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Jetting a Polini 177
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Ace Rimmer UTC Hooked Mid 90's PX177E (Polini) Arcobelano Joined:UTC | |
OP Ace Rimmer Hooked
Mid 90's PX177E (Polini) Arcobelano Joined:UTC | UTCquote I ordered a Polini 177 cylinder from Scooter Mercato but cant find any info about which jets to use or what spark plug. I have searched here, scooterotica, modern buddy stella threads, lml owners uk, vespa uk, and another stella forum and found only speculation with little usefull knowledge. I keep reading tons of inconsistent advice and dead end threads that are never concluded. Some threads will say to use a 118 main while others say a 111, 110 to even as low as a 106. I want to order a spread of jets but not 13 jets at 5 to 9 bux a pop just to end up with a box full of jets I am never gonna use again. Some advice will come from people who say their motor is 'stock' but then say they have the cylinder port matched, a 24/24 p2 carb and a simoni, polini or other exhaust. Which I know effects jetting far more than a truely stock motor with just the cylinder bolted on. I'm lost here and have resorted to messaging random people on facebook and instagram that have pics of Vespa's in their albums. Does anybody know where I should start with a jet to work down from and what sparkplug to use? 118 main sounds far too large. |
Mattgyver UTC Addicted 1974 Rally 200, 1974 Rally 200 with sidecar, Vespacross bike Joined:UTC | |
Mattgyver Addicted 1974 Rally 200, 1974 Rally 200 with sidecar, Vespacross bike Joined:UTC | UTCquote B7HS plug. What carb and pipe are you running on your bike? |
rob hodge Molto Verboso
Joined:UTC | UTCquote well, really depends on what carb you are using. and what bike it is going on. and what exhaust you are using. and what altitude. you've honestly givven about as little info as you could; elaborate a little and i might be able to help you. i'd also dissregard any jetting suggestion that doesn't at least include the air corrector size also, as this strongly influences what mainjet you need. |
Ginch UTC Veni, Vidi, Posti 74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined:UTC | |
Ginch Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined:UTC | UTCquote Choose english at top right, then 177 from the drop-down list.... scroll down to Polini and you will find heaps of setups. |
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Ace Rimmer UTC Hooked Mid 90's PX177E (Polini) Arcobelano Joined:UTC | |
OP Ace Rimmer Hooked
Mid 90's PX177E (Polini) Arcobelano Joined:UTC | UTCquote rob hodge wrote: well, really depends on what carb you are using. and what bike it is going on. and what exhaust you are using. and what altitude. you've honestly givven about as little info as you could; elaborate a little and i might be able to help you. i'd also dissregard any jetting suggestion that doesn't at least include the air corrector size also, as this strongly influences what mainjet you need. It is going on a stock px150e with a 20/20 carb and a SIP Road 2.0 |
coco66 Hooked
Vespa PX 125 Joined:UTC | UTCquote my polini was just bolted on no porting, did have a P2 carb though. Main stack was 160/BE3/114. |
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Ace Rimmer UTC Hooked Mid 90's PX177E (Polini) Arcobelano Joined:UTC | |
OP Ace Rimmer Hooked
Mid 90's PX177E (Polini) Arcobelano Joined:UTC | UTCquote coco66 wrote: my polini was just bolted on no porting, did have a P2 carb though. Main stack was 160/BE3/114. After looking through the link Ginch gave me it seems I am gonna have to upgrade to a p2 carb, which I planned on doing anyways after breaking it in. Thanks for the help Ginch wrote: Choose english at top right, then 177 from the drop-down list.... scroll down to Polini and you will find heaps of setups. I stumbled across that page before but couldnt make sense of it, thanks for pointing out the drop box. |
Ginch UTC Veni, Vidi, Posti 74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined:UTC | |
Ginch Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined:UTC | UTCquote You're welcome. It's a bit annoying that you can't link to a particular page. It's also a bit frustrating to use, having to scroll sideways and then losing track of what the heading in a given column is... but lots of useful data there. That guy who is running Scootlist said he was going to have a similar thing but it doesn't seem to have happened. |
scooterist UTC Molto Verboso 71' Sprint Veloce , 05' Vespa PX150, 1978 P200E Joined:UTC | |
scooterist Molto Verboso
71' Sprint Veloce , 05' Vespa PX150, 1978 P200E Joined:UTC | UTCquote My stella had a 177 polini and stock carburator(20/20) and I was running a 125 main jet, BE3, 55 with a 266 hotwing exhaust then later a simonini. 125 seems to be working great for me but since you afre running a sito plus I would say, maybe a 120 main? my .2c |
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Ace Rimmer UTC Hooked Mid 90's PX177E (Polini) Arcobelano Joined:UTC | |
OP Ace Rimmer Hooked
