I finally installed my s type wheels(18/21), sm wheels off. Got tubliss on both. Just need to install the longer kickstand and space the front fender for clearance then I can see how bad I suck off road.
Thinking about going to a trials meet a week after Sunday and putz around the novice sections and if trials looks fun start saving up for a proper sled. I already think I will like it so I probably will.
Damn bike is almost too tall. On my tippy toes in my street shoes. Think I will need to back off the shock preload and pull the forks up with these wheels.

Before

After

 

Someone near VA Beach, take Snappster on a proper "intro to offroad" trail ride...?

 

wanna come up to new york next year ill take you on some, or guys in jersey have some really nice trails

 

S wheels are off, back to SF wheels and 15x39. The colder it gets the leaner the fueling feels so I moved the needle clip from N1 to N2 with no other changes. Earlier before I moved the clip I went for a little ride at around 23F and the engine never felt warmed up, regarding throttle changes and some slight surging at steady speed. Just started it up after several hours of cooling down with N2 and had the choke off quickly and engine takes throttle enough to pull wheelies within a minute. If fuel economy goes to hell I will try putting one washer under the clip at N1.

 

Snap, just remember that you cannot richen or lean your fueling curve with the clip position - you can only change the way the existing fueling curve is presented to the engine. Going to 2N presents a richer portion of the existing fuel curve sooner.

The main jet controls the richness or leanness of the fueling curve at all RPM's above idle.

The main jet does not control any fueling (nor have any effect) during idle and engine warm-up (choke on, throttle closed)..

WIth 2N running your engine better than 1N while "city" riding (low to med speeds and throttle) , you might want to finally take my advice on losing the lidless 250 jetting and going with 351 lidless jetting.. Meaning a DJ148 or K162, and back to 1N....

 

I had to patch my rear tube this weekend, looks like my rim lock might have pinched it a bit after 1500 miles of trail. I forgot how fun it is to fish the valve through the rim on a stiff set of sidewalls. (Note to self, buy one of those valve fishing tools)

While my hands were dirty, I modded the carb vent lines with Y fittings and hoses to the the airbox, and replaced the fuel line and filter between the petcock and carb with the premium Motion Pro stuff... nice and flexible (but $$).

Farted around the farm practicing low speed clutch/balance skill, steering lock figures 8's, and slow one handed or one footed riding on uneven terrain.... I suck at it and will never be even a junior grade Gumby rider, but I can pretend... LOL

 

I expected you would say something like this and that is good. I will order several new main jets and maybe a couple of larger pilots too, but until they arrive the 2N solutions was expedient and effective. What size pilot jet have you arrived at for BB351/lidless bikes?

 

Pilot jets on lidless 351 CVK's - you simply error on the side of safety. Get the #40 and adjust using the " halfway between rich/lean idle drops method", then forget it forever..

Once done, the #40 is also going to give you better throttle response..So grip tightly when snapping the throttle..

 

 

Snap, I understand that you highly value MPG. And the fact that you know E10 stoich is 14.1 means you are, at the very least, "capable".. To answer your specific questions regarding AFR, I am sorry to say that I have no charts to offer, only member reports.. But remember, I have never let you or anyone "down" regarding this stuff..

So, here we go..
It takes X hp to maintain Y speed. Taking ignition tuning out of the equation - because it is NOT IN the equation - you will make this HP with a set amount of fuel, You will deliver this exact amount of fuel regardless of tuning / tuned AFR. The difference is that lean / too lean requires a larger throttle opening than "just right". As a thought experiment, image a jetting that will allow the required speed, but only at WOT. In this, the engine is producing its' maximum power with the super lean AFR it is being fed, but the amount of fuel required did not change.

So, what to do. You find a main jet size that, along with all "other component settings", affords max power without overfueling - as overfueling wastes gas and "tanks" MPG.

In your situation, I have created the best "other component settings" for you, you will have to "sneak up" on the best main jet for your riding style and your requirements. Obviously, with a #40 and a DJ148 /K162, you are going to burn more fuel with every acceleration (throttle twist) than before, and in return, you will experience more power - as to how much more "thrill" you experience, that's personal to you, but is the single most important variable in this equation. In the last analysis, for you, when rat racing, it's likely going to be "thrill level vs Fuel burn".

In my testing, I found "2 jet size changes at a time" helped to zero in on the final jet, in a timely fashion. So, start with the DJ148, it has good dynobutt reports for lidless 351's.. Be sure you are running a stock slide lift port (and if not, JB weld it an redrill it with 5/64 bit) , stock slide spring, and 1N (clip on topmost notch)..