1999 carb jet identification

[Titus]

Hi everyone,


Having problems with my bike...think it's carbs, won't idle unless on choke. Have taken carbs off..can identify main jet and what I think is the pilot jet. But there is another jet, which seems completely blocked, but I can't seem to identify this one in any diagrams. Other than one which called it the 'primary jet'. I have attached a photo which I nabbed from RubyRacing'post as it shows the three jets. The one I am referring to is the one nearest the camera on the right.
Any help gratefully received!
Thanks

[Bretty]

I think the 'blocked' screw doesn't actually have a through hole. I couldn't work out what that screw was for, but my carbs are the same.

How long did you spend trying to unblock it? ;-)

[Titus]

Thanks Bretty. I was coming to the same conclusion! Spent a bit of time trying to blow them through and Still got them sitting in carb cleaner! But your answer is reassuring. Any idea what this closed passage does?


Cheers

[unfazed]

Most likely the carb body is used in other application and that jet is required in those applications.

As for your problem the jet that is most likely blocked is the pilot jet which long smooth one on the left.
There is a star type web within the jet itself, best bet is to use good quality cellulose paint thinners or acetone and soak the jet in it for a few hours and then blow through in reverse to normal flow.
For stubborn stuff I use a bristle from a brass wire brush as this will not damage the brass jet.

[Titus]

Thanks Unfazed. That makes sense. Figured it was the pilot jet..will get soaking.

[Chillitt]

I'm having the same trouble with the same jet... On the Fiche is described as Jet Main 0.6 so I'd have thought there should be a hole there somewhere..  They have been in the carb cleaner for 36 hours and still no joy, they also had a ride in B-I-Ls ultrasound cleaner, but that just seems to have got everything wet...  It's going to break my heart if I have to buy new jets at 6 quid each..

[Html33]

I had an ER5 that i spent ages going bloody going cross-eyed trying to see the light. In the end like above mentioned i use a piece of soft wire and run it through a few times. Refitted to the bike and although the jet had barely any viable light through it worked as expected.

[unfazed]

I'm having the same trouble with the same jet... On the Fiche is described as Jet Main 0.6 so I'd have thought there should be a hole there somewhere..  They have been in the carb cleaner for 36 hours and still no joy, they also had a ride in B-I-Ls ultrasound cleaner, but that just seems to have got everything wet...  It's going to break my heart if I have to buy new jets at 6 quid each..

If they are lacquered up from evaporated petrol, the best thing to shift the lacquer is cellulose thinners or acetone. Carb cleaner in my opinion is not strong enough to soften the lacquer.

[Chillitt]

I'm having the same trouble with the same jet... On the Fiche is described as Jet Main 0.6 so I'd have thought there should be a hole there somewhere..  They have been in the carb cleaner for 36 hours and still no joy, they also had a ride in B-I-Ls ultrasound cleaner, but that just seems to have got everything wet...  It's going to break my heart if I have to buy new jets at 6 quid each..

If they are lacquered up from evaporated petrol, the best thing to shift the lacquer is cellulose thinners or acetone. Carb cleaner in my opinion is not strong enough to soften the lacquer.

I have put them in some vinegar for the night. Hope springs eternal...

[Chillitt]

Just re  read this, to be clear, does the 2nd main jet have a hole in it or not? Its now had an overnight in white vinegar and I cant see any sign of a hole there...

[Bretty]

I'm pretty sure you have a main jet (under the needle), a pilot jet and a blank jet that has the same screw head as the main jet and looks like it has a hole but it doesn't.

Mines the same, nothing passes through the blank jet, put mine all back together and it runs fine.

Brett

[Chillitt]

I'm pretty sure you have a main jet (under the needle), a pilot jet and a blank jet that has the same screw head as the main jet and looks like it has a hole but it doesn't.

Mines the same, nothing passes through the blank jet, put mine all back together and it runs fine.

Brett

Thank you. I'll stop trying to unbung it then.. 

[bikemad]

Sounds like the problems I had mine was running on 3 when I took carbs off that one was blocked,also had one rear inlet on main body that had to be poked out with a wire bristle,upon removing the pilot air screws blowing an airline though there cleared more crap I used brake cleaner spray never thought about thinner to clean jets I'll try to remember that next time.


Another trick I learned whilst apart was to polish the air screws & the brass float seats bit of rag wrapped around screwdriver (careful you don't scratch it) or small punch autosolve etc polish buff couple of times with clean rag hey presto 😎