Right you are. I apologize for limited info supplied initially.

I ride at 300'-1000'; exaust is HMF wi HMF noise insert (really LOUD HMF!); top/snorkle is gone off air box & I'm running a Twin-Air filter with screen NOT removed; I bought the bike used about 1.5 yr ago & PO only owned it about 6 mo & had no clue of its history (but it was in really good shape wi <5k mi); I don't know for sure, but I doubt the cams have been touched. When I got it, it still had all the smog air lines to head (which I've removed/plugged) & still had the OEM tensioner (I've since installed a Krieger manual). Stock sprocket on rear; I've installed a 13T on the front. Other than a small bag/Renthals/woods mirrors, the rest is totally stock. It's a bitch to start if I dont drain carb after the previous ride, but once fired up/warmed up it runs great. Jetting/needle manipulations seemed to have no effect on that at all.

Never had any mechanical trouble with it in the 18 mo I've owned it.

Frankly, I have no intention of upgrading it to BB 351, so I'd like to maximize what I've got, without compromising reliablity.

I greatly appreciate you sharing the benefit of your experience on these matters!!!!

 

Alright, since this is not a jetting/setup thread, lets converse on PM or on a new thread that pertains to your bikes' setup..

 

If any of you get adventurous you can chuck a lean needle up in a drill and sand it down in the specific needed location along its length to richen it up. But you'd need an a/f meter to really know what's happening at a given throttle position.

SOTP tuning is filled with errors so often.

 

Richard, good to see a post from you.

Drill and sandpaper... I like it... have you done it before and when you did, what grit, wet or dry? Clearly not 80 grit. I've used as high as 1500 wet when polishing some Corean, definitely can leave a decent finish.

One other question. What exactly did you consider to be your preferred range with the A/F meter and what kind of variation did you experience with one specific jetting, based on weather change and all. I don't know if there is much of a variation in temps or whatever where you are, but I am curious.

It would be really interesting to see what would happen if KLXter could set his up in Texas, then go to a place like Wisconsin in the late fall, just to see how big the variation is. Maybe the same with altitude. Just to see how much change there is along with the SOTP feel. See some numbers related to atmospheric changes.

It would be cool to be able to do some of that here in Ohio with the relatively wide variation in weather conditions. Not much in altitude, only about 3000 feet total if you drop low and then go up in the Appalachians in WV. Of course it would take a shade more cash flow to play and this summer ain't makin' it. First grand child due in Austin, wife flying down shortly, wedding of youngest daughter here in Ohio, and wife has a wedding to attend in CA. Not a cheap summer. But what the heck... such is life.

 

KLX678, what you are talking about is a measurement called Density Altitude. Something we aircraft pilots calculate routinely and something that Speed-Density FI tuners must use to achieve perfect tunes..It is air density given as an altitude. So, I think a better comparison would be the hills of Seattle and Dallas. Same elevations but with fairly different dew points and temps - So lets pick a day...Say cool and wet in Seattle and hot, and a little dry, in Dallas.. Imagine these two different rides and how different the experiences are..Now lets look at the data:

Dallas 500', 90F, 29.92 , Dew Point 55F = 2770'
Seattle 500' 70F 29.92 Dew Point 68F = 1633'

So about 1K difference - So you could run the Dallas setup in Seattle with no problem. It would run a tiny bit more lean on that day in Seattle as there are more available oxygen molecules in Seattle on that day. (Lower density altitude)..

Once you have the density altitude calc that fits the situation, you correlate a main jet size from one location to the other with a altitude jet table..

Anyway, point is, it's all science - we don't have to run images of riding in the mountains vs the PCH, then kneejerk an opinion that no way could the setups be similar..

So, if I brought my bike to WI in late fall, it would already have a calculated "WI late fall" setup based off the setup I'm running now..
.

 

Your Ohio weather.. You could calculate a "best compromise" or drill down to a "summer", "fall", "spring", "winter".. Assuming there is enough variance to warrant a seasonal setup change.. All based and calculated off, say, one of my charted setups..

 

I apologize for not including you in the question I asked, an oversight on my part.

What I was actually asking was if anyone compared the extremes with the same jetting using an A/F meter? That would be interesting. Just how far does it drop or rise?

Clearly for peak performance racers will vary jetting at the same elevation under differing weather and temperature conditions, but road and play riders just don't do that. With all the knowledge, especially that which you have from aviation, are you able to get a general jetting that someone riding from Virginia Beach, VA to Columbus, Ohio (for example) can run? How does the average rider without the A/F meter and knowledge get there?

I never have had to do so with my 650, but I'm jetted lean and using the Dial-A-Jet, maybe that's why I don't notice differences, it does compensate for altitude with less fuel mix flow from the Dial-A-Jet injector. It will lean out as needed to the point where it is no longer a contributing factor. I've done from Daytona Beach to the mountains of WV and from 18°-95° without noticeable loss in performance. Doing the same with the 250.

Thanks for providing more for us. I'll have to read it about 3 times to absorb it.

 

I did it on an idle mix screw that looked to be a bit larger than the one it was replacing-but it was close so I just shined it up with the fine sandpaper dry and tried to eyeball whether it was getting any smaller.

Too hard to tell without calipers.

Here at sea level with 10% ethanol the only thing available, I think the supposed ideal a/f ratio was 12.2. Lately I'm as much for getting it in the same ballpark - as opposed to way too lean or rich. I'm not going to obsess about .5 either way because I'm not racing or doing roll ons with anyone so it's just not that important.

And that leaves some flexibility for weather changes.

 

Here are my measurements between the N1TC, the DJ, and the Stock needle:


https://i.imgur.com/HFsmAnL.png

Despite the N1TC sitting much higher up - and therefore being shorter in overall length, the diameters are almost identical to the DJ at the given heights when measuring from the needle clip seats. This would be the OD measurement that the needle jet would have as the slide moves up and down.

The n1tc appears to have the same taper as the stock needle, but due to the notch placements is pulled out much farther, resulting in an effectively more narrow needle.

very interesting.