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Pilot Jets Dry as a Bone. What am I missing?

Jahred

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So I disassembled carbs on 82 CB750 that idled only on choke and killed with throttle.

I'm sure I did not do the process justice. They looked pretty clean. Removed all the jets ... they all looked clean. Stuffed the wire brushed through each including the pilot jets, at least the various holes on the underlying jet. The main hole pilot jet hole was too small for the carb set of brushes/files I had (amazon) but the hole was visible.

Inspected pilot jet operation while running and with throttle there is virtually nothing squirting out of any of the pilot jets.

Is there an issue with the accelerator pump? Are the jets not clean just because I can see opening though the entire jet?

Any thoughts?

I'm also getting a bit of white smoke once at temp out of cylinder 4. Somebody tell me that is something other than internal ring or valve. :-(
 
'Are the jets not clean just because I can see opening though the entire jet?'

You cannot see far enough up that jet to even think of verifying it open by sight alone. The hole is only 13 thousandths in diameter. If they use ethanol in your local fuel then the top of that hole dries up first as it is most exposed to air, it then clogs from the top down. That top of hole is the smallest too and why it holds onto a small bit of fuel to then dry it to clog. Ethanol fuel clogs like a plastic when it reduces due to evaporation.

Any white smoke is more common to be valve seals, which wear out pretty fast. The valve guides do not really wear and the rings not bad either unless engine has been abused by not changing the oil.
 
AMC, thanks. I know that hole is minute ... I can't get any standard carb tools/cleaning rods down it .. but I can see the hole in each ... I think you are telling me that irrespective of being able to see through the jet and the diffuser holes the internals may still be blocked ... in looking at the treatise you were kind enough to send me I see that what I am really trying to figure out is I have no gas emanating from the what I guess is technically the accelerator pump nozzles ... can't see openings as they face inward ... and it looks like to clean those ... (this would appear to be why I get no low end gas and engine kills with throttle) ... you need to separate the carbs ... I guess that or a long chem bath in a supersized bucket. So at the end of the day i could still have blockage in pilot jet, or in accelerator pump nozzles themselves ... or related feeds ...
 
You use a piece of 'E' string guitar wire, the smallest diameter there is on one. Perfect for the pilot hole size.

The Euro models of DOHC are exactly the same as the US ones but do NOT have any accelerator pump at all, give that some thought. The only difference is the idle mixture screws are unscrewed out a bit more to richen the idle.

You have to remove #2 fuel bowl to get to the accelerator pump check valve pressed into the passage there, it is a one way check valve and must work or zero pump output.

Chemical bath with carbs still together will wreck the air cut diaphragms, they will not survive that. Provided you are still using them.
 
AMC, thanks. Big hint on carb number 2! And yes, I knew after sending the big bucket idea was death. ��
 
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