RC51 Forums banner

1 - 20 of 39 Posts

·
Registered
Joined
·
311 Posts
Discussion Starter #1
I don't know if it's a stall or not, but I'll shift down through the gears as I come to a stop and the bike just dies on me. I recently changed my spark plugs and air filters. I don't know if the issue is related, but I checked all the plumbing and everything seems to be connected fine. The bike no longer has the PAIR system in place. After the bike has shut off I'll restart it and the FI light stays on. Another thing I've noticed is that my exhaust sounds like rice krispies as I'm off-throttle in gear (crackles and pops). Today I lifted the gas tank to see what's what and noticed what seems to be some fuel in my airbox, nothing major, just some residue. Otherwise the bike feels great, it really needed some new plugs and the improvement is vast to say the least outside of this stalling issue.

I've also checked the wiring, but nothing in the electrical has been changed since I bought the bike and I've never had this issue before. Any help would be great.
 

·
Super Moderator
Joined
·
6,485 Posts
What's your idle speed?
Popping on deceleration usually indicates a lean condition.
Usually it's due to the PAIR system, but yours is removed.
Are you running an aftermarket exhaust system without a power commander?

Some residue is common in the airbox.
The crankcase vents to the airbox via the crankcase vent catch tank.
Any additional residue drains down the crankcase vent tank hose, which needs to be checked and drained periodically (about every oil change).

Have you shorted your green service connector and switched the key on to see what codes are being reported?

Remember the ECU stores any codes it finds, so it might be better to clear the previous stored codes to prevent confusion with any new ones generated.
The procedure and codes are in the service manual.
 

·
Registered
Joined
·
311 Posts
Discussion Starter #3
My idle sits at 1000-1100, except when it stalls, of course. It only starts to pop once the FI light turns on. I have a power commander II w/ akrapovic full, but it's been on the same map and I never touched either. The only things I touched were my spark plugs, rear spark plug wire because the boot had torn and I re-oiled my K&N filters, which were filthy and had been in the bike since I bought it.

I cleaned my filters tonight and it seems to have helped with the idle fluctuation, but it still died on me a couple times. The way I re-created it was to rev-match downshift and blip it in first then hold in the clutch as I rolled to a stop.
 

·
Super Moderator
Joined
·
6,485 Posts
Your idle is a bit too low.
It should be at 1300 +/- 100 RPM.
It's possible that alone may be behind the stalling.

I used to have an '05 'Busa that the idle screw would slowly back off due to vibration.
It too, would tend to die in the situation you described.
Once I adjusted the idle RPM back to spec, the problem stopped.
 

·
Registered
Joined
·
311 Posts
Discussion Starter #6
I think I'm getting a 1 code. My engine died today and I did the check engine procedure and the FI light just blinks once then after 4-5 seconds blinks once again and repeat.

What is the MAP sensor and how can I fix it? I'll try to just mess with the idle and see if it happens again, but if the MAP sensor is anything like a MAF sensor in a car, wouldn't it make it run sloppy while running as well?
 

·
Premium Member
Joined
·
8,335 Posts
MAP sensor malfunction will make the bike run like crap or not at all. Have you done recent maintenanve, maybe as easy as a loose coonector. Makes sense with the issues you are describing.

p://www.rc51.info/index.php?page=service is the service manual link.
 

·
Registered
Joined
·
311 Posts
Discussion Starter #8
Yeah, I'm off tomorrow so I'll take a voltage meter to all the things the service manual tells me to do. I checked all the wires I could have touched while under the tank, but maybe I missed something.
 

·
Registered
Joined
·
136 Posts
I have my idle set at 1400rpm.A low idle might sound cool but its not doing your engine any good because of low oil pressure! (harley owners like to have a just ticking over idle but little do they know the damage its doing)
 

·
Super Moderator
Joined
·
6,485 Posts
I have my idle set at 1400rpm.A low idle might sound cool but its not doing your engine any good because of low oil pressure! (harley owners like to have a just ticking over idle but little do they know the damage its doing)
Air-cooled H-D engines use roller bearing crank and rod bearings.
They don't need near the oil pressure that plain-bearing engines do.
More film strength than pressure.
 

·
Registered
Joined
·
311 Posts
Discussion Starter #13
New development: My bike is starting to die on me while on the highway. I noticed the issue is that the bike starts losing power and throttle response dies. I turned it off then on and it started up again, but the issue is remaining.
 

·
Registered
Joined
·
136 Posts
Thats an adjustment screw so no. Pull the small vacum (the one without a clip holding it on) hose off the fuel pressure regulator (the round thing )in the picture, if fuel comes out its faulty.(prime the pump but dont start the bike)
 

·
Super Moderator
Joined
·
6,485 Posts
That's the rear throttle stop screw.
It's pre-set at the factory when they set the vacuum balance between the two cylinders.
Notice the capped vacuum line just to the left of the set screw.
Generally, don't mess with them unless the two throttles are out of balance.


There's also one for the front throttle.
 

·
Registered
Joined
·
311 Posts
Discussion Starter #18
FPR seems good, took the hose off and primed the fuel pump. Just checked my codes and now I'm throwing codes 1 and 9. I never touched anything to do with hte MAP sensor while doing my plugs/wires/air filters so I don't believe that could be it. The IAT sensor is the plug on top of the airbox, right?
 
1 - 20 of 39 Posts
Top