Fueling problem pls help

[Phil-VTwin]

Have you fitted the dynojet kit yet?

The idle mixture should be set correctly, as per the manual with an external tachometer or by ear you could well be running rich if you havent set them.
What is the colour of the plugs?

[Pete.L]

No I start the bike outside the garage, and I do not use the choke, damn it is potent man, the fumes will kill me. Does it have anything to do with the mixture screws, mine are 2 1/2 turn out. Gerrit

What pipes and jets are you running?
That's too rich for std pipies and jets but it is about right for a base setting for open pipes and Dyno jet kit.
Also the choke cable can stick in a couple of places too. Either directly where they enter the carb, or at the One into two join.
I'd check the cables before messing up the fuel mixture.

Pete.l

[Gerrit]

Hi Pete!

There is a K & N filter on the bike and a 2 into 1 Yoshimura xhaust.

I have a Dynojet kit but have not yet installed it.

I did have the carbs off some time ago, and it seems the previous owner did play around, as the main jets has it's numbers filed off...and there is an additional hole drilled in the carb slides, that still retain the original needles.!!

Once the bike is warmed up, it really goes well, but fuel consumption is a joke 120Kms on a tank, but then that that is commuting to work in the week, hardly getting into 4th gear.

What do u suggest?

Gerrit

[sirch345]

No I start the bike outside the garage, and I do not use the choke, damn it is potent man, the fumes will kill me. Does it have anything to do with the mixture screws, mine are 2 1/2 turn out. Gerrit

If it's that bad outside the garage it must be running rich. A good idea too check the colour of the spark plugs (as suggested by Phil) to see if it's running rich on both cylinders, also another good idea as Pete says, too make sure both chokes are operating properly, make sure one isn't sticking on

Have you always had this problem or has it only recently appeared

Chris.

[Gerrit]

Hi Chris, it has always been like this, serious fumes when idling, and very poor fuel consumption.
Gerrit

[Pete.L]

Sounds like it's had a jet kit in it at some time.
Did you notice if the slow jets were original? If they are the std set up should be about 1 1/2 turns from full closed. Yours would need to be a bit richer because of the Yoshi pipe. Try 2 turns open and then give the bike a run and see how it performs. You can get it close by trial and error but a gas analyser is what you really need.
Needless to say, if you go too lean you risk burning out an exhaust valve.
Pete.l

[Gerrit]

Thanks Pete. Yeah, that did seem odd to me. The slow slow jets are original, the mains can be Factory Pro, the numbers are filed off, but the faint FP logo is visble. At the moment the mixture screws ae 2 1/2 turns out, I will try and go in a bit and try it out. Mad my own adjuster, works a charm, Must buy a gas analyser, will always be usefull, on the race car etc.

Up to how many revs do the mixture screws play a role, before the main circuit takes over?

Gerrit

[Phil-VTwin]

A gas analyser is ok but when the downpipes are joined together as the Storm's are, you will be reading the output of both cylinders combined.

Pete, if you disable the fueling on one cylinder at a time and run it on a single cylinder would that work better?

I used an external tachometer on mine today along with my new carb adjusting tool, i couldnt get the front adjusted, the revs were still rising when fully closed so i may have damaged the pilot jet when cleaning them out with a micro drill bit

However the rear cylinder adjusted ok and the meter registered the required 50rpm drop as stated in the manual before backing it out half a turn, the plug colour on the rear is good but still showing slightly rich on the front.

[Pete.L]

A gas analyser is ok but when the downpipes are joined together as the Storm's are, you will be reading the output of both cylinders combined.
True , I should have thought of that

Pete, if you disable the fueling on one cylinder at a time and run it on a single cylinder would that work better?
Nah! firstly it doesn't run at low revs when on one cylinder. Second, it changes the loading on the engine and will give you a false reading if you can make it run on one

I used an external tachometer on mine today along with my new carb adjusting tool, i couldnt get the front adjusted, the revs were still rising when fully closed so i may have damaged the pilot jet when cleaning them out with a micro drill bit

However the rear cylinder adjusted ok and the meter registered the required 50rpm drop as stated in the manual before backing it out half a turn, the plug colour on the rear is good but still showing slightly rich on the front.

Is that slightly rich on the front with the screw full in?

[Phil-VTwin]

yes still rich and screwed right in, i think what happened to that jet is the hole got enlarged when i was cleaning them with a drill bit, thats before i tried the blow torch to clear the 'varnish'

[sirch345]

yes still rich and screwed right in,

I bet I know what Pete's answer is going to be to that

Chris.

[tony.mon]

Just a few thoughts:
It certainly seems like someone's fitted a DynoJet kit as no other jet kit requires the slides drilling.

But I've never known anyone to uninstall a jet kit- why would you?

Lastly, numbers filed off jets??? what would that be about? Losing weight? (bit obsessive, IMHO)

I'd be tempted to buy some new jets and fit those to see what difference there is.

Beware that DynoJet use different sizing to other mnfrs, so their 190 isn't the same as other people's, like Mikuni or other carb mnfrs. See other threads for info.