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VFR800fi cutting out get very hot


Deepee

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Hi

tonight I was riding home, quite slow and the bike just cut out.  I noticed the temp was reading about 95 deg which is not unusual for VFR's.  I also noted that the frame was red hot, 1 second max to keep my finger on it. 

 

It would not start at all and the engine was just spinning.  I let it cool till the temp read about 80 deg and it stated but after idle for about 1 minute it cut out, temp was rising.

 

I left it about 15 mins and until it get to 75 deg and managed to ride the 1 mile home, temp hit about 86 deg then cut again.  I tried it a few more times and it did the same at about the same temp.

 

The oil level is good as is the radiator levels.  I am at a loss really, I did replace the starter about a week ago so have moved electrics about but it has run fine for the last week and I have done plenty of miles.

 

I am wondering if it is possible the radiator fan is shorting something when it comes on as I can only assume it is cutting about the time the fan comes on although I have not checked or confirmed if it is coming on or not.

 

The regulator / rectifier is not hot so I do not suspect this.  Voltage is at about 14.4v when running and is the same at the time it cuts.

 

I am hoping someone will have some suggestions. 

 

Thanks.

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When it's hot did you hear the fuel pump prime? I've seen fuel pumps stop working in higher temps as they begin to fail.

 

Might as well check the wiring for any shorts as mentioned as a precaution.

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The fan circuit is always "live" through the fan motor, the thermoswitch on the radiator just completes a ground path when above approx 100C. I think any short in that circuit would be more likely to take out a fuse than to stop the bike running. Easy enough to disconnect the 2P connector on the fan wire circuit and see if the problem reoccurs.

 

I don't suppose your problem is related just to the battery? In my experience these are more likely to fail when they are hot and the internal parts expand into unwanted contact.

 

Thtanner's suggestion about a failing pump is also a good one. 

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Coolant

If you see *continuous* temps higher than 220ºF (104ºC) below 180ºF (85ºC) then
trouble shooting is in order:

 

Continuous engine temps above 220ºF or 104ºC is also a problem and the proper
order of items to trouble shoot are:

1)Faulty radiator cap... system should hold 1.1 pressure ratio...
2)Insufficient coolant...
3)Passages blocked in the radiator, hose or water jacket...
4)Air in the system...
5)Thermostat stuck closed...
6)Faulty temp meter or thermo sensor...
7)Faulty fan...
8)Faulty fan switch...

 

Engine temps below 180ºF or 82ºC is an problem... it means that the
moisture produced during combustion is not getting hot enough to
evaporate out the pipe as steam... instead that moisture will migrate
to the oil and produce a milky white contamination...

Note normal by products of combustion is water... . Every gallon of gas
creates roughly 8 pounds of water vapor... we all have witnessed water
escaping out of tail pipes on cold mornings...

 

The sequence of events to trouble shoot are:

1)Faulty temp meter...
2)Thermostat stuck open...
3)Faulty fan switch... (stuck on)

 

Battery

Motorcycle troubleshooting is a form of problem solving... It is a
logical search for the source of a problem so that it can be solved...
it ain't about jumping to 10 conclusions at once... always eliminate
the battery first... because you find that 90% of the time it proves
to be the weakest link of your bike... and so much depends on correct
voltage that it's pays to have your battery tended to a charger at all
times...

 

To determine the condition of an Maintenance Free battery give it a
refreshing charge... wait 30 minutes... measure terminal voltage...

12.8 or higher is a good battery...
12.0 to 12.8 is a insufficient charge... recharge...
12.0 or lower... battery unserviceable...

 

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5 hours ago, Deepee said:

What do you think about the frame being so hot?

 

The frame is attached to the motor, which is hot. At least, to me it's always warm.

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I have done some testing and discovered that there is no voltage getting to the fuel pump when the ignition is switched on.

I checked the fuse box by the battery and all are okay, I am not sure what is 'upstream' of the fuel pump electrical connectors to test or even where the wires go as they go into the loom.  I am guessing and hoping it is a connector block that needs re-seating.

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I found the fault, it was a bad connection to a relay right next to the battery.  I snipped it out and re-crimped a new spade connector and it fired up fine.  Thanks for all the input.

vfr-20170926_134120.jpg

vfr-20170926_134134.jpg

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Terry, where did you get that diagram?  The US-spec bikes (that is for the '98-'99) are slightly different from Deepee's (presumably) UK-spec bike, but it's a very nice hi-res wiring diagram nonetheless!

 

Ciao,

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5 hours ago, JZH said:

Terry, where did you get that diagram?  The US-spec bikes (that is for the '98-'99) are slightly different from Deepee's (presumably) UK-spec bike, but it's a very nice hi-res wiring diagram nonetheless!

 

Ciao,

I don't exactly recall where this came from, probably something the Mr Google turned up for me. I keep my eye out for such things and have found them online for each of my bikes. So much easier to make sense of the diagram when it is nicely coloured like this. 

 

AFAIK the most common differences electrical between US and ROW bikes are the position lights in the indicators, or any solenoids for charcoal canister purge or PAIR systems specifically installed to meet tighter emissions regs. Those generally won't affect the more common wiring layout however. 

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On ‎27‎/‎09‎/‎2017 at 5:54 AM, Deepee said:

I found the fault, it was a bad connection to a relay right next to the battery.  I snipped it out and re-crimped a new spade connector and it fired up fine.  Thanks for all the input.

vfr-20170926_134120.jpg

vfr-20170926_134134.jpg

According to the wire diagram wire colour codes, appears the above plug is for the Engine Stop Relay. The Black/Pink wire not making connection will definitely Kill your bike instantly. Good Find. 

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On 9/27/2017 at 8:44 PM, Terry said:

I don't exactly recall where this came from, probably something the Mr Google turned up for me. I keep my eye out for such things and have found them online for each of my bikes. So much easier to make sense of the diagram when it is nicely coloured like this. 

 

AFAIK the most common differences electrical between US and ROW bikes are the position lights in the indicators, or any solenoids for charcoal canister purge or PAIR systems specifically installed to meet tighter emissions regs. Those generally won't affect the more common wiring layout however. 

 

Yes, the difference between US-spec and ROW-spec (okay, excluding Oz) bikes, at least until 2003(?) or so, was not only the position lights in the indicators but also the other circuitry differences to effect that.  At some point Honda voluntarily stopped fitting headlight switches--maybe it was earlier, in the late 1990s?  Anyway, even the starter switch is different because on the US/Oz bikes it kills the always-on headlights to allow more of the battery's power to go to the starter.  (On a ROW bike you're assumed to be smart enough to turn the headlights off before thumbing the starter...)

 

Ciao,

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On 2017-09-27 at 6:59 AM, JZH said:

Terry, where did you get that diagram?  The US-spec bikes (that is for the '98-'99) are slightly different from Deepee's (presumably) UK-spec bike, but it's a very nice hi-res wiring diagram nonetheless!

 

Ciao,

 

MadScientist posted that diagram as a layered pdf to the downloads section a couple of years ago, and added a similar one for the '93-'97 VFR750 a few months later.

5th Gen Super High Resolution Wiring Diagram

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