Battery terminals are tight and there's no fuel pump - gravity fed. Hadn't really thought of electrics as I'd kind of sub-consciously linked the problem to my carb cleaning adventure but I guess it's possible. In fact, there is an annoying rattle coming from somewhere under the fairing which I haven't been able to trace (yet). Makes me wonder now whether the two things are connected (or disconnected, if you see what I mean).

 

Hi All,

I saw this thread, and just had to reply. I bought a CBR1000F last week that had been in storage for 5 years. After changing the plugs and refreshing the fuel, she started. The problems I am having are very similar to the ones KMCBR1000FM has. If I try to open the throttle slowly the engine stalls. If i open it up rapidly, the engine sounds rough, like running on 3 cylinders, or knocking severely, but at least she revs up.

Looking at this thread I am now convinced that I will need to clean the carbs. Basicly this post is a big thank you for all the good advice and comments!

I will post the result when the carbs are cleaned as well. (not ment as a post-hijack).

Cheers Gents!

 

I cleaned the carbs yesterday, and what a difference! 2 out of the 4 idle-jets where blocked. I used a needle to push the hole open again(compressed air was not strong enough).

At the moment the bike runs very well. It is scary-fast!

The only problem I have is that when idling, the bike only uses cylinder 1 and 2(exhaust 3 and 4 are cold). the moment the RPM comes above 3000rpm, all cylinders join in. I am suspecting the rubber flanges that connect the carbs to the head.

Anyway, the carb clean did make a massive change!

 

KMCBR1000FM, very glad to see that you have completed your carb cleaning work and the bike is on the road again!

 

Groceries (and others) , yes my bike is back on the road but as indicated in my 06-05-2018 12:03 post above there remains a problem I'd like to resolve if you or anyone else can offer some more help. Sometimes (but not always) when I ride over a bump or hole in the road there's a split second loss of power and a backfire or just a backfire and then everything continues as normal . Is there any idea what could be causing this ? I wonder if it could be something in the carbs that is sticking and then becoming unstuck with a sharp jolt?? It doesn't appear to be electrical as I've chased that possibility out of the picture.

 

Groceries = Groceries! Damned predictive texting.

 

Yeah I chuckled when I saw that! Did you check your spark plug wires and ignition coils to make sure everything is snug. When you put the boots on the plugs they should click in a few times. Other than that I would have no clue what it could be.

 

Yes, checked the electric connections and all seems good. I just wonder if something is still sticking in the carbs and whether that could cause these symptoms.

 

dunk the pilot jets in a carb dip basket and then blow them out if you have the inclination. Also clean out the other passageways with carb cleaner. They are very small and clog easy. Hopefully your floats and needle/seats are ok.

Don't forget to use gloves and a well ventilated area.

 

My gut: I still think it's electrical, just cause there's really nothing in a carb that would stop working when shaken, and if it did bog down it would want to cough and sputter and die slowly, not drop out all at once. It's also weird that it would backfire and start back up a moment later. To me that sounds like a temporary loss of spark, ie the cylinder still gets fuel, then when the spark comes back, it preignites

By all means, check out the carbs if that's what you're thinking but to me if they run and idle well normally, it sounds to me like they're doing their job

I'd check the engine stop switch and ignition switch - instructions in the manual but most switches are either a continuity check when cold or voltage when on - and if they are good, I'd check out coils and wires as Gronk says. A cheap spark tester would be your friend. Try gently wiggling the harness/wires while idling. If all four cylinders are dropping off, it points to ignition module, electrical, or switch. If one or two cylinders are bad, it points to coils/wires/spark plugs

What jogged my memory is a thread I'm subscribed to where the OP had a similar problem and turned out to be badly routed wires on the ignition switch: