Hi i am totaly inexperienced with bikes and i have just bought a 91 vfr400r nc30. I havent passed my test yet so i am just preparing it so its ready for when i do. When revving the engine it kind of misses/struggles around 7000-8000 then after that ir seems to recover and revs normaly. Anyone know what this could be without me stripping it down? I am not that good with mechanics and just wondered is worth me trying to service it myself or take it to a garage for them to do. I know nothing of the history of the bike so i havent a clue when it was serviced or if there is anything seriously wrong with it. it starts first time everytime with full choke idles fine with and without choke. It has had a race can on it before i bought it and previous owner put the original can back on but it is blowing from where it was chopped?? anyone any ideas/advice/ help!!!!!!!!!!!!

i have enclosed a photo!!

Ta Kris

Hey chris, looks like a nice clean specimen... Before thinking this a problem, service the bike YOURSELF and change the air,fuel and oil filters first.. Could be a caked air filter upsetting the mix at that range.. Once its serviced you can go from there. Lighties in the background admiring daddies new toy?

it could be the can,do you have the race can?

the blowing could effect it also,i would get that sorted first.




wull

yeah get the exhaust sorted first, you may find it clears after a good ride.

my trackbike had the same symtoms the other week as i hadnt rode it for a while, it soon cleared.

nice bike

Hi, Thanks for the replies.Yeah im really pleased with the bike it has a few bits that need changing but overall i am pleased!! I didnt get the race can with it unfortunately. so im going to get a scorpion titanium oval i think. fit it and attempt a full service on my own including spark plugs, it cant be that hard can it????????? this will hopefully sort the problem out, if not i will have to take it to the garage because i reckon im at my mechanical limit!!

Kris

Spark plugs are a bugger on a V4, you have to swing the rad forward but don't be put off!!
Everyone starts somewhere and when you think about it it's just nuts and bolts, how hard can it be

Has it been stood a while? Might be that the carbs need cleaning out and balancing. You also might need to have the valve clearances checked, depending on mileage.

I managed to change the oil/filter/plugs and I'm a girl with no engineering knowledge whatsoever apart from what I've picked up over the years. I took the radiator right off, found it to be a lot easier and you have to change the water/coolant anyway.

My first NC30 was a 1989. I had the same problem. Have the jets been changed my first one had 110 jets in all carbs. I changed them to 116/118 combo and it relieved the problem. If you look up rick oliver he wqill be able to supply the jets.

Regards

Steve