Help please - bike problem this morning

Mr Badger

Mr Badger

Mr Badger

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Joined
27 Dec 2009
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Tale of puzzlement as follows:

My Yamaha Fazer 600, usually runs sweet as you like. This morning for no readily apparent reason when I hit 4000 RPM it gets rough as old boots and although it continues accelerating felt decidedly gutless travelling along the motorway. There was no problem when I rode it last week and today I couldn't see any warning lights or smoke and the engine seems to be fine at idle/low revs. Couldn't investigate further due to the joy of work, although I will need to ride it home later. I've got nearly a full tank - could I have got some dodgy petrol at Sainsburys? Does that even happen in real life?

Any suggestions as to what it might be/what to look for gratefully received!
 
Idk

When we're the plugs last changed and the air filter cleaned or changed? Does it start from cold alright? No flooding or difficulty starting?

I've never had any bad petrol cause any trouble but I've had a clogged air filter cause slight misfire at certain revs,cleaned it and it was fine

I tend to fill up at asda for what it's worth
 
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It was serviced about 6 months ago. Started fine this morning as usual, it was only when I got on the main road and opened it up that things started to go wrong. Felt even worse on the motorway, so giving it a blast didn't clear it. :rolleyes:
 
I'd check the easiest things first,its usually something simple

Like plugs or air filter,if you've ridden it in the wet recently spray all your ignition leads/caps and coils with wd40
 
I also had this for a few days.

Cleared iirc when I filled up again, I also use Sainsbury's..

Could just be coincidence, not sure. I just rode around the issue for a couple days whilst doing some googling, before I started ordering anything it disappeared.
 
Shimmy said:
I also had this for a few days.

Cleared iirc when I filled up again, I also use Sainsbury's..

Could just be coincidence, not sure. I just rode around the issue for a couple days whilst doing some googling, before I started ordering anything it disappeared.
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I haven't filled up again yet (no room!) however it does seem to be getting better by itself. Fingers crossed that this continues...
 
Maybe some dirt or something just got pushed through by the fill up? Maybe best to redex it and give it some vpower for the next couple of fill ups?

People say redex and vpower don't work, but it definitely made a difference on my Hornet.
 
I wouldn't have thought bad petrol tbf,dont think ive ever had that happen

but hope it clears up for you
 
In my last job I worked with a woman who's other half was a biker and drives fuel tankers and he said he'd never let supermarket fuel anywhere near his bikes.
Make of that what you will.

Doesn't stop me but I do tend to go for the premium stuff.
 
tom_e said:
In my last job I worked with a woman who's other half was a biker and drives fuel tankers and he said he'd never let supermarket fuel anywhere near his bikes.
Make of that what you will.

Doesn't stop me but I do tend to go for the premium stuff.
Click to expand...

Yeah, I've heard a lot of people say that they won't fill their car or bike with supermarket stuff. Never had a problem here and nobody I know has ever had a problem. Maybe over a lot of miles it'd make a difference?
 
Craig321 said:
Maybe some dirt or something just got pushed through by the fill up? Maybe best to redex it and give it some vpower for the next couple of fill ups?

People say redex and vpower don't work, but it definitely made a difference on my Hornet.
Click to expand...

vpower nitro+ definitely works on cleaning the engine out
its not a quick fix like some think.
have read lots of times, guys saying "i put vpower in once every few months to clean it out"
but it needs to be used all the time to get the real cleaning benefit, I also run an ignition advancer(so that was the main reason for using nitro+) .
For the last 8,000 miles I have used it 99.9% of the time and as the 100's turned to 1,000 miles the mpg slowly went up.
my bike never got in to the 60+ mpg(was around the low to mi 50s), now it rarely out of it or very high 50s if it does.

As for redex , it sorted my ex girlfriends cars misfire out
it had it over a month and wasn't going away by its self. 2 tanks of fuel with a bottle of redex sorted it.
 
If it's idling ok but running badly with little power under load, then it's either fuel or ignition.

Fuel could be starvation due to blocked filter/screen in the tank, kinked pipe, or a blocked main jet in one or more of the carbs. Clearly the idle circuit is working well enough.

Ignition could be either a plug, HT lead or a coil breaking down. Difficult to diagnose without substituting good parts in this case. You could try holding the HT leads whilst the engine is running to check for leakage...but I wouldn't recommend it :D
 
How old is the bike? Is it injection? Is it a vacuum tank?

If a vacuum hose is breaking down you wont get the fuel tap fully open
 
Stuttering at 4k, heh, must be contagious :p I'm going to be looking at my points and timing this weekend to see if I can get it to go away. Rain forecast for tomorrow though :(
 
First thing i'd check is the fuel filter if it has one, sounds like fuel starvation as the rev's go up so it's possible if it has got a filter and it's not been changed recently that it may have pulled through enough crap that it's restricting flow. May also be worth siphoning off the existing fuel and replacing it with some from another source, fuel contamination is unlikely, but cheap/easy to rule out.
 
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