Carb Mixture Screws

[Dead Eye]

Possibly a useless topic and redundant question, BUT

Is it actually possible to adjust the fuel mixture without having to remove the carbs?

[reillypadraig]

Yes you can small Philips head out if a set should do between your fingers.

Cylinder 1,2 and 4 are easy number 3 is a right pain but I ended up just using the long flathead and pushing it in the direction I wanted, couldn't find anything to work, some guys said jewlery screwdriver and bend it but I didn't go that far,

Why may I ask do you want to adjust them? First of all, after 3 months of me playing with these screws I should know by now that they only adjust the idle. Basically adjusting the amount of vacuum allowed into the float bowl and with that adjusting the amount of fuel to follow, as you hit the throttle it moves to the cutaway on the slide then the pilot jet then the main jet the more trottle you give.

So I guess the idle is all that's the problem yea??

[unfazed]

Come on now Padraigh, you were just screwing around  :rollin

[Dead Eye]

Yeah, I think I've gone completely mad... I can't remember the name of the darn screw but I'm pretty sure its underneath the carbs (hence my dilemma) which adjusts the amount of fuel flow

I remember the value which is typically 2.5 turns out but forget the name - thought it was mixture screws, but as you rightly point out, those are for balancing.

The bike is running particularly rich I believe to the point that I think its holding it back and destroying fuel economy, so wanted to experiment a bit. I'm guessing its probably carbs off again

Offending screw is highlight below - managed to find a historical photo on my phone

[packie]

I got a cheap screwdriver kit for watches/glasses ect. Instead of angling it which would be impossible as it would snap, I just hacked it in half. I marked one side with tipex so I could see how many turns I was doing. It had a grooved handle with a good grip so it worked a treat. Here is the size both close up and at a distance........

[Chris]

Sorry, ignore me. I need to go to bed.. haha. 

[Dead Eye]

That is actually a pretty good idea I'll have to see if I can fiddle around as I have several of those types of screw driver in my arsenal

[packie]

....you might need this too!

[Dead Eye]

Sorry to show my ignorance but isn't that screw you've highlighted the float bowl drain screw?

Nope, this is float bowl drain screw as far as I am aware

[Chris]

cheers buddy 

[Dead Eye]

Haha, you're welcome

[packie]

Sorry to show my ignorance but isn't that screw you've highlighted the float bowl drain screw?

Nope....there the ones that are angled out both left and right with the drain hole under them

[Chris]

Thanks guys  8)

One thing I've not really fiddled with are my carbs... yet. going to check, and balance them if needed, once I've got my new exhaust and Air filter in.

Chris

[unfazed]

That is the pilot set screw also often called the mixture screw (first pic) as it adjusts the mixture from idle to about quarter throttle. The setting is 2 turns out from fully screwed in, lightly, otherwise you may damage the taper. 2.5 turns out will make it run rich at idle. If set wrong like 2.5 turns it can make the bike run badly below half throttle which is about 5000rpm as it has to clear the plugs of carbon from the over rich running before picking up on the main jet properly. (Might be reillypadraighs problem) On the fazers it adjusts the fuel flow in the pilot jet circuit. It has nothing to do with vacuum which is controled by the idle screw on the left side of the carburettor bank and the throttle with your right hand. The main jet and slide needle control the fuel flow from quarter to full throttle.The more you open the throttle the more vacuum created in the inlet tract.
Remove the carburettors and set it to 2 turns out which is 2 x 360 degree turns. You can adjust them in situ, but it is very difficult to confirm the accuracy unles you have CO2 meters. They are set at the factory using CO2 meters plugged into where the bolts are on the downpipes. Which is why they may not be exactly 2 turns but very close to 2 turns. When setting up the fazer carburettors 2 turns is the start point.

[Dead Eye]

Mine are currently at 3 turns out, which is why I figured this was the problem. When I took them out originally when I cleaned up the carbs, they were mixed between 2.25 and 3.5 so all over the place. I'll be setting them all back to 2.25 when I get the chance and see what happens. I need to get round to buying new plugs ideally but money is short enough to prevent me dealing with this yet

[unfazed]

Ccommon problem usually made by people who have no idea what the screws are for. On many of the older pre vaccum type carburettors the screws controlled the air setting not the fuel setting and were set to 2.5 to 3.5 depending on the model of bike.
Normally if the screw are on the air box side of the carb they control the air and on the engine side (like the fazer) they control the fuel
Take them down to 2 and work from there. Make sure your air filter is clean and clean up the plugs if you cannot afford new ones. Soak the plugs for about 15 minutes in petrol and then brush off any soot deposit with a stiff tooth brush and they should be ok for testing. Start it up, take it for a spin and get it good and hot. Should be a big improvement when you come back. Now balance the carbs set the idle and finally set the TPS

[Dead Eye]

Yeah, most of my knowledge has been gained by reading these forums over the past 18 months - its an invaluable information resource. I do my best to read every post in every topic in the 600 forum

Thanks for the advice, I will most likely replace the plugs / take them out when I am prepared to have the bike off the road. The reason I say this is that my old red one had an issue where the previous owner had done the plugs up so tight that it snapped in the head when it was removed and I'd rather not have that happen again... Obviously I'll be cautious but I don't want to risk it just yet

Balancing shouldn't be an issue (did that when I reassembled this one) but the TPS is a pain due to the stupid security torx screws. I bought a set of bits to do this but they burnt down in the garage fire before I even used them once. Tried to get them out, but they were inside a plastic case, surrounded by plastic cases that were all in a plastic tool box and everything just melted in to one big lump

[packie]

Balancing shouldn't be an issue (did that when I reassembled this one) but the TPS is a pain due to the stupid security torx screws. I bought a set of bits to do this but they burnt down in the garage fire before I even used them once. Tried to get them out, but they were inside a plastic case, surrounded by plastic cases that were all in a plastic tool box and everything just melted in to one big lump

I think when unfazed said "set the TPS", you have taken it that they might be some setting to do. The TPS mightn't need adjusting at all. So after you adjust your pilots and balance your carbs, turn the bike off and pull out the lead going into the TPS and turn the bike back on. The rev counter should read either 0 rpm, 5000 rpm or 10,000 rpm. If it's at 5000rpm, it is in the correct position and you don't need to adjust it at all and need a torx kit. Even at that, If it does need adjusting then you will still be able to drive it to a small mecahnic who would do that 2 sec adjustment for free or give you a loan of the torx key. But as I said, it might not need adjusting at all so don't let not having the torx kit stop you from doing the rest of the job.

[Dead Eye]

Oh don't worry it won't, it's just a pain to not be able to adjust if necessary haha

Probably going to deal with these issues today if work is quiet

[Dead Eye]

Got out today to adjust the screws, got 3 out of the 4 buggers - that 3rd one really is a pain. However, wanted to make sure I was going in the right direction so went for a ride and I think I can safely say my Fazer has been set from stun to kill :evil :lol

Definitely pulling a lot better but I'm hoping that the MPG shows this as well and its not just a placebo affect