02 Fazer 1000 cutting out

[chaz46]

Ive read through a couple of threads here. very informative but Im partly confused.
I picked up the fazer as a spare engine for my 02 R1 track bike, only difference tuning and carbed against the Fi R1.


,the bike was stood for a couple of years had some rust in the tank which Ive cleaned out and had two filters, now just the one. Carbs had been off and cleaned.
The bike will cut out after standing for 10 mins or on a short ride. Will then start right up again, straight away.


The ECU is cool, the battery gets 14.5v dropping to 13.5 with all lights on  and heated grips. BUT, the fan cuts in after 30 seconds, the motor isnt warm yet and the voltage then drops just below 13v.
could the fan sensor be faulty? would that cause the engine to cut?

[robbo]

The fan cutting in after 30 secs is about right and is quite normal. Think I read somewhere that the fan blades, being made of plastic could otherwise become distorted if the engine is left ticking over for a lengthy period. It also proves all’s well with the fan operation.  Will have a check for the definitive reason.

[chaz46]

thanks Robbo, the R1 only comes on when temp hits around 100 degrees, more or less same engines.

[robbo]

It’s just part of the normal start up “procedure”, to protect itself, which one wouldn’t notice if the bike was started and ridden away immediately. Fairly certain the fan will stop when the bike’s put in gear, but have never checked myself.

[PieEater]

Fan behaviour is normal as detailed in the FAQ - "The radiator fan on the Gen1 will switch on once the engine has been started and the bike left in neutral for a short time, the fan will turn off once the bike is put in gear. This is by design, Yamaha have said it is to prevent the fans blades from warping due to heat from the header pipes."

If the engine is cutting out around the same time you'd probably be looking at fuelling, what are you doing with the choke during start-up / idle? I would also check the FAQ regarding carb issues.

[chaz46]

ok, first time Ive come across the fan procedure, tbh, apart from a RS100, and the R1 these are the only two Yamahas Ive had in 50 years riding. Although I have worked on many other marques and never had it happen before. I know some bikes run right through the bikes system in the first few minutes including fan test but normally shut off.
This one stays on as far as I recall, will check tomorrow.


I have discounted fuelling as it shuts down without any starvation and will start up straightaway .The filter is always full even when cut out.


could it be the sensor if the bike cuts out at the same time as the fan, then it resets itself?

[Gnasher]

FZS1000s don't have ECUs, they have an igniter unit/box in the tail hump.  As far as I'm aware there's no connection between the cooling fan cutting in/out and the igniter box, the bikes system isn't closed loop, it has a now old fashioned CDI type system, I won't go into to details. 

From the sounds of what your describing, you've got water ingress either in the ignitor box, starter relay, staring circuit cut off relay. it's also possible there's an issue with the rectifier/regulator.  Remove all the plugs to all of them, check for corrosion, clean and try if that doesn't work it's highly likely there's water in the ignitor box.  This will slowly heat up causing a vapour that will short out the unit and stop the bike, it condenses on cooling down the bike restarts, this will happen with alarming time accuracy 20/30mins or so.

It happens to proper ECU's, they have to be opened dried or replaced. 


Check all the connections and test all the components first.  If they're all ok, swap the ignitor box, you can try and borrow one from a known running bike first, to replace they're approx £80 second hand.       

[PieEater]

Also the bike has a sidestand switch which will cut the engine out if you engage gear with the sidestand down, so if you are starting the bike on the sidestand leaving it long enough for the fan to kick in and then engaging gear with the stand down the fan will stop because you've engaged gear and the engine will stop also as you've engaged gear.

[chaz46]

not had a lot of time this week, just been out and started it. fan comes on and when gear engaged, stops. Back into neutral and after a while fan comes on, then goes out when gear engaged. SO presumably correct.
While doing this, the bike cut out. Clutch straight in pressed button and starts again.. baffelling, could it still be carbs?  could the fuel pump be on the way, there is fuel in the filter before the pump?
thanks

[Falcon 269]

If it cuts out dead, no misfiring or stuttering prior to stopping, I'd say it's electrical and not fuel-related.  Particularly since it restarts immediately on the button, meaning there must be fuel in the carbs.

Focus on electricals, plenty of suggestions above to point you in the right direction.

[chaz46]

back in the land of the living, no work or hospital ..
bike has been sat on the ramp running for 10 mins without stopping , so, I think the problem has cleared as double or treble the normal cutting out time.
What I have noticed, is , when the filler cap is lifted there is a rush of air, presumably vacuum, is this normal as Ive never had it before or on other bikes..

[Gnasher]

No, the breather system is restricted/blocked somehow.  This will cause cutting out but it wouldn't restart, as you've stated it does.