Gen 2 airbox lid report

[mik_str]

Time to try Gen 2 (below) has arrived.....


OK, I was looking at having to pull the carbs to fine-tune jetting for Gen 1 (pilot circuit was a bit too rich, as were needles; bike emitted puffs of black smoke when punching it hard) so I cheated and thought I'd give Gen 2 a try So, idle is smoother than it has even been (tended to wander a bit with Gen 1), I mean very smooth. I had to richen up the fuel screws ever so lightly (half-turn from the leanest setting I tried with Gen 1, which still felt too rich with it; it had a mild hesitation when rolling on it from very low revs and the half-turn richer seems to have cleaned it up). It still smoked a bit when punching it at higher revs so I decided to lower the needles slightly this morning (equivalent to half a notch). Took it out this PM and it runs perfectly, no smoke or hesitation, great response at all speeds. I will run it this way for a while to get a better evaluation.

Intake is definitely audible now too.....

P.S. FWIW, I smoothed off the ridges (ie. corners) on the edges since this pic was taken; the arc from the edges to the filter medium is now lower and smoother, the idea being to improve airflow between the tank and lid.

[Kev L]

.....yet another plaster I see Mik! Is this just an excuse to self harm??

[mik_str]

Nope, that's the same one.... my mom was Scottish so I'm trying to get my money's worth....

[Kev L]

damn that must be a record for plaster usage! Even AMcQ ain't that tight (insert squeaky elbow sex reference here......)

[mik_str]

aye, me mum's right proud o' me

[VTRDark]

Are you using the HRC needles with this Mik?

Don't know if you have seen this, but there's an interesting jetting thread over in Oz with snorkel removal.
http://ozfirestorm.proboards.com/thread/11862

(:-})

[mik_str]

Yes, using the HRC rich (ram-air) needles

and thanks for the link, I will check it out.....

[lloydie]

Are you getting this one on the Dyno?

[mik_str]

perhaps at some point.....

[mik_str]

Well, I finally got my jetting sorted (arrived at after about a dozen incremental changes). I am currently running the "Gen II" (the one with the rectangular filter element directly over the stacks). My final settings are the following:

pilots: 40 (not a misprint.... yes, 40s; tried 48s, 45s, 42s along the way...)

fuel screws: F - 5/8 out, R - 7/8 out

needles: HRC rich, 3rd clip, shims: F - 0.003", R- 0.010"

mains (DJ): 170 F, 175 R

springs: DJ

slides holes: one OEM hole and one smaller one (could find the actual size if anyone wants the specifics).....

It now (finally!!!!!!) runs clean across the board (clean from 2000 rpm) with no flatspots whatsoever. Power and response are most impressive, very linear and immediate. Before anyone asks, no dyno testing has been done, likely none for the foreseeable future. However, having spent over 200,000 kms on the bike (and a lot of time tuning it through numerous iterations), I have a pretty good idea of how it runs, and it has never run as well as it does now. It runs much better (stronger, more responsive) than when it dynoed 122hp and 77 lb-ft...... Fuel mileage is pretty good too (was at 5.1L/100 km last time I checked)

FWIW, in switching back and forth between the Gen I (with large triangular Z1000 filter at front) and the Gen II, the Gen I needs leaner fuel screw settings. I should note too that I am running the high-level link pipes on my Akra full system (this, too, requires leaner fuel screws than the low/std mount link pipes). The engine seems to pull stronger at low and mids with high pipes (right smack where I ride most of the time). I may get around to giving the Gen I another try, but having taken the carbs apart many, many times since the spring, I now just want to ride and enjoy it for a while.

cheers

[NZSpokes]

This is to good not to try. I do wonder how far the settings will be off for a standard motor.

Did you lower the height of the lid as well? Without having the stock air filter it wont have enough room to breath?

[VTRDark]

after about a dozen incremental changes).

Oh I know that feeling but at least you have the flo commander to save taking the carbs apart again once your close.

no dyno testing has been done, likely none for the foreseeable future. However, having spent over 200,000 kms on the bike (and a lot of time tuning it through numerous iterations), I have a pretty good idea of how it runs

As you know Dyno's don't always give a true representation and real world testing is needed. I trust you know your bike pretty well and can feel the changes, well you should do with your experience and amount of time spent on things.

40s ay not heard of anyone using them on these bikes before but if that's what works then that's what works.

Fuel screws: F - 5/8 out, R - 7/8 out

What's that in turns then. Mmmm 1/2oz and an 1/8th and 1/2oz and three 1/8ths. Do you get medical Marijuana in Canada, I think I may need some

So you have experimented with different size slide holes then. Interesting! no point in telling us the size as every bike will be different and yours is tuned to yours. Any info on the effects larger or smaller holes had and more to the point how drastic the changes where. I'm guessing you have filled with resin and re-drilled the slides a few times. Did the smaller 2nd hole take a bit of slide bounce out by any chance? Are you still running Dr Honda's?

(:-})

[mik_str]

Carl, Carl, Carl... what is to be done with you? lol

regarding the fuel screws, it refers to the numbers of turns out from fully bottomed (so yes, they are quite lean)

In my experience, the number of holes affect slide lift speed. I tried many configurations, up to and including 4 holes. With too much "holeage" (lol), the lift lifts too quickly, leaving a puff of unburned fuel when cracking the throttle aggressively (granted, I have an HRC tube so it doesn't take much movement to get you into rapid slide movement territory). It doesn't affect much else (never paid attention to slide bounce as I can't say I ever really felt its effect, except perhaps at idle).

I too was (and remain) quite surprised by the small pilots (truthfully, I could/should be using 38s with the fuel screws set at around 2 turns out), but the engine doesn't lie. The needle and mains are also leaner, though not quite to the same extent. My only explanation is that the lid flows so much more air, that it increases the "pull" through the jets, flowing a lot more fuel through the jet. Only by using a significantly smaller jet (hole) can this extra vacuum be countered. An engine being a fancy air pump, I see this as being very positive, since reduced resistance to airflow (as is the case when the engine has to breathe through the snorkel) prevents the engine from operating at its potential (something Roger noted when I showed him my post-rebuild dyno results; he noted the the engine should be producing more if only it could breathe better). It now breathes... and runs very, very well.....

Finally, I am indeed using the HPower long trumpets.......