Unblocking passageways

[Afterdarkmark]

I've asked myself the same question, but don't have a definitive answer. It resembled dried dirt or sand.

The obvious guess is debris from dirty fuel that built up over time, but for whatever reason it didn't affect the other three carbs. My best WAG is that carb #1 is lower than the other three when the bike is at rest on the side stand.

[tatu]

Thanks for the response. If you have any of that detritus remaining it would be interesting to drip some vinegar or phosphoric just to see what fizzes it away. Just one more question, out of the three? passages you opened was any one worse or more blocked than the others?

[Afterdarkmark]

All went in the trash, sorry.

The vertical passage seemed to be the worst. I got most of it out by running a drill bit down through the hole in the diaphragm chamber on the top of the carb, but I still had to run the the drill in through the other two holes to fully clear the blockage.

[metalfab]

Nice fix, sometimes not giving up and going the extra mile is what it takes for odd problems.

[metalfab]

What is this crud made of?
I have tried solvents and it doesn't touch it even cleaning solutions in the ultrasonic won't budge it. I've tried getting Berryman's that is so widely recommended here but it isn't available in UK.
I suspect that it has to be an acid solution, vinegar or phosphoric.
I had read years ago that someone had done exactly the process described here on some honda carbs but had used some lead shot to reseal the drilled out orifices.
Thanks Mark for sharing this with us. I think this should be added to the stickies of the various help pages.

Berrymans is made just outside Dallas Texas and isnt widely available outside the US. The professional formula called 0906 is about 40% methylene chloride, 10% xylene, 10% cresylic acid. Besides that it has chemicals to slow evaporation and the rest is water. If you can get the chemicals you can make it.