Loud noise when starting very hot Valk.

[PhredValk]

Hey. I was in downtown Toronto and got caught in rush hour traffic on Tuesday. The fans were whirring constantly and wouldn't you know it, the reserve LCD starts blinking? Stop and go, and no gas station in sight, so at one long red light I shut her down. Not really good for the engine, I know, but not good for me pushing the Valk in 80+ degree heat.

When I started her up there was a very loud 'CRACK' or 'SNAP' from under the engine. I thought it could be an electrical arc or something. It did it again when starting at the gas station that I finally got to as well.

Has anyone had this happen before? Maybe the fan system coming on in too much of a hurry? Everything seems normal on the fat girl since, and I can't see any burnt wiring or physical damage to the engine...
Fred.

[dalai-lama]

I have had it happen a few times over the last 10 years and it is something electrical.  It seems only to happen during high humidity and heat.  I have checked the relays, etc. and never found anything burned or even remarkable.  So I have no answer on what it is, but it has not hurt anything in 116K miles on my I/S.

the dalai

[doubletee]

Happens with mine whenever it's hot. I posted a similar question to the board last year or prior, and the consensus is that it's predetonation and nothing to be worried about. Like the previous poster said, it's happened repeatedly with mine with no observed ill effects.

[EDIT]

I searched out my post. Here's a link to it:

http://www.valkyrieforum.com/bbs/index.php/topic,7379.0.html

[PhredValk]

Thanks for the prompt replies. I have a 2500 mile ride home next week, and will spend much of it far far away from any kind of bike shop.
Fred.

[Patrick]

Predetonation , humm, thats interesting.. I'd like to know what that is.. There is pre-ignition and then there is detonation.. They are 2 completely different animals.. But,regardless, neither one of them will cause a noise during a starting attempt..

[doubletee]

Predetonation , humm, thats interesting.. I'd like to know what that is.. There is pre-ignition and then there is detonation.. They are 2 completely different animals.. But,regardless, neither one of them will cause a noise during a starting attempt..

Maybe a poor choice of words on my part, but I think anyone reading it probably understood the intention.

So, if you disagree with previous opinions on the possible cause, what are your thoughts on possible causes?

[Daniel Meyer]

My opinion is that with the hot engine and short shutdown time, the compression's still up, fuel is already there, there's hotspots in the cylinders, and it starts *instantly* instantly, not just the normal valk *instantly* if ya get my drift.

I think it's something in the starter/etc or some sort of detonation. (could even be detonation in the exhaust)

Common noise. I wouldn't sweat it.

[Ricky-D]

That's where the noise is coming from!  The exhaust and muffler.

I don't understand the need to shut the motor off in 80 degree weather.  That's what the fan is for.

And the tank has at a minimum a gallon of gas inside when the reserve tank level starts blinking.

These bikes are not that delicate and fussy and all that type treatment is not necessary.

***

[Patrick]

What would/could cause the ' crack or snap ' .. Don't know.. Never ran across the problem, I've not heard or experienced it so until I do I can't speculate on the cause..
My first thought was of a start of a fuel-lock,but, thats an unmistakable 'clank' .. And, his engine started.

[gordonv]

Same thing happened on my 99 IS. Posted ? here, and the consensis was that it is the starter relay triggering. I agree. A loud Pop/Snap coming from the RH side below you butt. Just were the relay is.

Normally wont be any problem. But for your piece of mind, take the connector off the relay and look it over before you get those nice burnt wires that RJ posts all the time, from when his burnt.

http://www.valkyrieforum.com/bbs/index.php/topic,14089.0.html

I don't know how to lock in the link, seems everytime I save it, it moves. I just used the word "starter relay" and found a thread with that as the subject line.

[doubletee]

Same thing happened on my 99 IS. Posted ? here, and the consensis was that it is the starter relay triggering. I agree. A loud Pop/Snap coming from the RH side below you butt. Just were the relay is.

Normally wont be any problem. But for your piece of mind, take the connector off the relay and look it over before you get those nice burnt wires that RJ posts all the time, from when his burnt.

http://www.valkyrieforum.com/bbs/index.php/topic,14089.0.html

I don't know how to lock in the link, seems everytime I save it, it moves. I just used the word "starter relay" and found a thread with that as the subject line.

The noise I'm hearing is coming from the Left hand side, below the butt. I closely inspected the starter relay when I first noticed the noise, since that's the first thing that sprang to my mind even though the sound didn't seem to originate there. It shows no signs of any problems.

I'm taking Daniel's advice and not worrying about it. It's been happening to me for over 10 years with no observed negative effects.

[Mr.BubblesVRCCDS0008]

Mine will do this sometimes after a short stop in hot weather. I chauked it up to pre-ignition knock. Bike starts instantly. Bike has 134k on it and it isn't a problem to me.

[gordonv]

I was referring more to PhredValk's original post. An intermitant problem when the bike is hot. Not some of the suggestions mabe by others, of what might be the problem. (not putting you all down, just trying to give PhredValk some help with his [not] problem).

[R J]

If it is the knock or pop I get every so often on MGM, it is unburnt gas in the muffler exploding when the 1st firing of a piston on start up.

Even if you desmog your bike you will get the bang/pop or what ever you want to call it.

MGM has done it since 1997 and 242K+ with no visible damage.

Even my John Deere lawn tractor does it occasionally, especially if i shut it off, well all I got to do is crawl off the seat and the SOB shuts down, just like when mowing, if you push on the reverse pedal, it shuts the mower blade down.

Someone run over their kid and sued John Deere and won, so now we all have to abide by the rules of no blade in reverse and not on tractor, it shuts off.  Ever have a dead battery and jump start it, and then have to yank cables loose while still setting in the seat.   Pain in the arse.    They have also made the wiring loom a jungle so trying to find out how to cripple the seat, you have to run though all the circuits, like brake pedal depressed, PTO off, and etc etc etc.  On the seat alone. We had to make 5 bypasses to keep it from shutting down when ya raise off the seat.     Haven't tracked down the Reverse one yet, but we are close.    Next time we have to sharpen the blades we will take care of that one.

The snow blower tractor, none of those safety switches work, they were simple to bypass, 1 bypass per system.

[PhredValk]

Thanx again, guys. I'm just going to leave it alone and ride.
Fred.

[CajunRider]

I've heard that sound several times, both on the Valk and on a BMW R1200C (the Beemer did it more often than the Valk). 

I'm not sure what it's called, (pre-detonation, ignition... etc. etc.) but to me it sounds like the fuel/air mixture in a cylinder on the compression stroke burns a little too quickly.  (Maybe it ignites a couple degrees before TDC???)  I could be wrong... I'm an electrical guru, NOT mechanical.

I get the same sound out of my dirt bike engine if I lug the engine down too low in the RPM range while using anything less than premium fuel.  That little engine does NOT like low RPM!!!

Neither the R1200C, the Valkyrie, nor the KLX450R has imploded on me, so I'd guess that it's nothing to worry about unless it's constant... once in a while won't hurt anything. 

[FryeVRCCDS0067]

Mine has made that sound under the same circumstances on and off as since I bought her in 2004. Seems to be pretty common and does sound like an "arc" sometimes. I don't sweat it anymore.

[HayHauler]

Mine has made that sound under the same circumstances on and off as since I bought her in 2004. Seems to be pretty common and does sound like an "arc" sometimes. I don't sweet it anymore.

I get this noise when shutting down for a short time after riding for a while (read warm engine).  It is an "arc" because I can smell the "electrical" burn smell.  Sometimes there is a pop along with the smell. 
Like others, I don't worry about it, I just tap the starter in these situations so it doesn't engage very long.  "I" think it is the engine starting, and spinning the starter after the starter has stopped spinning under electrical power.

P.S.  If I tap the starter button, I don't hear the pop or smell the electrical smell.  But I don't always remember.   

Just my $.02
Hay 
Jimmyt