hi all, new to all this,

just got a vfr 400 nc30 1990,
it don't run well at all, will only run smooth with choke on,take the choke off and it runs but very rough,
almost like its misfiring all the way through the rev range
any help welcome
thanx martin

Start with a service, oil, plugs, filter, then if it persists go from there.

If the choke solves the poor running the air/fuel ratios may be wrong but get some fresh plugs etc in before you take it somewhere to be set up as if its been neglected by previous owners it will suffer.

i have done an oil and filter change, air filter coming in the week, and hope to have enough saved up for the plugs by the end of the week 13quid a shot
see what happens then
thanx martin
any more advise would be much appriciated

If the choke clears things up a bit then its probably running lean at other times.

Sounds like the carbs need a full clean.

Take them off, and blow out all the pilot jets, main jets and emulsion tubes. Set the float height and pilot screws at the same time. The haynes manual covers most of this.

Stickshift wrote:If the choke clears things up a bit then its probably running lean at other times.

Sounds like the carbs need a full clean.

Take them off, and blow out all the pilot jets, main jets and emulsion tubes. Set the float height and pilot screws at the same time. The haynes manual covers most of this.

as stickshift says,definately sounds like its running lean.fuel getting blocked somewhere.

does it run hot at all?this is a usual sign of a bike running lean.


wull

hope to have enough saved up for the plugs by the end of the week 13quid a shot

email rick oliver on here, i got a set for £38.

much cheaper than normal as you said.

all thanx for replys

i have found spark plugs for the vfr £34.32 for 4, thats about the best price i have found
http://www.mister-solutions.co.uk/er9eh ... -455-p.asp" onclick="window.open(this.href);return false;, just type in the plug number (er9eh)
£8.58 each.
going to clean the carb out tonight will let you know how it goes,

one more thing i have noticed the front of the air box has been hacked off is this some sort of air box mod??

forgot to say the bike does seem to run hot, and what jets should i have in it? (the bike has got a micron can on it)

got my ngk plugs from ebay, £31.50 all in

started taking the cars apart and all just full of crap, cleaned all of that away and found in the front a 115 main jet and 35 piolt jet, in the rear is a 118 main and a 35 piolt is this right???
thanx martin