hello , hope you can help.

[chiboyracer]

hi, back again after what seems an eternity. Just got bike back from my local bike mechanic , and he basically said he cant fix it.
symtoms. a shit to start. when it does go massive flat spot which is so bad sometimes it will not rev through unless lots of clutch slipping. if you get through it goes like blade on nitro.
mechanic been through carbs with a fine tooth comb, and a sonic carb cleaner and is 99.99999% sure problem is else where poss electrics. he recomend i buy another bike and swap bits one at a time till i find offending item. then replace that bit and sell donor bike. cannot realy afford that so was wondering if there was anyone in the west sussex area that could try my cdi box on there bike to eliminate that. due to dealer price dont want to buy one on the off chance. forgot to mention the bike ran fine for the first four years of onwnership, took it off the road to re paint and it was never the same again. is the uk electrics different to import ones , as mechanic said he tried another cdi but a few of the wires were different. thanks for reading, any help or ideas gratefully recieved. nick

[ibby4585]

what bike is it?

[CMSMJ1]

Welcome..

Sounds like your mechanic is pretty crap at orting bikes out.

You are going to have to get a Haynes manual and some time in the garage and it will get sorted.

Firstly - the simple things.

What settings has the bike got - is it a UK bike? Does it have a standard air filter and exhaust set up? What carb settings has it got - i.e What main jets and what pilot screw settings?

Does it run better on choke or off choke?

Have you checked the charging sytsem?

My first guess is that the fundamental carb/airbox settigns need putting to standard and then go from there. They are fickle bikes...but a mechanic worth his pay should not handa bike back without some decent diagnosis being done...

[Cammo]

mechanic been through carbs with a fine tooth comb, and a sonic carb cleaner and is 99.99999% sure problem is else where poss electrics.

No offence to your spannerman but I reckon it will be the other 0.00001% that's the problem. The cdi usually works or doesn't, there's really no magic component inside that will affect only the midrange performance (spark advance alters but won't cause your issues).

At least you know your carbs are clean!

Induction related is my bet. Is it running the bog stock standard airbox & filter setup????

More details please. These bikes are simple to sort IF you know what you're doing.


Edit: Didn't see CMSMJ1's post, the man is on the money as usual...

[chiboyracer]

sorry the bike is a vfr400rrl. it is a uk one. air box is standard as is air filter. jets and settings are standard as far as i know, did have a tinker a few years ago, set as per haynes. have not checked charging system, but did have a new battery a while back. have just about come to the end of my teather with it, hasnt been ridden reliably for about 4 years now. thanks for your help and guidance i just hope something works.
PS i quite agree about the mechanic but he didnt charge me much. would another set of carbs be worth a try, there seems many on ebay, not sure if there are different variants though. thanks again. nick
exhaust pipe is standard with alloy race can . been on there for years . put on by previous owner in late nineties and never rarely missed a beat.

[ibby4585]

Read Cammo's guide on carb settings and removal.its very easy to follow, it maybe a bit daunting to begin with but you will be able to do it. Once thats done you know in your own mind that they can be eliminated. Im no expert, and there are far more experienced people on here, but i would look at the carbs and spark plugs first!!

Kris

[mattjc]

I too have had similar problems with the wife's bike - to be honest the bike is a money pit, I've changed an awful lot of parts on it now, lower rad and fan, wiring loom (the previous owner butchered this fitting a manual fan switch, and it was full of water?), coils, modified an R6 reg rec, new rear shock (the old one leaked it's oil), and the bit that may interest you!

I replaced the carbs with a set I bought on here (apparently cleaned and balanced) and it never ran right... (I can't remember why I changed them but there was a reason?) firing on three until warm, sounded weird while running had them cleaned again and still the same, I was sure the carbs where good and that they weren't at fault - hence the coils and another set of plugs, so in the end my brother in law (a bike mechanic) cleaned and tidied up the original carbs and with out me knowing and popped them in and...

WOW the bike runs like a dream, no flat spots and never misses a beat, after almost giving up and getting ready to sell it at a massive loss, I now remember why we bought it in the first place.

So I reckon it'll be the carbs.

[Neosophist]

Older bikes are always expensive!

If you want something cheap to run get a new bike and trade it in after a few years and let somebody else deal with the problems :D

The V4 experience costs :/

Anyway..... UK Carbs are different to Jap carbs so I wouldn't go about getting a new set, strip yours down first and see what you have to work with, if their already cleaned properly you will probably just need to check float heights and pilot screws.

The rubber collars that join the carbs to the engine can also become brittle and leak air.

Electrical system is also a good place to start.. many electrical problems manifest themselves as runing issues, especially with Honda's Reg/Recs being made of cheese.

[theoutsider]

Follow the information in Workshop,start with carb,valve clearance,(spark plugs they might be the problem),I don`t think you electrics are fucked,and your mechanic is a muppet.
Sort out your bike by yourself as you will find it much easier if it needs something else in the future.
Rewiring is easy,do it if you think thats the problem.
I remember when I had my first 50 I had so many problems been to mechanics they all charged shit loads of money for temporary solutions,in the end I got fed up and I started doing all of it by myself,(never knew a thing about mechanics,but now I can hold a spanner in my hand and find a solution quick).Also it is ridiculos that he said you should buy another bike,tell him to give you a grand and after that you will buy one.I know mechanics hate our nc30s for some weird reason,but hey it`s a bike everything can be done.
I had a pig of a problem with my nc30 ,similar like yours,changed the plugs and bang everything back to normal.
Sorry for the long post.
Good luck

[quicksilver]

By the time you're done - it will have been cheaper to have taken it to a Honda dealer that know's what he's doing. You don't have to pay them to fix the problem, just cough up for the diagnosis. Dealers aren't cheap in terms of labour hours, but with an unridable bike and no experience with NCs, everything else will be a false economy. Don't take the pain in small doses - bite the bullet, find out what needs to be done and decide upon a strategy from there. Oh, and ask for your money back from your so-called mechanic.