F650 missfire

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TR80
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F650 missfire

Postby TR80 » Wed Apr 24, 2019 7:00 pm

Mate just bought a 2004 F650.
Seems pretty good overall but just suffers from a slight missfire on opening the throttle coming out of roundabouts etc.
Not all the time, maybe three or four times on a 60 mile trip.
(Went up the Llangollen Horseshoe Pass with no problem).
Doesn't cut out completely - picks up on change down or backing off the gas a little.

Could it be he's not giving it enough revs as it's his first single?
Or, simply too high a gear?
Could it be more serious - Fuel injection / a sensor?

The swop from a 600 Honda may be taking a bit to get used to!

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george baker
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Re: F650 missfire

Postby george baker » Thu Apr 25, 2019 9:39 am

Hi
yes it could be any of those things, there are only 2 options as I see it from what you have posted
1 get someone else to ride it
2 good service, Plugs, Points, Carbs, filters (I know -- but you know what I mean) and every connector.

From what you say it could even be the ignition switch loosing connection

Where in England are you based?

George
Member 21, R100R, and an unused K75

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windmill john
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Re: F650 missfire

Postby windmill john » Thu Apr 25, 2019 10:38 am

Does it have an after market exhaust which may just be a little to open, weakening the mixture? But you'd notice that more on the overrun.

Of course if he's just bought it, worth checking all the service bits, air filter, plugs etc. Check HT leads.

Depending on model, are you sure it's fuel injected? If not, duel carb strip and clean.
http://www.kittos.co.uk
Best roads: 623 Burgos to Santander. A back road to Metz; can't remember which!
Bumble, my 700 Transalp.
Sold my Airheads, what an idiot, but Honda is also great.
Too many bikes have come and gone, trying to be sensible now!

TR80
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Re: F650 missfire

Postby TR80 » Thu Apr 25, 2019 4:05 pm

All good comments, thanks.
I also think it's worth replacing the 'easy' bits first then seeing what happens.
Spoke to him and he's already come up with several things like plugs etc. (youtube)
Was a suggestion of disconnect battery to reset the engine management.
Maybe a loose ignition connector.
Bike is injection and came with record of plugs etc fitted last year, less than 1000mls since then.
He's going to work through the list of 'easy' checks in the next few days.

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Galactic Greyhound
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Re: F650 missfire

Postby Galactic Greyhound » Thu Apr 25, 2019 7:29 pm

You might also try some Redex Petrol System Cleaner treatment (Halfords).
I do this annually on my 1996 R1100RT at the start of the season and usually again nearer the end.
The amount I use per treatment is 50ml/24 litre tankful - I usually brim the tank before a run and add the whole 50ml in one go.
Never had any injection problems or taken the injectors out in 22 years.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

TR80
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Re: F650 missfire

Postby TR80 » Sun Apr 28, 2019 7:26 pm

I'll suggest Redex to the owner. Even if it doesn't cure the problem it'll clean the system.
I did a bit of site searching and came across sidestand switch issues - that's an easy check to do so will send him the link.

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windmill john
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Re: F650 missfire

Postby windmill john » Sun Apr 28, 2019 8:59 pm

Try tying up the side stand for a decent trip and see what happens. Bouncing over bumps made my F800 do the same, so I strapped it up to finish a 300 mile trip. When I got back I cut off the switch and bypassed it.

New switch £130. S/H switch £45. My job - free. For everything else there’s Barclaycard :grin:
http://www.kittos.co.uk
Best roads: 623 Burgos to Santander. A back road to Metz; can't remember which!
Bumble, my 700 Transalp.
Sold my Airheads, what an idiot, but Honda is also great.
Too many bikes have come and gone, trying to be sensible now!

TR80
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Joined: Sun Jul 19, 2009 11:37 am
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Re: F650 missfire

Postby TR80 » Tue Apr 30, 2019 8:28 am

Thanks 'Windmill John'.
Actually it was your original post I found and have passed it on to him!


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