Pilot jet for 79

[Gallaecus]

How can you tell if the pilot jets should be plugged or not ? these have screws plugging them and under that are pilot jets down lower. I have seen rubber plugs, but someone obviously put screws in there.

[GLoweVA]

The pilot jets should be plugged only if there's a 'crossover' hole from the main jet into the pilot jet. These were for the later style carbs (80-81) The only way to be 100% sure is to pull the jet(s) and look down the hole.
Now, I've noticed that they have brass floats, which indicate that those are probably early carbs and your post says for 79 so, there's probably not a crossover hole, so I would think that the pilot hole shouldn't be plugged.

[DAVINCI]

Keep the plug. No, someone didn't just 'put screws in there', the carb was designed for the screw plug and threaded to accept it. i believe george has his facts reversed.

[GLoweVA]

I could have my facts reversed. I don't own an early XS and each of my 80's are different. (one with the crossover and one with out) So, my G has plugs and my SG does not.

Sorry, just trying to help.

[Gallaecus]

so if i take out the main jet and probably the emulsion tube, I would see a hole toward the pilot jet ??? if there is a hole, then safe to say the pilots should be plugged? thanks for your help. going to put em back on plugged and fire it up.

[Gallaecus]

120 psi on 2

all cylinders firing although doesn't idle without choke on. would this indicate I need to unplug the pilot jets?

1,3,4 have 170 psi #2 has 120. is that too far out for a valve adjustment ? smokes pretty good out the left side. i will try a compression check with some oil in cylinder to see if it is the rings as well.

looks like #4 spits a tiny amount of gas out the back of carb while running, probably intake valve not sealing ?

any thoughts appreciated.

[ddragon63]

my 79 have pilot jets... and if it wont idle without choke that usually the first indication of a plugged up pilot jet. YMMV but every bike I've ever owned that wouldn't idle once you dropped the choke off it was due to a clogged pilot.

[trdriver71]

How can you tell if the pilot jets should be plugged or not ? these have screws plugging them and under that are pilot jets down lower. I have seen rubber plugs, but someone obviously put screws in there.

Those are the same carbs I have on my bike and those screws need to be there also there should be an aluminum washer there too make sure that you put it back on there too. also +1 on the plugged pilot jet.

[mack]

When you say it won't idle

the choke out do you mean on initial start up or after it is warmed up. My 79 doesn't idle either w.o the choke on during warm up but after it's warm it idles like a contented cat with no choke at all.

[mack]

Sorry if

missed something. Your signature show's you have an 81 LH, are these carbs for a different bike? Your LH carbs will look much different inside the bowl. The config I see is for 78/79 carbs not 81's.

[Gallaecus]

Quote...
"missed something. Your signature show's you have an 81 LH, are these carbs for a different bike? Your LH carbs will look much different inside the bowl. The config I see is for 78/79 carbs not 81's. "

thanks for the reply Mack. I need to update my signature. I do have an 81 MNS your bikes look really good btw. the carb pic is from a 79 it wont idle without the choke warm or cold. probably clogged pilot jets,

Quote...
"Those are the same carbs I have on my bike and those screws need to be there also there should be an aluminum washer there too make sure that you put it back on there too. also +1 on the plugged pilot jet."

thanks for the reply trdriver71. good to hear someone else has screws in there. I have heard of rubber plugs but not seen the screws before, and they do have the washers. thx

[natemoen]

Screws are on the '78-'79's, some '80's have the rubber plug, rest of the '80's and the '81's have nothing over them.

[mikubuilder]

yeah, I have a screw also, and if you take the emulsion tube out, you will see the crossover...take care when taking pilots out...they sit down there pretty good, so a good fitting screw driver is a must...soak it overnight if you feel that they're stuck...I partially stripped two of them, but got lucky and got them out without drilling

[mack]

cross over

may as well clean everything once your in there. If the pilots are plugged you probably have to address the emulsion tubes as well and the carb bowl passages. Don't forget to make sure the cross overs are clear and clean as well. What bike you putting these in?