richen/lean?

[3 on the Tree]

Which way do you turn the mixture screw to richen or lean out a mixture? Does right (in) richen the mixture and left (out) lean the mixture? I can't remember. Can someone help?

[Meat-BoX]

which screw lol i want to know this
and if the plug is light its? and if its dark its?
I had a wet plug but the tip was white. 32:1 WITH 110 OCTANE

[atctim]

Meat-Box - white = lean - not good for this time of year. Fatten her up a bit.

[200XMichigan]

There are a few carbs that are backwards, turn the screw in makes it richer, turning it out makes it leaner. It depends what side of the slide the mixture screw is on. When I got the Boyesen Power Reeds for my YT175 the rejetting instructions gave me that info.

[ceaserthethird]

My Keihin carbs are - screw in for rich & screw out for lean aka more air :)

We need more details ( 2 stroke or 4 , stock or larger carb ?

[Meat-BoX]

stock mikuni for the tecate 32 mm? I have no clue about Jetting. When you say fatten her up do you mean go more than 32:1 mixture or adjust jetting. I will admit I am totally clueless but it seems my Carb is jammin me up now and preventing me from riding. Im missing the ice racing season. again sux

[200XMichigan]

If you are re-jetting for winter, it means fatten up the jets, so you go up a size, more fuel, large holes in the jet. There is a great article on jetting under the world class help section.

[fabiodriven]

stock mikuni for the tecate 32 mm? I have no clue about Jetting. When you say fatten her up do you mean go more than 32:1 mixture or adjust jetting. I will admit I am totally clueless but it seems my Carb is jammin me up now and preventing me from riding. Im missing the ice racing season. again sux

Stock is 34mm Meat. Check this out- http://www.3wheelerworld.com/showthread.php?125345-Frustrated-and-looking-for-help.

[beets442]

VM round slidehttp://www.mikuni.com/pdf/vmmanual.pdf

[Meat-BoX]

Going to Bristol Racing Sat. morning and Rich the owner is going to set me up right with the jetting. They were the original speed shop for ATV's here in C.N.Y. AND HAD A RICH HISTORY OF RACING 3 WHEELERS BACK IN THE DAY. He told me about the Tecates he used to race and I hope to chat him up about that, some possible porting in the future and maybe see if he has any 3 wheeler parts around or knows someone who may. I think when he sees my Tecate he will get all excited and let loose some good knowledge. But best of all hes got the jets and is going to help me dial her in and teach me about it all. I hope this is the final step to finally having some fun on this Tecate of mine.

[3 on the Tree]

When I turn the screw out, the idle rises. When I turn it it, the idle decreases. I know this is normal, but what is a good way to set your mixture? I have it close to how many turns out it was when I started (I counted how many turns out from fully in before disassembly), but who'se to say if how it was set before was correct.

[Yamaha_Rules69]

If the mixture screw is on the airbox side of the carb, it is an AIR SCREW, and if it is on the side closest to the engine, it is a FUEL SCREW. The adjustment is opposite for each, --------- for airscrew - turn in to make richer, and out for leaner. For fuel screw, in for leaner, and out for richer.
Turn the screw out until you notice a hesitation, take note, then turn it in until hesitation, and take note of that. Now set the screw back out half the number of turns you recorded so it is right in between, and you are set. I would recommend making like 1/4 or 1/2 turn at a time.

[3 on the Tree]

This is the fuel screw that I am describing then. It is on the bottom of the carb right next to the bowl on the side closest to the motor. Do you calibrate the air screw in synch with the fuel screw?

[beets442]

Get your fuel at a decent idle. Start with the air screw mostly in. Back the airscrew out til the idle goes up as high as it can go then turn back in 1/4-1/2 turn. It should be idleing just a hair high so turn the idle back down a hair. SET!

[RubberSalt]

Carbs only have an air screw or a fuel screw, not both. Both due have an idle screw. 2 strokes = air screw, 4 strokes =fuel screw. On the fuel screw(as on the carb), turning it out will give it more gas, the fuel and idle screw effect it until about 1/4 throttle. After that, the needle takes over from 1/4-3/4 throttle. Then your main jet size kicks in from about 3/4-wot

Note that the main jet starts changeing things as far as 1/4 throttle, but at 3/4 it makes a huge difference.
The needle effects it WOT, but doesn't change much after 3/4
The air/fuel screw effects from idle to almost 1/2, but doesn't change much after 1/4


I'd recommend, in general on a 4 stroke carb, turning the fuel screw 3/4turns out and chaning the clip position of the needle to the lowest spot on the needle or getting a larger main jet. Thats a change from stock settings. After that - go read up on jetting and carbs, they are alot simpler than they look once you start understanding them.

What trike is this for?

[3 on the Tree]

It's not a trike, it's the XL250 in my sig. You are right, I looked today and there is only a fuel adjustment screw and nothing else as far as mixture adjustment.

[RubberSalt]

I've actualy got an 1978 xl250s my self - like all my toys - it needs a TON of work, fun bike though!