Vfr400r 1993 - Can't find the problem

[moT]

i started to strip bike down for F3 so indicators, lights, speedo put all overfolwn in bottles etc then i gave it an oil change took it for a test ride and it ran like a sack of shit it runs fine until about 4500rpm but when i rev it higheer it does not pull like it did before it does not accelerate under load first i thought spark plugs as they were pretty fuked anyway so i changed those and it still ran the same. i hadnt tamperd with air fuel mix but i have been runnign it without a filter for a while so put one in and still the same checked the carbs there clean all the leads are working they all spark i have a hunch its the ignition timeing from the little black box but i dont know help me !

[k14]

you sure its not a dodgy reg/rec? The nc30's are infamous for having issues with them.

[moT]

hmm i have replaced it before with an aftermarket one when my old one did die it sorta had the same symptoms i replaced it about 2 years ago maybee because i took lots of the electrical stuff off it put too much load on it and fried this one too i hope not those things aint cheap but ill check it out. what does the reg rec do?

[k14]

It regulates and rectifies the voltage :msn-wink:

[crazybigal]

that wouldnt make it run bad, would make the batt either fry or under charge.

sounds more like a fuel pump problem or fuel line blockage
i had a NC29 do this, the new fuel line i put it had too much of a bend in it, bike starved of gas at 10,000rpm
I start by checking your fuel flow and filters, tank and external.
check the vacum lines as well.


you sure its not a dodgy reg/rec? The nc30's are infamous for having issues with them.

[HDTboy]

Try reconnecting the instrument cluster.

If you've got money to throw at it, take it into GP Honda, they know NC30s inside out.
If you don't have much money to throw at it, I could come over and have a look at it for you tomorrow. If I fix it, you pay for a tank of gas. If I don't, you don't.

Gavin, 021530483

[moT]

ok well i might take you up on that offer i got it at farm and trail te puke right now they are having trouble finding the problem its costing me a bit how well do you know nc30s

[moT]

what is a good way to check if its starved for fuel or air?

[crazybigal]

it wont be air, unless you blocked up the filter, what were the plugs like? all black and wet?
check you fuel filters, you prob have an aftermarket one in there, could have crap in it, check you tank one, if you have an empty tank take the inside tank one out, f it has one!.
also make sure all the vacum lines are connected up to the carb and no air leeks. is the fuel pump making any noise?

[mark247]

The problem with Toms bike is resolved. It was taken to Honda GP and after an hour they realized it was the speedo disconnected causing the problem. $100 or so to find out he had unplugged the speedo! LOL. I think even i would of been able to figure it out, but i didnt know he had just unplugged the speedo, i thought he had ridden it since then. oh well. fixed now.

[moT]

Well thanks everyone for your help the speedo was the last thing on my mind i knew it would be something stupid. even tho i started to believe it was valves or something bad which would of cost me $600+ but its in there now getting rejetted because its running very lean and im getting restrictor removed so not too much of a loss.

[imdying]

*cough* I think it's time for everyone to bling up HDTBoy *cough* :yes: