New to VFR 400

[ibby4585]

Ok Cool .

So exhaust system is?
Jetting is?
Mixture screws set at?
air filter standard oem?

once thats all confirmed then move on to charging system inc battery
then electrical/ignition including coil packs and cdi

[Cammo]

right a quick update new plugs arrived today but them in fired up fine let it idle and warm up for a bit then gave it some revs

How long is 'a bit'?

Until the water temp is hot these bikes often don't like to rev in neutral, pretty normal. Take it for a ride and see how it goes.

[pete_vfr]

Hey all exhaust system is full MHP,standard Jet sizes, mixture screws set 2 and quater turns from fully in and air filter i think is aftermarket but not sure what make. Ive checked coil packs, spark and pulse genorator resistance as per haynes instructions only thing i did see while looking at the electrical side of things was, the plugs that come out the ecu the one plug goes straight to pulse genorators but the other plug instead of going straight into the loom it goes into a sealed unit that has HRC Not For road use writen on it....this isnt in the haynes wireing diagram so im abit unsure what it is?? any clues.

[pete_vfr]

Just done some reading and am pretty sure its just a hrc derestrictor on to the next thing then..

[ibby4585]

Hey all exhaust system is full MHP,standard Jet sizes, mixture screws set 2 and quater turns from fully in and air filter i think is aftermarket but not sure what make. Ive checked coil packs, spark and pulse genorator resistance as per haynes instructions only thing i did see while looking at the electrical side of things was, the plugs that come out the ecu the one plug goes straight to pulse genorators but the other plug instead of going straight into the loom it goes into a sealed unit that has HRC Not For road use writen on it....this isnt in the haynes wireing diagram so im abit unsure what it is?? any clues.

I think you need to get some pics up of what you have got.
1: I'm fairly sure MHP only do half systems
2. There is no way standard size jetting is sufficient for the above
3. The HRC is a desrictor unit
4. A modded air filter is not a good idea.

Just one of these things would give you the symptoms you are describing.

Take some pics of the exhaust, airbox and filter and cdi unit.

Then we will go from there, its easy to sort out you just need to work through it.

Kris

[pete_vfr]

Thanks for all that info mate, ok ill get some pictures taken the weekend are they easy enough to put on here?? the guy i brought it off said it was but i take you word over a guy trying to sell. I let it warm up this evening and it made a big difference shot up to 14k no problem tho im sure could be even smoother i think with your help, why is air filter an issue?? what kinda jet sizes would you sugest for that set up and keeping in mind im putting it on the track? Thanks for your help ibby what kinda bike and set up are you running? cheers all

[ibby4585]

Hi.

He might be right, but I'm sure MHP only do half system but hey that's not the issue, the issue is to get it running right.

I've never run a track bike but I've fiddled about with settings on my NC's for fast road riding, but there are plenty more knowledgeable people on the forum that can give you advice on track settings.

My advice would be set the jets and carbs to the exhaust. My suggestion would be 122 dynojets all around, drill the slides if they haven't been done. Mixture screws as per Cammos advice on half systems (forgotten what he suggests)

Then move to the airbox and filter. Get a standard oem filter and check the airbox is standard with snorkel on the end also check you have the rubber flap fitted in between the headstock ( search for rubber flap on here).

Remove the piggyback HRC cdi and just use the standard cdi. Once all that's done get it warm and use it as is for a bit, it shouldn't be far out. Then once its running right you can start trying different things.

If you don't do the above I think your in danger of following on from someone else who might have struggled with setting it up.
Hope this makes sense.

Kris

[Deviant400]

^^
you defo want to try return everything else to stock as much as poss that way with a base setting you can rule out a lot of stuff and get the bike running well and then you can start to make the changes you want, until then i think you will struggle to pin down the prob

[pete_vfr]

Thanks guys ill check it all out the weekend, the jets i got wront they were 118 all round, these bikes sound like they need alot of love to give you the joy lol, am enjoying all the info and finding out everything about it sounds good so im sure these little bits will get her back to her best.

[mo haggs]

Just to throw in a different perspective,
If you are only going to be on track id remove the airbox/filter altogether and fit bigger jets to suit.