new xr150l

[irk_miller]

So is the nibbi a copy of Keihin carb?

It's more a copy of the early SL10A or 660a Keihin, though NIBBI calls it a PE.  The SL10A and 660a that came on early XRs and even back on small cc SLs and CBs had the oval bore.

[m in sc]

yes. its def got some 'pwk' features though. I'll be honest, the machining and build quality is excellent.

[Djg8493]

I agree that believe it or not the Nibbi carbs actually work very well and the quality is much better than you would expect for a $50 carb.  I've been running them on pitbikes and they fun much better than the fake Mikunis

[m in sc]

been up to no good.

now at 200CC and dialing in the carb. this is an ebay BBK w cam for a CRF150. was under 100 bucks shipped.. suspiciously cheap but... fuckit. it does work well.





tapped and plugged that ridiculous air injection valve passage in the head



few week later (yesterday) added a wideband to dial int he carb. It ran well but didn't seem.. all there. was dead rich wot, and found a lean spot at pilot to needle transition.  seems better, pretty much dialed in after a few runs last night.







 


why? the idea is to make more power down low and midrange so i can gear it less aggressively and not wind it out near as much at 60 mph, 65, whatever. even dialed in wrong, it did that since i changed the sprockets after the BBK... this should just tweak it where it is the most happy.  and the low end was much improved.