I finally got back to my yogurt cup tuning. I cut it down so that the large diameter of the yogurt cup was the same as the inside small diameter of the K&N cone. Now it sits on the bottom of the cone snug against the pleats and is about 3" below the opening of the cone. This really didn't make much difference though with the lean popping behavior. Slightly worse than it was with the full size cup, not quite as bad as just the straight K&N. So, since I want the K&N to work, I guess this leaves the carbs. Before checking the jet size, I'm wondering if it would be worth it to try quarter or eighth turn adjustments to these? The PO said they were rebuilt carbs so it's possible those aren't set right, especially since the limiter caps are all removed. My buddy has the tiny carburetor drill bits for checking the jet sizes. I'll see if I can't borrow those off of him.
Pictures of the trimmed cup and mp3 of both the OEM airfilter and the K&N are on my blog. http://munz.kicks-ass.net/nighthawk/?p=295 -Kyle -Sent from Houston, TX, United States On Fri, Sep 4, 2009 at 10:49 PM, Dennis Hammerl <[email protected]> wrote: > That's the largest cup I've seen so far in one of those. !! Mine is about > 2/3 that size and truncated. Now, you have to admit it works. The remaining > issue is still to be addressed. Get a small (stubby) Phillips screw > driver and remove one of the outer float bowls (carbs on bike) and check the > main jet size. Actually check the slow jet size too. The OEM is #115 and > #35. What you are describing is happening during "transition" (from all jets > as a collective to main) As the revs climb above the trouble zone and the > air speed (that's what this is all about, remember?) increases enough to > atomize a lot of fuel, it goes good. I'm not there and have no crystal ball, > this is my best guess at this point. You have increased air speed a ton and > it does run better. Now you have to dig in. Even if the jet sizes are > correct, there is no reason to believe it. That's where sized wires come in. > I can supply you with the the wire sizes (and wires) to check that they have > / have not been reamed to some new size. your bike has been altered which > you cannot deny. Does it go deeper ? Let's see. When you get it right, that > gonzo cup might have to be replaced with a smaller one. From what you say, > you've made great progress with your problem. The last little bit always > takes the most work. You're gonna' get it right. Hang in there. > > Just a note, yogurt cups are for California models. 49 state models use > soft drink cups. > > --- On *Fri, 9/4/09, Kyle Munz <[email protected]>* wrote: > > > From: Kyle Munz <[email protected]> > Subject: [Nighthawk Lovers] K&N filter saga continues. > To: [email protected] > Date: Friday, September 4, 2009, 10:41 PM > > > Ok, Per Dennis' advice I reduced the interior volume of my cone-shaped K&N > filter, and that definitely improved things but it's not quite perfect. > I couldn't locate a dixie cup (when you *need* one they're nowhere around) > so I went with an empty yogurt cup. Sorry, I don't know what flavor. Anyhow, > this took the bike from popping constantly and barely climbing above 4grand > to a bike that will actually start, idle, and rev. > It still is off just a tad. The exhaust sounds a bit more "hollow" that it > did before. Can't describe it better than that. > I've recorded an audio file of the exhaust popping and posted it on my blog > at http://munz.kicks-ass.net/nighthawk/?p=280 for anyone interested. It > starts at 2K, moves up the 3K, then to 4K where it starts to pop a bit, and > then starts to pop alot as I move up to 5K. After 5K it takes off like a > champ and definitely has more power in the higher revs than it did before, > but I want the lower RPM rideability I hear so much about ;) The end of the > audio file is a quick rev up to 8K with no popping, it's just trying to > sustain it between 4 and 5 that is kind of rough. > > So, do I keep tweaking my yogurt cups or is it time to monkey with the > jets? I really don't want to monkey with the jets :) > Also, all test rides were done with the lid and snorkel bolted in place. > > [image: K&N filter with yogurt cup > modifier]<http://munz.kicks-ass.net/nighthawk/?attachment_id=281> > > > -Kyle > -Sent from Houston, TX, United States > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en -~----------~----~----~----~------~----~------~--~---
