My bike is a Venture and Vmax Hybrid. In a nutshell: Vmax engine in a Venture.
Compression is good (160-170 psi) and valve clearances set. carbs are clean (ultrasonic bath).
Airbox is a flat panel insert since the VBoost manifold made the stock venture airbox too tall to fit under the cover/faux tank. Basically, too a slice out of the OEM airbox and made a flat panel adapter, then built a cover for the flat panel. The airbox opening is bigger, but not overly so. Probably not making figuring out the jetting any easier, but it doesn't make it impossible.
Exhaust is the stock venture headers and collector with a couple R1 mufflers. Little extra flow, but not much more.
With 37.5 pilots, needs 3.5/4.5 turns out to get CO at 3.5%. So they're too small.
Tossed in a set of 42.5 jets. That's all 1 turn or less to get the CO at 3.5%. So too big.
HAve a set of 40 pilot jets on order and we'll see what we get. Logically, 40 is square in the middle between 37.5 and 42.5 so that should put the mixture screws right in the middle around the 2-2.5 out mark.
The 37.5 pilots actually allowed it to run decent, until hitting cruise speed at the 1/8 throttle (approx 50 mph). Then it started breaking up and missing. My needles are adjustable (OEM) and raising them one notch vastly lessened the tendency to miss at cruise.
I never got to riding it with the 42.5's as it was very touchy to even get the Co within spec, the carb balance stable and rpm right. You could literally just touch the mixture screw with the screwdriver and change the CO readings to way lean. Just too touchy all around.
Also found the wet float levels are a little low (18-19 mm), I plan to bring that back up to the 16-17mm mark.
Hopefully, the 40's put the mixture screws in the right range to fatten up the transfer ports enough that cruise doesn't go lean like it does with the 37.5's and lets me keep the needles close to center adjustment.
Then, figure out the mains. Should be easy (famous last words!) after this quagmire is sorted....
Compression is good (160-170 psi) and valve clearances set. carbs are clean (ultrasonic bath).
Airbox is a flat panel insert since the VBoost manifold made the stock venture airbox too tall to fit under the cover/faux tank. Basically, too a slice out of the OEM airbox and made a flat panel adapter, then built a cover for the flat panel. The airbox opening is bigger, but not overly so. Probably not making figuring out the jetting any easier, but it doesn't make it impossible.
Exhaust is the stock venture headers and collector with a couple R1 mufflers. Little extra flow, but not much more.
With 37.5 pilots, needs 3.5/4.5 turns out to get CO at 3.5%. So they're too small.
Tossed in a set of 42.5 jets. That's all 1 turn or less to get the CO at 3.5%. So too big.
HAve a set of 40 pilot jets on order and we'll see what we get. Logically, 40 is square in the middle between 37.5 and 42.5 so that should put the mixture screws right in the middle around the 2-2.5 out mark.
The 37.5 pilots actually allowed it to run decent, until hitting cruise speed at the 1/8 throttle (approx 50 mph). Then it started breaking up and missing. My needles are adjustable (OEM) and raising them one notch vastly lessened the tendency to miss at cruise.
I never got to riding it with the 42.5's as it was very touchy to even get the Co within spec, the carb balance stable and rpm right. You could literally just touch the mixture screw with the screwdriver and change the CO readings to way lean. Just too touchy all around.
Also found the wet float levels are a little low (18-19 mm), I plan to bring that back up to the 16-17mm mark.
Hopefully, the 40's put the mixture screws in the right range to fatten up the transfer ports enough that cruise doesn't go lean like it does with the 37.5's and lets me keep the needles close to center adjustment.
Then, figure out the mains. Should be easy (famous last words!) after this quagmire is sorted....