New Nc29 owner please help

[Carcass]

Hi all, ive just got my cbr400 on the road but it seems to be "fluffy" through the gears.
It will pull in the low revs but the second you get to higher speeds/rpm {60-70mph 8k-9k} the bike will bog down especially in 3rd gear and above {for instance today when i was travelling i clicked into 5th gear and opened her up but she started to "flutter" with the throttle open over half way and bogged down and lost revs if the throttle was "pinned" it was as if she had fuel starvation or something} also when idling if i lift the sidestand the revs raise up an extra 200 to 500 rpm {once warm it seems to level out}
when i bought the bike i treated it to a new set of plugs , cleaned the carbs and set the air/mixture screws to the settings in the haynes manual, new fuel filter and a motrax mph converter.
Has anyone ever encountered this before? or has any idea to resolve it ?
im completly stumped on this one

[LUCAS]

Ok you say you have just got the bike on the road; have you ever rode it before this point and it was ok?

Do you know whether the jetting is standard?
Is the air box standard?
What exhaust system have you got on?

I had it where i fitted a Moriwaki system and at 8-9k revs it was way too rich and was horribly jetted. I was running a dyno kit on standard settings at that point.

[Carcass]

Ok you say you have just got the bike on the road; have you ever rode it before this point and it was ok?

Do you know whether the jetting is standard?
Is the air box standard?
What exhaust system have you got on?

I had it where i fitted a Moriwaki system and at 8-9k revs it was way too rich and was horribly jetted. I was running a dyno kit on standard settings at that point.

Hi Lucas thanks for the quick reply, ive only just started riding it {this is my third day}
The jetting is standard so is the airbox {the air filter is not new but very clean}, it has a stainless steel exhaust system and exhaust {believed to be a micron system}
many thanks Chris

[Marcus127nc29]

is this bike black and white nc29?

[Carcass]

is this bike black and white nc29?

No its blue and streetfightered {still have original fairing but the renthal bars take the weight off my back}
Just an update, went out today and decided to take off the motrax mph converter and it seemed rev more freely, then all of a sudden it cut down to two cylinders but when acceleratind it would fire on four again but then when i leveled off the throttle {ie held it at 30mph} it would cut down to two cylinders i thought this seemed really odd i was in the country lanes so i couldnt really stop anywhere, but the oddest thing was after riding for about 5 mins with this going on i think i hit a bump in the road or something and she was running back on four cylinders again as if nothing had happened!
I now believe its a electrical problem or a restriction going bad etc

[LUCAS]

is this bike black and white nc29?

No its blue and streetfightered {still have original fairing but the renthal bars take the weight off my back}
Just an update, went out today and decided to take off the motrax mph converter and it seemed rev more freely, then all of a sudden it cut down to two cylinders but when acceleratind it would fire on four again but then when i leveled off the throttle {ie held it at 30mph} it would cut down to two cylinders i thought this seemed really odd i was in the country lanes so i couldnt really stop anywhere, but the oddest thing was after riding for about 5 mins with this going on i think i hit a bump in the road or something and she was running back on four cylinders again as if nothing had happened!
I now believe its a electrical problem or a restriction going bad etc

There is a certain mod you can do electrically to get around the 112mph/ 180mph limiter. The other option is the kph/mph mechanical converter thus never reaching the 180 part on the clocks like you have done. It may be worth looking at the wiring around and to the back of the clocks. Other people will know this exactly, but its to do with these connections, that if there is a disconnection it puts the bike into what seems to be referred to as 'limp home mode' cutting it onto 2 cylinders only. It's about the 8k revs mark on the VFR/ RVF's and this may be the case with the CBR's. Some 'mods' are done with such bad workmanship it's beyond belief! Worth a shot. Like i say, there are some people on here, im hoping who will pick up this thread who will give you a definite answer.

[Carcass]

Hi Lucus, i took the clocks off this morning and dismantled them to see if there was anything floating around inside the clocks {sadly not} i tried searching many forums to find out the specific procedure of removing the metal disc inside the clocks but i cant seem to find any info.
I did however find this: [tag]http://i46.photobucket.com/albums/f115/ ... ResMod.jpg[/tag]
I thought i should upload it just incase anyone else is after the info.
Thanks Lucas for all your help, will let you know how i get on after ive done the mod.
Cheers Chris

[leopard_pagan]

as i mentioned in PM, if the MPH restrictor was kicking in, youd NOT get over 30mph, youd NOT rev higher than 5,000rpm.

the fact that all 4 fire, then cut to 2, then back on 4 sounds more than the limiter to me. loose wires are coming to mind here.
Start with the coils, check the HT leads.
now check the MPH limiter wiring,, from the back of the dash right back to the CDI unit..
your looking for worn, cut, bare, eaten, shitty wires.

also check ALL earth points on the bike..

[Carcass]

Thanks leopard_pagan, well so far ive tested the coils and they seems to be fine.
I tested the three wires between the speedo restriction and cdi for continuity to see if i had a break in the wires and i found that orange and blue wire was fine but the brown and black wire had continuity at the cdi on five wires {b,w y,bl bl,y g} aswell as the green wire {g b,w y,bl bl,y and light green} im not to great at electrics but can anyone confirm that having continuity at those five wires at the cdi end of the loom is right {before i start pulling the loom apart looking for a bridge or something}
Thanks Chris

[leopard_pagan]

dont pull loom apart to check, just trace from one end to the other visually/feel if you can..
do you have a diagram?
i will PM you a link to the L&R model diagram.. as thats all i have, but gives you an idea.