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quick question for someone familiar w the internals of a 1991 cb750 carburator

Jayboy74

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Hello Everyone , Finnally got around to removing my carbs from my bike , It was only running on the 2 left cylinders and was gettin good spark so i figured i would clean the carbs.

Here is the question

I think that one of the brass jets should have a hole all the way through it but it does not. If your looking at the inside of the carb tere are 3 protrusions , one is the main jet , the 2nd is a jet and the 3rd is jus a hole wth nothing removable . The middle smaller jet looks like it should be drilled all the way through but its not, It has a hole on the top where you use the straight head screw driver to remove it and it also has a hole on the bottom with several small holesin the sides of it. Should this be clear all the way through or not? I was using various wires ,needles etc but nothing will go through it.

My carbs were totally gunked up , You could noteven see some of the holes in the jet from so much junk.

take care
Justin
 
That's your slow jet, and being clogged explains why you aren't running on those cylinders.

The reason you can't get anything through is because the orifice is tiny, and in fact you can do a lot of damage by forcing something through it. You can spend hours trying to clear them but you're better off getting new ones.

If your jets are that gunked up it's likely that the internal passages are clogged as well, including the air/fuel mixture (aka pilot) needle circuit. The only way to do it right is to have them apart to the last tiny bit and go through them one passage at a time.

Otherwise you can fall into a cycle of doing them over and over and never find the cause.

OSC
http://www.oldschoolcarbs.com
"Education is everything. A cauliflower is a cabbage with a college education." Mark Twain
 
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