Carb Cleaning tip!

[Briang]

This was amazing.
Recently a friend bought and loaned me a carb cleaning book called Larry's Carb Cleaning Book.
It is specifically for the Keihin Carbs typical to Hondas of all stripes. Last year I had bought Randakks carb kit and followed the book that came with it to the letter and it worked out pretty well. The thing ran good, mostly, but had a bit of a flat spot mid range in the rpms, sometimes hesitated on hard throttle from lower ranges, stuff like that. It always ran better when it was hot.

Larry has taken carburetors and cut them apart to reveal the passages and ports. Its quite fascinating to see the pathways within. It really helps with the understanding of whats going on. He's got lots of good advise and perspectives.

Now, here is what really made this effective, in my mind. He says to take the brass jets and pass jeweler sized drill bits through the tiny drillings, which pass sideways in the tubes. This is to clear the build up of tarnish and deposits which don't really get removed in the chemical or ultrasonic cleanings. A welder friend offer to me his tip cleaning tool, a set of thin serrated wire cleaners, one of which was the perfect size to pass through my jets. I could feel the thing be slightly tight at the start and with a minor bit of pressure begin to pass freely back and forth. I made certain not to be aggressive with them and I was not removing metal, just the build up of tarnish and such. With such narrow ports the buildup of really small amounts of crud can reduce the effective size of the passages by a significant percentage even though you can see through them.

Today I rode the bike after setting the idle jets and syncing the carbs. Frankly, it was amazing, the difference. No flat spots, snapped right up through all the range from lugging to rocketing along; from decelerating down hill and then immediately powering up to speed again unhesitatingly. Its getting the full requirement of fuel into the venturi and into the cylinders like it did when it was new.

If you are into doing your own carb work, and who isn't, I recommend getting a copy of Larry's book.

[kenai]

Hi- i have the same midrange flat spot ; makes sense what your saying that if the ultrasonic cleaner is not getting the residues out ... the passage is smaller...I'll try it thxs kenai

[RB]

I poke a pin/needle through those holes and run it back and forth a bit..any stiff wire of the right size works.

[Briang]

This is the tool I used. I got one from Princess Auto in Canada but I have no doubt that Harbor Frieght would have one too. About 7$. The wires are serrated which I think are more effective than a smooth wire for actually scrubbing off the tarnish.

I can report that my bike feels like new again. The flat spot is gone, cold starting is smooth and acceleration after deceleration is seamless.

[jdvorchak]

I use roughly the same tool on all of my carbs. Welding tip cleaner, about $3 at most welding supply shops or online. Caution there is not one of those wires that will go through the center of an idle jet and don't try to force it. For that hole I often use a #10 Guitar string, to get the hole open initially, then squirt carb/brake fluid through it until I get a nice stream.

http://www.ebay.com/itm/13-Welding-Tip- ... xydyxSQgwJ


I do have a set of numbered drill bits, sometimes call jewelry bits, and a pin vise. But I'm not a fan of using them on idle jets. They work great for cleaning the spooge hole on a brake M/C. #79 or #80.

http://www.ebay.com/itm/21pc-Mini-Drill ... Swl9BWMSPL

Every shop should have these two items.

These will get the jets clean but most new timers forget about the passages above the jets. Make sure that you can squirt carb/brake cleaner all the way through the carb. The idle passages will exit right at the butterfly. If it doesn't, boil or clean them until it does.

Most first timers will also be afraid of completely dismantling a carb. The result is a carb that is not clean enough. the enrichener circuit is often over looked as well. It too has to be clean.

[Briang]

I have incorporated a water pik to chase out the channels and passageways as a flow of water is quite visible. It becomes nessecary to plug as many fuel holes as possible to differentiate the air passageways associated with them.