OP
UTC

Member
Motovespa 150s lambretta li150
Joined: UTC
Posts: 49
Location: uk
 
Member
Motovespa 150s lambretta li150
Joined: UTC
Posts: 49
Location: uk
UTC quote
Hi all
Now the weather is getting better i am going to try and get the vespa running better before I take it to the dyno. Life , kids work etc has got in the way and its now probably been parked up a year. I carried out the carb mod by drilling the hole bigger and not sure if I have buggered up the carb. A mate has lent me his si 24 to try so I'm looking for a base setting that would enable me to see if I need a new carb.

Specs are mallossi mhr 187
Si 24 no filter just rubber to frame
Mallossi mhr curly pipe.

Any suggestions on a base jetting set up would be appreciated as I now have more Jets than the RAF.

Take care all

Matt
@charlieman22 avatar
UTC

Nedminder
62 VBB1T Round Tail W/ leaner sidecar
Joined: UTC
Posts: 4023
Location: california
 
Nedminder
@charlieman22 avatar
62 VBB1T Round Tail W/ leaner sidecar
Joined: UTC
Posts: 4023
Location: california
UTC quote
Been a while since I was here - Jack would do better.
You will want to make it too rich - then take the main down until its right.
It sounds like the cylinder is new.
I will assume the motor is not.
I'm from the break it in quick school.
Has worked well for me.
Fair warning.

Starting point:
120 AC BE3 or BE4 and 130 main jet on drilled carb.
55/160 idle.

Note the drilled carb point. Your mate's carb, undrilled will throw things off as it will choke the fuel to the main - careful with that.

You want it to be rich enough not to rev out comfortably.
Then you start making the main jet smaller.

As for break in - I like to get the main jet about 1 or 2 sizes larger than optimal (using walk down method above) and get through the gears a dozen or so times.
Don't hang on any gear.
Don't rev to absolute max - but get it up close to peak with each shift.
Do that as many times as you or your neighbors can bear.
And it's ready.

Your cylinder is nicasil. The only thing you are breaking in is your rings.
You can opt to let it cool off and do the above a few times if it makes you feel better.
But it really doesn't take much more in my experience.

Robbie is breaking in a BGM of similar ilk - box exhaust - somewhere on here
You might search his and follow suit on your jetting as its a close build.
OP
UTC

Member
Motovespa 150s lambretta li150
Joined: UTC
Posts: 49
Location: uk
 
Member
Motovespa 150s lambretta li150
Joined: UTC
Posts: 49
Location: uk
UTC quote
Thanks for that thats great.

The kit is already run in so no problems there I couldn't get the 26mm carb any where near even when I put the sip 2 back on that was previously set up on a dyno with the same settings it was this that was making me think I had messed it up. If it runs a lot better I will buy another catb and fit it before the dyno run I was hoping to save lots of expensive dyno time.

Thanks again

Matt
@robbie_11 avatar
UTC

Hooked
PX
Joined: UTC
Posts: 326
Location: Switzerland
 
Hooked
@robbie_11 avatar
PX
Joined: UTC
Posts: 326
Location: Switzerland
UTC quote
Hi Matt
as Charlieman mentioned that Im running my BGM177 kit in at the moment.
The set up is no filter, starting jetting was AC120 BE4 MJ130 pilot 55/160 but it was way to rich with the 130 main jet.
I couldnt open past 1/2 throttle so I reduced to 128 which was still undriveable. Im now on 125 which is still rich and slightly spluttering but I can rev it out even though its spluttering which is safe.

If I was you I would start at a 130.
I also drilled out the carb and fitted a fast-flow tap.
Im in the process of fitting a temp-switch and Rev-couter which is really importantā€¦
Good luckā€¦
@psma avatar
UTC

Hooked
125 GTR 1977, 50S 1975, GTS 125 Supertech 2021
Joined: UTC
Posts: 277
Location: Madeira Island
 
Hooked
@psma avatar
125 GTR 1977, 50S 1975, GTS 125 Supertech 2021
Joined: UTC
Posts: 277
Location: Madeira Island
UTC quote
Hi, My BGM177 (Alu) is running great with AC160, BE3 and MJ140, SI24E. Maybe around 500km break-in? didn't check the spark plug since day one, as it runs smooth and healthy all rev range, will let it go as it is.

Burns fuel like spacex raptors but who cares? No more on the end if the tail, two stroke rules! Scooter emoticon Scooter emoticon Scooter emoticon
@charlieman22 avatar
UTC

Nedminder
62 VBB1T Round Tail W/ leaner sidecar
Joined: UTC
Posts: 4023
Location: california
 
Nedminder
@charlieman22 avatar
62 VBB1T Round Tail W/ leaner sidecar
Joined: UTC
Posts: 4023
Location: california
UTC quote
Are you running a bell mouth on the carb,

26 is rumored to be hard to jet in - but at the end of the day it's just air and fuel.

The process I noted will work.
The stack I suggested was based on 24mm but still. A reasonable place to start I would think.

Make sure u start rich and then begin stepping down the main jet on that stack until it begins to run better and rev out WOT. Bobs your uncle.
OP
UTC

Member
Motovespa 150s lambretta li150
Joined: UTC
Posts: 49
Location: uk
 
Member
Motovespa 150s lambretta li150
Joined: UTC
Posts: 49
Location: uk
UTC quote
Thanks all going to get cracking tomorrow got most of that in stock I think.

Take care
@jimscoot avatar
UTC

Addicted
PX 150
Joined: UTC
Posts: 577
Location: Gold Coast, Australia
 
Addicted
@jimscoot avatar
PX 150
Joined: UTC
Posts: 577
Location: Gold Coast, Australia
UTC quote
Malossi recommends the si24 with their sport kit and the 30phbh with the MHR kits
Which kit are you using again?
Forum member supplied image with no explanatory text
OP
UTC

Member
Motovespa 150s lambretta li150
Joined: UTC
Posts: 49
Location: uk
 
Member
Motovespa 150s lambretta li150
Joined: UTC
Posts: 49
Location: uk
UTC quote
Hi I am using the si 24 and it seems many do I really wanted to keep the auto lube maybe I need to have a rethink
DoubleGood Design banner

Modern Vespa is the premier site for modern Vespa and Piaggio scooters. Vespa GTS300, GTS250, GTV, GT200, LX150, LXS, ET4, ET2, MP3, Fuoco, Elettrica and more.

Buy Me A Coffee
 

Shop on Amazon with Modern Vespa

Modern Vespa is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com


All Content Copyright 2005-2024 by Modern Vespa.
All Rights Reserved.


[ Time: 0.0289s ][ Queries: 4 (0.0024s) ][ Debug on ][ 313 ][ Thing One ]