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Old November 24th, 2018, 12:47 PM   #4
Karman
ninjette.org member
 
Name: Karman
Location: New haven
Join Date: Nov 2018

Motorcycle(s): 2010 Ninja 250r Red

Posts: 23
Quote:
Originally Posted by DannoXYZ View Post
Newgen (2008-2012) bike is already super-rich from factory. Here's what I have on my race bike:

- Tyga full-exhaust, no cat, Tyga free-flow muffler
- K&N filter
- snorkel removed

All this produces +20% more air-flow than stock and generates +20% more power and guess what? It's still rich. Dyno-testing with Spears Racing (sponsor) gave best results with going to smaller main-jets than factory. Down from factory 98 to 96, even 94 in summer.


If you read people's reports over time, you'll find that they get stumbling and mis-behaving. So they put bigger jets into their carbs and the problem is fixed right? But couple years later, they get stumbling again and put even larger and larger jets in to fix. Problem here isn't that carbs are setup lean originally and gets leaner and leaner over time. It's because their carb's fuel-circuits are getting clogged with dried fuel! The solution is to completely disassemble the cars, clean out all jets with wire, soak with real cleaners that'll take skin off nuclear subs, dunk in ultrasonic cleaner for days, soda-blast all fuel-circuits to clean and clear.

The issue isn't that carbs are lean, as implied by solution of bigger jets. That's just monkeying around with symptoms of real problem. That carbs aren't factory-clean. They ran perfectly when leaving the factory, and they should run perfectly fine with factory configuration when things are factory-fresh clean. I've had carbs on my pre-gen and new-gen 250s refurbished to factory-fresh clean condition by ducatiman and they run perfectly fine in stock configuration. I've even downsized jets on all of them to improve power and performance.
Wow, if that’s true seems 95% of people are misinformed since so many people rave about the needle shimming.
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