Mid 90's PX177E (Polini) Arcobelano Joined:UTC | UTCquote scooterist wrote: My stella had a 177 polini and stock carburator(20/20) and I was running a 125 main jet, BE3, 55 with a 266 hotwing exhaust then later a simonini. 125 seems to be working great for me but since you afre running a sito plus I would say, maybe a 120 main? my .2c If I'm reading the chart from alexander-hepp correctly, I think 120 main is about right. I've got a 24/24 carb on the way now and I met a guy locally with a few tuned px's and hes got a collection of jets he's gonna let me use as long as I reimburse him for what I keep. |
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Ace Rimmer UTC Hooked Mid 90's PX177E (Polini) Arcobelano Joined:UTC | |
OP Ace Rimmer Hooked
Mid 90's PX177E (Polini) Arcobelano Joined:UTC | UTCquote Kit n Kaboodle Rather than start a new thread, I will just keep adding to this one. Got the polini in the mail today, mad thanks and big ups to Scooter Mercato! The package shipped Friday and arrived today (Tuesday), 16.1 lbs and it was only an $8 flat rate for shipping. Scooterwest, on the other hand, is breaking my balls, one $24 air filter (Scooter Mercato was out of stock) and they charge $13 for shipping, then I get it in a Flat Rate envelope. I guess that's the way mail order go, SM will mos def be getting all my business from now on, oh and Hodgespeed too, cuz SIP keeps rejecting my credit card and paypal for some raisin. I am hoping to bolt these on this weekend. More pics to come!
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Ginch UTC Veni, Vidi, Posti 74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined:UTC | |
Ginch Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined:UTC | UTCquote Don't forget to chamfer the port edges, they are pretty sharp out of the box. |
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Ace Rimmer UTC Hooked Mid 90's PX177E (Polini) Arcobelano Joined:UTC | |
OP Ace Rimmer Hooked
Mid 90's PX177E (Polini) Arcobelano Joined:UTC | UTCquote Got the kit chamfered and installed, running a 117 main jet for now. The plug looks a little rich and I will go down after I get a few more miles on it. It has some serious compression, the kick start has a lot more resistance. Idling it has a throatier sound and beefier through the revs. Off the line the torque is much greater, 1st gear doesn't even exist anymore and I have to shift immediately into 2nd once I'm moving. In 2nd and 3rd gear once I hit the mid range revs it pulls like crazy, so much more acceleration. It is almost scarry how hard it goes from tugging along to screaming down the road. I never got to 4th gear or got over about 65km/h. I have to torque the head down one more time before I take it for too long of a ride. The guy who did the work for me did a great job and he's gonna help me with the tuning after break in. The air filter I got from scooterwest for the 24mm carb had a casting mark that warped the seating surface to the carb and left a huge gap and was unusable. luckily he had a spare 24mm air filter as well as a ton of jets. I am very pleased with this set up and can't wait to ride it all over town. |
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Ace Rimmer UTC Hooked Mid 90's PX177E (Polini) Arcobelano Joined:UTC | |
OP Ace Rimmer Hooked
Mid 90's PX177E (Polini) Arcobelano Joined:UTC | UTCquote The nuts were fine but the carb needed to be torqued back down. I went for a short ride and am blown away. Even at 3/4ths throttle it accelerates much faster and takes off once in the mid range revs. 4th gear 3/4ths throttle cruises at 55mph and with a little more throttle I got to 60mph and still wasnt at wot. It engine brakes hard as soon as you ease off the throttle and when kick starting, it snapped back on me and caught the arch of my foot real good. There is so much power in this cylinder, I'm real happy I picked this kit. |
Ginch UTC Veni, Vidi, Posti 74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined:UTC | |
Ginch Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined:UTC | UTCquote Ace Rimmer wrote: ...It engine brakes hard as soon as you ease off the throttle... Now you probably need to upjet on the idle, because if you do that at speed you won't be passing enough fuel to keep it lubricated. |
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Ace Rimmer UTC Hooked Mid 90's PX177E (Polini) Arcobelano Joined:UTC | |
OP Ace Rimmer Hooked
Mid 90's PX177E (Polini) Arcobelano Joined:UTC | UTCquote Ginch wrote: Ace Rimmer wrote: ...It engine brakes hard as soon as you ease off the throttle... Now you probably need to upjet on the idle, because if you do that at speed you won't be passing enough fuel to keep it lubricated. There is a 50/160 in it now, the guy helping me out has a larger idle jet I can borrow. After putting 40 miles on the kit it is running a little smoother. The sound is less tin can and more dirt bike like, the engine braking is not as strong as my first ride unless I completely roll of the throttle. I though I soft seized it climbing a hill yesterday but I only ran out off gas from the 0.3 gallons I had in the tank sloshing behind the fuel tap. I am keeping both tanks topped off from now on. |
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