OP
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Enthusiast
1961 VBB 150
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Enthusiast
1961 VBB 150
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Just putting a sparkling new malossi 166 on a freshly rebuilt p125x motor.
Question I have for the experts here:

1. which jet sizes would you recommend for break in and subsequent?
2. setting up an electronic stator. i have the head off and can easily see/feel TDC so don't really need the spark-plug-diy tool to find it, but assuming i'm very close to TDC, which way to rotate the stator (i understand rotating clockwise is retarding spark), and by how much.

I've found a couple references/answers to this, but they differ, and thought I'd ask from scratch to the experts here.

Thanks.
Tom.
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Hooked
cosa, rally, T5, italjet F125, Lambretta, plus junk
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Hooked
cosa, rally, T5, italjet F125, Lambretta, plus junk
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UTC quote
thought the malossi 166 came with jets??
my mates did..
@cazshie avatar
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2003 PX200
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@cazshie avatar
2003 PX200
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I have a 166 but too many other factors to consider to be able to give a precise answer.

You need to consider things like exhaust, carb size, etc as well.

Jetting will be trial and error but start high (especially during "run-in") and work your way down.

I have a 130 jet but also got a Sterling pipe and P2 carb.

Timing on mine is 18BTDC.
OP
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1961 VBB 150
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Enthusiast
1961 VBB 150
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gnasher. no it didn't.
cazshie. good point. i should have said... the exhaust is SIP road ... the expansion chamber kind that is more performance but kind of stock looks. carb is SI 24/24. what are you thinking for initial jet sizing and timing?
@cazshie avatar
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Hooked
2003 PX200
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@cazshie avatar
2003 PX200
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Location: Perth, Scotland
UTC quote
TomBot2000 wrote:
what are you thinking for initial jet sizing and timing?
It's not a disimilar set-up to mine so I'd be thinking 18BTDC for timing and starting with a 132 jet (certainly during the run-in) and working your way down with regular plug chops.

What about your plug? I changed from a BR7HS to a BR9HS

What's your other jetting set up as?
(I honestly can't remember mine, should probably write it down somewhere next time I have the carb open)
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Molto Verboso
71' Sprint Veloce , 05' Vespa PX150, 1978 P200E
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Molto Verboso
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71' Sprint Veloce , 05' Vespa PX150, 1978 P200E
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I just put a Malossi 166 less than one hour ago on my PX 150. My kit came with a 52-140 idler , a BE4 and a 115 main jet. Keep in mind that my kit is the 31 4093. Yours might be different. My PX started the first try with the electric starter.

The one thing I did not like is the fact that the metal gasket between the cylinder and the engine case was not matching much. I had a lot of gasket material showing on the inside of the engine. We ended putting a regular vespa/stella one and it worked fine.


My kit came with a thick copper cylinder head gasket and a rubber ring for the cylinder head as well.
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Banned
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@ scooterist,

do you find your idle jet boggy?

Ive just done the malossi route, had to put the std idle jet back in.

Ps dont forget to clean your air filter.
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Molto Verboso
71' Sprint Veloce , 05' Vespa PX150, 1978 P200E
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Molto Verboso
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I clean my air filters regularily. No, I didn't change the iddler, I just put what came with the kit. The idle is absolutely perfect, in fact it sounds as the standard cylinder.
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Sprint 166, P150S
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Without knowing what you have done to the engine or even which carb you are running (24/24?) then it's impossible to really answer this without the risk of you running lean or so fat that it feels like shit.

So what did you do on the inside? What crank are you running, carb, exhaust etc?
OP
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1961 VBB 150
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Yeah cazshie pointed that out above and I replied: "24/24. Sip road exhaust. P125x basis. Malossi 166 kitted"

The crank came with it and it looked great but don't know brand. It's been slightly cut, and polished.

I'm going with 120/be4/130 for main stack for break in. Thoughts welcome still. Thanks
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Ossessionato
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Ossessionato
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TomBot2000 wrote:
Yeah cazshie pointed that out above and I replied: "24/24. Sip road exhaust. P125x basis. Malossi 166 kitted"

The crank came with it and it looked great but don't know brand. It's been slightly cut, and polished.

I'm going with 120/be4/130 for main stack for break in. Thoughts welcome still. Thanks
Fine to start with a 130 main. You will be running very rich. You are probably around 115-120. Just start doing plug chops and down jetting until you get it right.
@eurochris avatar
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Hooked
1980 P125X / 1984 P125X
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1980 P125X / 1984 P125X
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Location: Portland, OR USA / Nürnberg, Bavaria, Germany
UTC quote
Hey,

So how is your setup treating you?

I am looking at putting together the same setup with the 24/24 carb, Malossi 166 kit and SIP Road exhaust here in Germany on my next P project, '84 PX125 Lusso.

I am also thinking about a cut 57mm Mazz crank over stock, any opinions on that, could I get away with stock? I may also buy a clutch plate a spring kit too as I've heard Cosas are for panzies...

Did you port match to the kit? How is the pick up and top speed? I heard that the Malossi 166 kit is known for top-end performance, anyway to get the bottom or mid range increased as well? Would the Mazz crank help with that?
@eurochris avatar
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Hooked
1980 P125X / 1984 P125X
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Posts: 124
Location: Portland, OR USA / Nürnberg, Bavaria, Germany
 
Hooked
@eurochris avatar
1980 P125X / 1984 P125X
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Location: Portland, OR USA / Nürnberg, Bavaria, Germany
UTC quote
Bueller?
OP
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Enthusiast
1961 VBB 150
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1961 VBB 150
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Hasn't seen it's first mile yet. I'll let you know.

It's been completely rebuilt. Almost back together And now is conerted to 12v with wiring I have yet to figure out so until then no feedback.

Also what I'll be comparing it to is so off the charts bad that it's going to be great no matter what.

I bought newly rebuilt cases and it had a cut crank in it already. I'm not sure what to say about port matching? The cases and the malossi kit are both 3 ports and they align... I'm not sure if people do more to them but I'd be happy with these parts unmolested in a tightly sealed engine. That would be heaven for me. Tuning beyond that to chase theoretical or real improvements is not my cup of tea.

I got the jetting info from my local shop expert. He said start that rich. Yes really. Then when it's running I'll bring it back by him and we'll adjust from there.

I'll repost then. Good luck with yours. Post your findings here too.

Cheers. Tom
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Sprint 166, P150S
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Location: Saigon
 
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Sprint 166, P150S
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Location: Saigon
UTC quote
Sorry Tom. Missed that initially.

I started with a 120/BE3/130. Finally settled with a 126 main jet. Starter is the 100/50 or 50/100 whichever way round it is. I've got a heavily cut HRS crank, Sco ot RS expansion pipe, T5 filter. Gickspeed worked head. I run a B8HS plug for town or 9 for long trips. 12,000km so far, no problems.

Hope that helps some.
TomBot2000 wrote:
Yeah cazshie pointed that out above and I replied: "24/24. Sip road exhaust. P125x basis. Malossi 166 kitted"

The crank came with it and it looked great but don't know brand. It's been slightly cut, and polished.

I'm going with 120/be4/130 for main stack for break in. Thoughts welcome still. Thanks
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