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Old July 19th, 2022, 12:31 AM   #1
amockalypsenow newbie
Name: Amock
Location: Berkeley
Join Date: Jul 2022

Motorcycle(s): 2010 Blue 250R

Posts: 8
Talking Dr. Strangecarb or: How I Learned to Stop Worrying and Love the Bike (w/pedals)

I now know why Elvis shot the Pantera- I would have shot my ninja earlier today if I had been so equipped!

Backstory... I study Mechanical Engineering at Berkeley, so absolutely nobody would expect me to know how to wrench a darn... I'm just a thumbsucking numbers nerd with not an ounce of common sense... it wouldn't be surprising to anybody that this geek is having a hard time getting a motorcycle to run... But alas, while I am a noob in many ways, I can't claim total ignorance; in a past life I worked at a motorcycle repair shop, as a machinist, fabricator, and welder... and I am most certainly not naive to wrenching on bikes old and new. I should know better and not need to humbly ask for guidance as I am about to do.

I bow my head and ask for help and guidance from ye wizened ninjette senseis:

The facts:
  • Sea level, low 70s.
  • 2010 with ~15k miles.
  • Well looked after generally speaking
  • Bought by a neighbor lady a few years ago then left out to pasture in the open air for a couple years
  • Apparently it ran fine when last parked (grain of salt taken here)
  • Sold to me "as is" covered in spider webs and grime.
  • I cleaned it up, bought a new battery, and pulled the carbs
  • I removed the charcoal canisters and left the tank vents unblocked
  • I removed a gps tracker of some kind that was wired into the bike and stuck to the charcoal canister with double sided tape
  • I made an exhaust recirculation block off plate ala ssr (the exhaust valve thingy was not part of the wiring loom, so I didn't need to make a resistor bypass as other years do to completely cancel and remove this()
  • I removed the plugs over the air/fuel screws- checked if they were screwed out to spec
  • Carbs both had a 98 main and a 38 pilot
  • I simplified the carb vacuum system to go directly to the petcock
  • Upon dropping the bowls, I was surprised to find that the carbs were actually not the gummy nightmare I had been expecting them to be. Still I pulled the main and pilot jets and blasted carb cleaner through them, and also the air jets and other passages. (I attribute this to the vacuum operated petcock)
  • I drained the fuel tank and filled it with 1 gallon of premium dinosaur juice
  • I checked to make sure the petcock was flowing said dino juice
  • And then things got disappointing...

Choke to on position, I hit the starter, and no combustion bang bang happy sounds were produced. Sad but is it ever this easy? I next sprayed carb cleaner (AKA "start ya bastard!!"... aka SYB) in the airbox, hit the magic button, and it started to turn over feebly (to be expected from a 250 parallel twin) and then it died. I sprayed in more SYB, and then started it up again. By intermittently spraying her with SYB, I got her to warm up and meekly idle with the choke on. The top end sounded adequately healthy. I played (perhaps foolishly) with the idle speed adjuster a bit. Given that the idle was only a faint thing, I considered that it might not be firing on all cylinders (2) so I unplugged the coil on either side and determined both cylinders were firing. I checked to make sure the sparkplug boots were securely attached to the plugs, and had a brief look at the plugs, which looked clean and rust free. The bike runs the same with the petcock to prime or on.

When I removed the choke, it would die, so I figured the pilot jets had gotten re-gummed up, so I pulled the carbs and cleaned them again, noting that they were not apparently blocked in the slightest way. Upon reassembly, the bike acted the exact same way.

I am running out of ideas now, and moreover I am taking three classes this summer and ran out of time quite early on in this project. I do however want to get this bike running so I can visit my sweet heart without having to spend either 3 hours on public transportation or $80 in rideshare fees each way. Obviously the sensible thing to do would be to find a sidesweetie who lives closer or something like that but I'm a fool in love so I must make the trip to see my dearest (and she comes to see me as much or more).

So, friendly sage ninjette wizards, what should I do next to get this bike running like a top? In the meantime, I'll be pedaling my pushbike around...

Pics show the bike post light-cleaning and pre-cannisterectomy.


Last futzed with by amockalypsenow; July 19th, 2022 at 11:45 PM.
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Old July 19th, 2022, 10:25 PM   #2
DannoXYZ certified postwhore
Name: AKA JacRyann
Location: Mesa, AZ
Join Date: Dec 2011

Motorcycle(s): CB125T EX250F-street Ninja250R-race CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR VFR750F

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MOTY - 2018, MOTM - Nov '17
Take solace in knowning that you're amongst millions and millions of new Ninja 250 owners who've gone through this. I went through this exact problem when I got my 1st 250 years ago.

Bottom-line? Carbs aren't factory-fresh clean! Bike ran perfectly fine when it left showroom floor and will again when they get cleaned to factory-fresh clean. Many, many expert mechanics have had to pull their carbs 4-5x for ever deeper cleaning before they got them factory-fresh clean. One guy had to pull his carbs 10x !!!

Note, "carb cleaner" sprays no longer work due to removal of chlorinated compounds. Don't even bother with using them... Maybe just flush chads and remnants from real cleaning... which is.... scrubbing!

1. disassemble down to every last nut, bolt and individual component. If you can take it apart further, keep on going until it's completely separated.

2. Poke out all bleed holes in jets, pilot-screw, emulsion tube, and carb-venturi with soft copper wire.

3. scrub out all hidden secret passages in carb-body with brushes and PEA-based fuel-system cleaner. Spray carb "cleaners" no longer work due to removal of chlorinated compounds. Might as well use pee since at least it has some ammonia.

4. ultrasonic soak everything overnight

5. micro soda-blast everything to clear out chads and scruff from above steps

6. replace all rubbers: pilot-screw O-ring, fuel-rail O-ring, float-valves, float-bowl seals

7. set float-level and wet-test

8. sync carbs

On some carbs, even all this isn't good enough. I send to Gordon @ (ducatiman) and they come back running like brand new!

Last futzed with by DannoXYZ; July 20th, 2022 at 12:45 AM.
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Old July 20th, 2022, 04:12 AM   #3
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Location: new york
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Motorcycle(s): '95 DUCATI 900SS/SP '07 DUCATI SS800 '19 HONDA CBR650R

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MOTM - Nov '18, Mar '17
ty for good words @DannoXYZ

OP posted....."2010 with ~15k miles"

have valve clearances ever been checked? Suggest working from the inside out/first things first.
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Old July 20th, 2022, 04:39 AM   #4
amockalypsenow newbie
Name: Amock
Location: Berkeley
Join Date: Jul 2022

Motorcycle(s): 2010 Blue 250R

Posts: 8
Thanks for your messages guys.
Sounds like these carbs are really easy to gum up. I’m trying to find somebody near Berkeley who will let me dunk them in their ultrasonic cleaner. It seems wasteful to buy a cleaner for just one job.
I was also thinking of checking and adjusting the valves as necessary.
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