits about 1600cold and when hot it hunts between 1100-1200 in that lumpy way these bikes idle. Will re-set it once ive got all the new fluids and plugs in it.

Also I read somewhere that there is a common electrical issue with one of the charging system connectors....if someone could point me in the direction of a nice write up, that would be awesome. I don't like the idea of an electrical fire around a fuel tank im straddling, so would rather check it out now before I smell burning.

 

No tank baffles on Honda streetbikes. The plug to watch is between the stator (3 yellow wires) and the regulator, but occasionally the plug atop the starter relay goes bad too with melted, burned wires.



Probably best to increase idle speed a bit, but slightly dragging clutch plates could be the problem too, dragging down engine speed even when the clutch lever is pulled in.

 

Progress. Threw a set of plugs at it ($200NZD...ouch), old ones that came out were Denso and looked pretty well worn so i suspect havnt been changed or looked at since the 40,000km inspection. I know someone had been in there since they wrote RR/LR on the coil packs. Bumped the idle up to 1300 hot and its sounding much healthier now.

Plugs were a dark tan color on the insulator and the fuel economy is bang on what i should be expecting so everything is running well. Changed the oil and filter while i was in the giving mood and went for a ride.

Didnt get the bike to completely stall but it did mess around a few times. Its always engine braking into roundabouts then getting back on the power that causes the problem. One time, I put some light power on in 2nd to exit a roundabout and it had no pull at all. The engine note was light but steady, then it picked up on all 4 at the same time and ran great without moving the throttle. Its as if either the timing is all to piss or theres a fuel pressure problem.

Thoughts?

 

Spark timing is set within the CDI box and never goes off. If you have a tps, problem could be there.

 

Spark timing is set within the CDI box and never goes off. If you have a tps, problem could be there.