Author Topic: I seek some thoughts on proper jetting with a Leo Vince ZXR install  (Read 3702 times)

wassonii

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This is all re: jetting the stock keihin pb16.
If I leave the airbox as it currently exists (snorkel still in), given what I have read, the idle jet should be okay left at 35, with the main jet 92,95, or 98 (starting with 98 and working down with chops.) 5 jets away from stock would be 95. SIP recommends about a 5% increase from stock, which would be about the 88 I currently have.
To throw a kink in the mix, I want to remove the airbox snorkel. To do this safely, I think I would need to increase idle to 38 and start main jet at 100 or 102 and chop til correct.
In all of this, I have that damned stock needle and plugged idle mix screw.
What do you think?
I do know I can't really dial in the CVT until the carb is good. I have a couple of weeks to contemplate and gather jets and plugs.
sans scooter, rien

wassonii

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Re: I seek some thoughts on proper jetting with a Leo Vince ZXR install
« Reply #1 on: August 06, 2012, 09:35:59 PM »
per Manny Hauswirth, US Technical manager with LeoVince:
"We develop our exhaust systems with the stock jetting. It shouldn’t be required to rejet the scooter when installing the pipe. When developing a pipe we test roller weights and clutch springs. If a benefit is found in adding them, we include them in the kit. The roller weights are included in this system."

One must, though, take into consideration that this testing is done with the restriction cone not removed.

Per Aeromyst:
"If you are still using the stock airbox, I don't think the jetting is
going to change a whole lot.  You may need to go up a little more on the
main, but plug chops are your best bet when tuning them in."

I am not going to remove the snorkel until I can get a decent carb on my scooter.
Bearing in mind that I am currently running an 88 with the Silent Sport, and it is too rich, I still plan on getting a variety of main jets from jetsrus and some plugs from partsforscooters.

sans scooter, rien

Psuffix

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Re: I seek some thoughts on proper jetting with a Leo Vince ZXR install
« Reply #2 on: August 07, 2012, 04:01:04 AM »
Good info there. I've been throwing around the idea of removing the restrictor on the airbox, not sure if I should though. Considering that I'm replacing the carb too I think I will. Seems like it must be one of the main restriction points. I have jets 80-125 on their way, so not really worried about not being able to go up high enough.

Aero makes it sound like the stock airbox just isn't going to be enough airflow for this pipe, especially once the tiny carb's out.

wassonii

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Re: I seek some thoughts on proper jetting with a Leo Vince ZXR install
« Reply #3 on: August 07, 2012, 07:49:07 AM »
Due to the not-truly adjustable needle and non-adjustable idle mix screw, there are definitely some lean-tending areas in the stock carb. That is a great range of jets you have coming! It shouldn't require the larger main jets needed for an open air filter, but will definitely require at least the high end of the 90's-plus, I should think, if not a little higher and the needle may need to go a little richer. It's not that the stock-form airbox airflow won't be enough, it's that the stock carb doesn't really allow for proper adjusting without the snorkel. And yes, the snorkel does restrict, especially once one begins the modding path.
sans scooter, rien

wassonii

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Re: I seek some thoughts on proper jetting with a Leo Vince ZXR install
« Reply #4 on: September 02, 2012, 02:24:05 PM »
What I have discovered:
Of note - I am in a location about 10 to 14 feet above sea level (effectively AT sea level)
It's not that the 88 was too rich on the Tecnigas, it was actually just right. 85 was a little too lean, 92 was too rich (and 98 was just way too rich).
With the Silent Sport I did try to remove the airbox restriction, but that little Keihin just couldn't handle it. 105 jet and wot had a good mixture, and a 38 jet was good for the idle, it was the darned mid-section that was very unhappy.
As to the LeoVince:
88 main jet was a little too lean. 95 was too rich (spluttering past half throttle). 92 is just right. Likely a hair or two rich, but very good.
35 idle jet was okay, but it's that darned needle again. I went to a 38 pilot due to the lack of true adjustability of the needle. If one could in a reliable manner adjust the needle, 35 would be okay for idle, but coming past 1/4 throttle, I could tell it was a little lean (sound and feel). 38 is a little too rich for idle to 1/4 but as the needle jet takes over the response is much better.
sans scooter, rien

wassonii

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I seek some thoughts on proper jetting with a Leo Vince ZXR install
« Reply #5 on: March 02, 2014, 12:37:44 AM »
Follow-up: The 38 was way too rich but it took me almost this long to go back. No harm, per se, but sh**ty gas mileage. I am of the opinion now that the 92 is really a skoche too big and a 90 will likely be perfect. I don't have one just now and will likely suffer a little longer until I can afford a Dellorto 17,5.
sans scooter, rien

245luigi

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Re: I seek some thoughts on proper jetting with a Leo Vince ZXR install
« Reply #6 on: March 04, 2014, 04:02:38 PM »
Oh my god Wassonii you're back!! Ive been using alot of your posts about the Like to upgrade mine. Hope you stick around, I'm hitting uncharted territory (70cc Malossi, with PHBG carb which is a pain in the ass to tune).

Thanks for the help dude, you're posts are great!

Currently:
2012 Kymco Like70
72cc Malossi BBK
Dell'Orto PHBG 19 AS Carb
52 Pilot Jet
92 Main Jet
W7 Needle, 40 Slide
2T atomizer + bushing
Tecnigas NextR Exhaust
TinyTach in Headset
2011 Kymco Like50 (stolen -> recovered)
PM's OK!

245luigi

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Re: I seek some thoughts on proper jetting with a Leo Vince ZXR install
« Reply #7 on: March 04, 2014, 04:09:19 PM »
Also, I was running a 90 with my tecnigas and it was perfect
Currently:
2012 Kymco Like70
72cc Malossi BBK
Dell'Orto PHBG 19 AS Carb
52 Pilot Jet
92 Main Jet
W7 Needle, 40 Slide
2T atomizer + bushing
Tecnigas NextR Exhaust
TinyTach in Headset
2011 Kymco Like50 (stolen -> recovered)
PM's OK!

wassonii

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Re: I seek some thoughts on proper jetting with a Leo Vince ZXR install
« Reply #8 on: March 04, 2014, 04:48:23 PM »
Don't ya just love the little beast?  That's a crazy beautiful carb that will sing when you get it right.
I haven't the space to do anything but tinker with what I have, so I am keen for your travels and travails.
Your posts are full of great infos, so thank you.
sans scooter, rien

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