how to set Pilot Jet

[Brett unsupervised]

new to me bike missing pilot jet. have new one, clymer does not say how to adjust one unless you removed it and know now many turns it was from seated.

tried search on the forum but failed to find answer (probably error between keyboard and chair)

can someone tell me how to re-install and adjust a pilot Jet?

humbly appreciative,

Brett

 

[MaxMidnight]

Can you confirm what it is you are referring to?
There are two pilot air jets (normally referred to as PAJ1, #90 & PAJ2, #170) and a pilot air screw (located under a tamper proof plug).

If the former they screw in and the latter set to 2 1/2 turns out as a starting point.

 

[Brett unsupervised]

MM -- thanks -- the one I am referring to is the one in the image below (I assume that is the tamper proof plug). Plug looks like a brass fitting with a tiny hole in the middle. the hole that plug should be in is completely open (nothing in it) on the front right carb. I ordered a new one and the cap.

Pilot screw set: 12R-14105-00-00
Cap: 3F9-14118-00-00

you say 2.5 turns out "as a starting point". how do I adjust it to the "final point".

If I want to check the other 3 -- any secret to getting the tamper proof cap off? Or should I leave the others alone? try to run a small wire through the small hole to see if plugged?

 

[MaxMidnight]

The idle mixture screws are set at the factory so if it is idling OK then I'd be inclined to leave them.
To get them out, drill through with a small drill then screw in a self tapping screw and pull. N very B! The idle mixture screw isn't that far away from the base of the plug so wrap some tape around the bottom of the drill, leaving a few millimetres of the cutting helix uncovered. Go gently and stop as soon as you drill through.
To set them properly you would need to use a CO meter tapped into the relevant header...no I haven't got one either.
You can tweak it a little by listening to the engine note and the idle.
I doubt in the grand scheme of things it make much difference that you will notice, others can chime in with their preferred method.

 

[Brett unsupervised]

The idle mixture screws are set at the factory so if it is idling OK then I'd be inclined to leave them.
To get them out, drill through with a small drill then screw in a self tapping screw and pull. N very B! The idle mixture screw isn't that far away from the base of the plug so wrap some tape around the bottom of the drill, leaving a few millimetres of the cutting helix uncovered. Go gently and stop as soon as you drill through.
To set them properly you would need to use a CO meter tapped into the relevant header...no I haven't got one either.
You can tweak it a little by listening to the engine note and the idle.
I doubt in the grand scheme of things it make much difference that you will notice, others can chime in with their preferred method.

thank you

 

[99YAMAHAVMAX]

thank you

Start at 2 1/2 turn out from seated.

 

[dannymax]

Start at 2 1/2 turns...turn it in till the engine falters, back it out till the engine falters and go halfway between the two. Sounds easy...it isn't.

 

[Mass 2112]

This may be wrong and i am sure i will be corrected but i check my exhaust. If there is a oil feel to some black sut they are letting to much gas, turn 1/8 turns in till you get a nice clean exhaust and dry you got the [ g ] spot. that is just how i do it. beats pulling plugs to look at.

 

[MaxMidnight]

Not saying you are wrong but in my experience the soot of a rich engine is usually dry?

 

[Mass 2112]

Hey I had a 50/50 chance. Thanks now I can get my air/fuel mixture in the ball park.