View Single Post
Old April 27th, 2020, 11:06 AM   #11
DannoXYZ certified postwhore
Name: AKA JacRyann
Location: SF East Bay
Join Date: Dec 2011

Motorcycle(s): CB125T, Ninja250R racer,Ninja250R street EX250F#1 EX250F#2 EX250E CBR250R(MC19) CBR250RR(MC22) VF500F CBR600RR

Posts: A lot.
MOTY - 2018, MOTM - Nov '17
Originally Posted by ATLANTA View Post
That makes a lot of sense. Do you think you could give me a little more detail as to the process? I really want to give this a try
Hi Jonathan, welcome to Ninjette!

All info you need to know can be found in search for "clean carbs ducatiman". Note, due to regulatory changes, modern spray "carb cleaners" no longer work. They don't have chlorinated compounds such as trichloroethylene, carbon-tetrachloride, or chlorobenzene, which does actual job of cutting polyvinyl bonds in dried petrol. Nowadays, spray "carb cleaner" is just weak carrier solvents that does nothing. I used to clean off inside of sprocket covers with carb-cleaner, and it would drip out as tar-like sludge goo. Now, it drips off clear-grey having dissolved nothing.

Thorough cleaning process requires lots of manual scrubbing. i'll give you summary here. Process roughly goes like this:

1. Scrub out all hidden secret fuel-circuits beyond jets with brushes. Amazon - nylon brushes. I like to use 75/25% acetone mix with PEA-based fuel-system cleaner such as Chevron Techron, Red Line SI-1, etc.

2. Soak in ultrasonic cleaner for hours using polar solvent (PineSol, Totally Awesome, vinegar, etc.) Be aware that Simple Green dissolves aluminium, so avoid it. Amazon - 4L Ultrasonic cleaner

3. Scrub again with brushes. Pay particular attention to holes where fuel-circuits exit into carb-venturi (neon green dots in photos below). Remove deposits but be careful not to remove any metal as size of these holes are critical to fuel-metering

4. micro soda-blast all circuits to clean out debris. Use finest soda available AircraftSpruce - mini soda blaster

5. replace all rubber parts: float-valves, O-rings and seals

6. adjust float-levels

7. sync carbs with manometers. While old-style analogue gauges work, I prefer modern digital versions. carb-sync gauges

Be sure to completely disassemble emulsion tube and poke out all lateral bleed holes with copper wire . Same with pilot jets.

Originally Posted by n4mwd View Post
Here are the secret passages in the carbs. They are kind of hard to figure out sometimes and this picture guide will show where they are for cleaning purposes.

Carb Pilot jet Circuit

Carb Main Jet Circuit

Carb Fuel and Overflow Drain

Carb Diaphragm Intake, upper choke and vacuum ports

Carb Choke Circuit

All of this takes a lot of time and certain amount of experience. It takes me longer to do complete carb-cleaning job than it would take for complete engine tear-down and rebuild. Here's engine I rebuilt in less than one weekend, versus over a week for carb-cleaning. I prefer to just send them to ducatiman for refurb and restoration as he's all required equipment and is so much more experienced and efficient at it.

Last futzed with by DannoXYZ; June 7th, 2020 at 05:33 PM.
DannoXYZ is offline   Reply With Quote