Carbs... Pilot Air Screw Settings????

[Flatch69]

I have been trying to get my Tiger back on the road after 7 years. In the summer I stripped the carbs to try and make the bike run properly as it would only idle. I cleaned out all the gummed up petrol deposits but when I put the carbs back on the bike will not start at all.

I have just read an article about the function of the pilot air screw on a carb. During the carb clean in the summer I removed this screw (little brass screw/jet in the mouth of the carb on the air box side) from each carb and blew out the passages with carb cleaner nad comporessed air. When I refitted them I screwd them in all the way.

Have I starved the pilot system of air by screwing them in all the way??

Does anyone know if there is a correct setting position???

My haynes manual makes no reference to these screws.

Thank you.

[rf9rider]

If they are Mikunis, you should turn the screws out 1 1/2 to 2 turns out from seated.

Have a look here http://tigertriple.com/forum/viewtopic. ... 2458#52458

[Flatch69]

Thanks for the qiuck reply.

This is the information I followed. I think I know what I have done wrong now.

When I rebuilt the carbs I thought the pilot screw was screw No.12 in the diagram at the bottom of the link you attached. It was these screws that I set at 1 1/2 turns to 2 turns out from seated not the pilot air screw/jets in the mouth of the carb.


So just to confirm the pilot air screw/jets in the mouth of the airbox side of the carb needs to be 1 1/2 turns to 2 turns out from seated.

What is the recomended setting for the pilot screw shown as No.12 in the diagram at the bottom of the link you attached? It was these screws that I set at 1 1/2 turns to 2 turns out from seated.

[nightrunner]

Mustang will be along soon to answer this.  I have the '98 with Keihin carbs.  I think you have a 95-97(?)   But I think the Miks are set the same at 2.5 to 2.75 turns out stock.  Note that after 3 turns you are wasting thread.  Here's a nice tutorial on carbs:

 http://hondanighthawks.net/carb14.htm

Also note the Miks have tiny O-rings on those screws which can get lost.  Or so I read.  I have never had the Miks apart.  

These bikes are notoriously lean from the factory.  You might want to consider rejetting.  Is covered here in many threads

[Flatch69]

I cant get this bike to start even i following the air screw settings posted on this thread.

I have tried to post a picture to show the screws I am adjusting. The screws are in teh hole just off the centre line of the carb.

I have spent hours on the web I acn not find a thread or web site that even mentions adjusting these screws. I think i have the wrong end of the wrong stick.

When it comes to adjustment the only things I can adjust are:-

1, float hieght.
2, Pilot screw located on underside, center on engine side of carb.


I am going to strip them again and see what happens.

[Mustang]

what screws are you talking about in the pic ? there are no screws to adjust on the air box side of the carb

there are only the little screws(pilot needles) on the engine side they should have an rubber oring a flat washer and a spring on them in that order inside the carb body , if you are missing the orings good luck getting it to run .



1 1/2 to 2 turns works well on the mikuni carbs pilots
but they are really supposed to be set using an O2 meter to get the reading at 1% for US bikes and 3% for the rest of the world

Do you have an O2 meter to screw into the bungs on the exhausts ?................if not go with 1 3/4 turn and call it good .

[BruKen]

Those aren't jets mate. Those are the portings to ply positive pressure to the emusifiers. Not trying to be misery guts here but if you fubar those up you are in shitcreek. Clean them and leave them alone.

[Flatch69]

Thanks BruKen & Mustang.

I will strip, clean and reassemble them next week end.

[nightrunner]

Mustang I think you mean CO level in the exhaust, not O2.

[dave NL]

Nope, Mustang means O2

[Mustang]

Mustang I think you mean CO level in the exhaust, not O2.

:oops: I fooked up .........yep CO at 3% @ 1000 RPM is the magic formula .............interesting to note that the official triumph bible says to set the screws at 2 turns for #1 &3 and 2 1/4 turns for #2 (with mikunis ) in the spec section but in the carb section says to set it with the meter at 1% for USA and 2.5 -4.5 % for the rest of the world .

[dave NL]

Hmm ok,

Im used to tuning A/F with a wide band O2 sensor, then again this is on injected engines, but  can be used on carbed engines too. Just stick it in the exhaust.

[Mustang]

dave
pretty muchdifferent methods to achieve the same thing
except the Triumph way is measuring carbon Monoxide in the exhaust emissions
and an O2 measurement is checking the oxygen level in the exhaust emissions

[dave NL]

True that!

when I go for APK (MOT) with my car they also measure the Co levels, if the level is to high (which it usually isnt) I can adjust my air signal to lower emissions. I can permanently read out the A/F ratio inside the car with a AEM wideband O2 sensor to see whats happening and don`t lean out! But I never had to deal with this yet, always passed.

[rybes]

Hmm ok,

Im used to tuning A/F with a wide band O2 sensor, then again this is on injected engines, but  can be used on carbed engines too. Just stick it in the exhaust.

whered ya get one ? whats it called ?  and can i have one now ?

oh and where would i fit it, on the balance pipe ?