Hot bike wont turn over with start button?

[Badkarma]

Not sure if this has been talked about, but it happen to a few new RR's coming into the dealership I work for...

Here's the problem run your bike hot (abient temp +90F) on the streets coolent temp > 220F - turn your bike off....  then immediately turn on the bike on to the "ON" position (the fan should come on before you push start button) try to start it and you might notice the starter turns real slow or not @ all!

It would seem that the regulator rectifier (situated right behind the radiator and next to the headers on the left side of the bike) gets too hot...

[Crash716]

this has happened to me twice > and both times i had to jump start the bike.  It seems to happen when you get stuck in traffic and the bike is at idle for awhile.  i honestly think it is just that junky batteries that put in them.  after i jump started it and got the revs up i shut it off again and it started fine.

[Badkarma]

Well, according to my mechanic, the regulator rectifier is exceeding it's operating temperature while in idle and during stop and go hot temperature situations.  Honda has been notified, and he suspect they will come out with a retrofit heat shield or the thermostat is not not turning on the fan early enough....

I'm gussing you were able to restart the bike after it cool down a bit?

[Crash716]

the bike is back to normal when she cools down, but in san diego in the summer it might be happening all the time?  Bike is running pretty hot actually 210-225F in traffic and like 188-195F at highway or running the canyons.

[Badkarma]

there's also another possibility that when the fan is on full blast, the system is unable to deliver enough juice to the starter...  we haven't try to short the fan and then start the bike when it's cool...

[CBR 600RR_TN]

this sounds like a problem that older model chevy small block engines had becuase there starter got to hot(not a motorcyle but same problem).  A quick fix would be to get some ice or a rag soaked in cold water and place it on the over heated part.  It will cool it down quick and is much better than jump starting.  BTW don't jump start your bike off a car because its bad on the electrics.

[Badkarma]

huh?  hey this is a brand new bike, we shouldn't have to put cold rags on anything right?

Anyhow AHM asked us to fedex the regulator rectifier directly to the product specialist, and we'll see what happens, meanwhile, any bike that has this issue, gets a new regulator rectifier as replacement.

Having a regulator rectifier few inches from the header is just a bad idea...

[BlackOps]

there's also another possibility that when the fan is on full blast, the system is unable to deliver enough juice to the starter...  we haven't try to short the fan and then start the bike when it's cool...

The fan should not be sucking all of the battery power.

[Badkarma]

Agree, also if the rectifier stops working due to thermo shut down, then all accessories will drain the battery causing a weak start condition...

AHM R&D is actually flying up from LA to test ride with my customer to see how the bike is used.

I'll keep you guys posted

[hondatech]

The regulator/rectifier theory doesn't seem very plausible. If it drained the battery, it wouls stay drained. And it doesn't have a temp sensor, so it doesn't even know how hot it is. The fan thing sounds kinda fishy too, that isn't much load, I don't see how it would drain the starter. I'm going to go log on to Honda net and see if they mention anything about it. If I find anything out, I'll post it.

[BlackOps]

I talked to the techs at the dealer today and they said they have not seen any problems come in so far.

[hondatech]

I know none of ours ever came back. Maybe I'll take one this weekend and see if I can make it exibit the behavior. I did check the Honda dealer network thing, no mention was made, maybe it's too new of a problem.

[LuvMyRR]

This is starting to sound like a massive conspiracy cover-up  I only feel this way becaus I am having this problem as well.  Called American Honda Motor Co. and registered my complaint.  Thye said they would get back to me " Ya right!  I dare not drive with my high beam on. And every time I see slow traffic I'm think to myself "oH great"  THis blows!

[Badkarma]

Hondatech, All due respect, if you’ve taken any electrical engineering classes, EVERY modern power device has an operating range.  When the upper ranged is reached thermo shut down occurs to protect it self from damage, it does not need a separate temp sensor.  (You can ask all the VFR owners about their regulator/rectifier)  

If the regulator/rectifier was on the verge of thermo shut down its operation would naturally be very inefficient.  In that inefficient state the bike may start to drain more energy than replenished.  Further attempts to restart the bike with headlight on, fan - full blast combined with the regulator/rectifier in near thermo shut down may just exhibit the symptoms we’re discussing previously.  Naturally, when the bike is cooled, fan turned off, regulator/rectifier working correctly; there should be enough juice to get a few revolutions going on the alternator generating enough energy to get the bike started.

Reminder to all, anything posted here regarding this particular thread is of pure speculation.  Honda has not officially taken any position.
Concerning this customer few items are fact:
1. we were able to reproduce the problem in the shop easily.  Basically, no start when hot, starts when cooled.
2. Honda has asked us to fedex them the regulator/rectifier for inspection.
Sub note: on a very early crashed 600rr, a regulator/rectifier was ordered, we were subsequently call directly by AHM to find out why we need to order a regulator/rectifier.  Crash damage was the reason.
3.   Honda is coming to ride with the customer to see how the bike is used, requesting the customer to retrace exactly what was done.
4.   For now, a new regulator/rectifier and radiator temp sensor is to be replaced.
5.   This 600RR only has less than 50 miles on it.

[hondatech]

All due respect to you, but I don't need an electrical engineering course to teach me how a regulator rectifier works, but I think maybe you do. If the bike is not running, and you try to start it, and the starter cranks slow, it has nothing to do with the reg/rec. The regulator rectifier takes the high voltage AC the stator produces and converts it to a stable DC the battery can use to charge. If it isn't operating properly, the battery will either over charge, or not charge. Once the bike isn't running though, the reg/rec isn't being used. The bike starts off the battery. How hot the reg/rec is has nothing to do with it. In fact, you can remove it completely and your bike will still start and run fine. If running the bike drains the battery, and it needs to be charged to start back up, then it could be the reg/rec. If running it shuts it down and letting it cool starts it up, it can't really be the reg/rec. Wanna prove it? Go recreate the problem. As soon as the reg/rec heats up and the bike shuts down, pop a cold reg/rec off another bike on there and see if that makes it fire. I think you guys need to check battery voltage next time this bike shuts down, if you haven't already. If voltage is ok, you can eliminate the electrical system as a problem. Theres nothing on the bike that will charge the battery when it isn't running, right? So how does letting it sit cause it to start properly again? If your reg/rec theory was right, the battery would be draining no? How is it charging again by just sitting there? And I don't need to ask the VFR owners about their reg/rec. I've installed more than I care to remember. Not one did what the RR is doing.