Fuelling Issues

[Jonesey]

Unusually, my vtr is giving me a bit of grief.
It has developed a couple of small problems, both with fuelling- the first one is that at anything under 1800-2000rpm the response has become a bit wheezy, once over this it goes fine.
The other issue is that it is running rich all of a sudden, especially at the top of the rev range.
I had the bike dynoed at total traction last week, and Mick said that the emulsion tubes had probably been worn oval by the harder dynojet needles, this is why an excessive amount of fuel is getting through.
Tickover at 1100-1200 is fine, it's just pulling away that is rough.
As usual, ANY input/ideas will be greatly appreciated- not really sure about carbs/fuelling etc.
Cheers.

[Stratman]

erm, new emulsion tubes then?

[warby221]

Tell you the truth I think they jetted the top end and upset the idle mixture when they had it on the dyno and then didn’t want to bother with having to take the carbs off again to correct it with a different idle jet

number 39 this jet sets the bottom end fuelling along with the mixture screw to fine tune the flow rate

[benny hedges]

you sure its not just your air filter is fkt?

[tony.mon]

Jet wear doesn't happen quickly, and so you don't notice it happening.
So have you changed anything else, serviced it, plugs, filters, anything?

[Jonesey]

Stratman, as far as i know the emulsion tubes are non replaceable?
Air filter is k+n, cleaned and re oiled 1 week ago
Tony- the oil and plugs also changed 2 weeks ago.
The dyno work was only a base run just to find out what the issue was, that's all he did to it
Mid to top of the rev range is still like a madman, just bottom 2000 rpm is a pain.

[sirch345]

Unusually, my vtr is giving me a bit of grief.
It has developed a couple of small problems, both with fuelling- the first one is that at anything under 1800-2000rpm the response has become a bit wheezy, once over this it goes fine.
The other issue is that it is running rich all of a sudden, especially at the top of the rev range.
I had the bike dynoed at total traction last week, and Mick said that the emulsion tubes had probably been worn oval by the harder dynojet needles, this is why an excessive amount of fuel is getting through.
Tickover at 1100-1200 is fine, it's just pulling away that is rough.
As usual, ANY input/ideas will be greatly appreciated- not really sure about carbs/fuelling etc.
Cheers.

Chris,
I've heard about this happening before, so I'd say a good posibilty. It would most likely depend on how many miles the bike has done with the Dynojet kit fitted. Take a look here;-
http://www.vtr1000.org/phpBB3/viewtopic ... sion+tubes

Chris.

[Jonesey]

Thanks to all for advice, now here's my theory-stop me if you think this is not the way to go.
I have got hold of a nice clean set of carbs (cheers baz) but upon inspection, they have also been fitted with dynojet jets and needles!
Now then, my bike has done just over 63k and as far as I know, they have been dynojetted for most or all of that time which equates to a LOT of wear.
The carbs that I have now are a lot newer, with less miles on them- so here's the question:
Shall I swap them over "just to see what happens?"
I have stripped them completely, and they are spotless and ready to go.
Once again, any input at all appreciated.
J.

[tony.mon]

Swap them over, it's only a couple of hours' work, and then you'll potentially have an answer to your problem.
If it doesn't cure it, you could try new jets and needles, either DJ or standard spec.

[sirch345]

Chris,
I agree with Tony, now you have the second set of carbs you just as well swap them over and see how she runs with them fitted,

Chris.

[Jonesey]

Right, what i'm going to do is transplant the carbs on saturday morning, and will report back the results.
Chris.

[sirch345]

Right, what i'm going to do is transplant the carbs on saturday morning, and will report back the results.
Chris.

Spanners and screwdrivers should be moving right now then

Chris.

[Jonesey]

Update.
I removed, stripped and cleaned my carbs, and discovered the front choke plunger was not returning when the choke knob was pushed in.
It was very dry and full of gunk, so I replaced the whole assembly with a new one and this seems to have cured the problem completely!!!!
It would explain the boggy running low down, and the astronomical fuel guzzling....
A few rides out will confirm it's cured.

[tony.mon]

Sounds like that was it, easy once you know what it is.....

[Jonesey]

It WAS the choke plunger, bike is now back to normal- even checked resistance at the pulse generator, which showed 581 ohms, spec says 600-620, although a little low I don't think it's a cause for concern/replacement.
Thanks for all input and comments, it's appreciated.
P.S. Bazza, I owe you a drink and a choke cable.