Help - Bike won't rev past 5000rpm
 

On my way home today after a little run out my bike started dying on the motorway and was reluctant to rev past 5000rpm, I pulled oved and saw nothing was wrong and the bike run fine on tickover. Tried accelerating again and it runs fine in the low revs but wont rev past 5000rpm. Got home checked the air filter wasn't blocked, checked and changed the spark plugs because if feels like a fuel starvation/misfire/running on one cylinder problem but all to no avail. I checked the coils were connected and there were no fuel line or breather hoses kinked. I can't understand it as the bike runs fine at low revs and i was able to limp home shortshifting all the way. Help me OB1 your my last hope. Any ideas of what to check next will be welcome.
BTW if's a "curvy" '99 model. :D

Had that the other week... no explanation either... eventually went back to normal but only after backfiring continually for about 2 miles... Certainly one way to keep the cars off your **** :lol:

Changed can back to race can, changed both plugs and cleaned air filter and its not done it since

Is it misfiring on one pot? Put your hand *near* each exhaust pipe close to the head to find out. Might be a stuck choke slide if it's not electrical.

easier way than riskng burning yourself is to spray some liquid... (non flammable :wink: ) or spit on each pipe...

No it is firing on both cylinders and the choke cable was replaced 2 weeks ago.

check the spark plugs?

Maybe carb-icing? Did it do the same once you'd started it from cold?


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Nuntius - I did change the plugs.

Jonboy- It started fine today and was running OK for about 15 miles before it happened. It has also run fine on colder days than today.

Thanks for the help chaps, I hope it's not a trip to the dealers as I'm skint.

Possible crap blocking up the jet [s]. They kick in about then don't they...

Carb icing isn't just controled by the temperature, if it's cold and damp that's far more likley to cause a prob than cold and dry. Try a fuel additive such as the silloline or fuchs ones to see if this helps. Also check the connectors to the float bowl heaters are on securely.

TBH the fact you had the choke replaced 2 weeks ago would put it on my suspect's list, always look at things that have been done recently 1st! When changing the choke cable the carb heater cables may have been knocked loose, they're not a million miles away.