05 Stella pinasco 177 new to me
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Member
2006 GTS250
Joined: 28 May 2013
Posts: 6
Location: Bothell, WA.
Thu Sep 19, 2019 7:21 am quote
Hey Everyone, so we have a bunch of misc. scooters, but the wife and I just picked up our first “legit” Vespa’s.
She got a GT200l
And I a Stella 150.

Both have a few issues, but the Stella is a mess.
It is a 2005 150 with, I am told big bore kit.
Looking at it, I believe it to be a Pinasco as it is an aluminum cylinder, and the head appears to match what I have seen of them too.
The motor starts and idles great, but has NO top end power at all, and sputters it’s way to a top speed of maybe 40mph.
I did a proper 4th gear plug chop and the plug looks about perfect.

I have the 20/20 carb (totally open to changing it out).
I cleaned the jets and filter, but (like a dummy) did not look at the jet sizes. I will correct that today.

Anyone have some experience with these kits and the proper tuning/install of them?
Thanks for your assistance!
Ossessionato
05 Stella, '62 VBB, 76 Sprint V, 63 GL
Joined: 16 Jun 2011
Posts: 2153
Location: Chicago. Well, Evanston, but that's almost Chicago
Thu Sep 19, 2019 11:02 am quote
How much work are you able/willing to do to get things going right?

A Pinasco 177 on a stella should be able to run at 55 to 60 mph all day long.

Before you take a look at any new parts, start with cleaning the carb, especially the main jet. Post what jets are in it.

Second, have you replaced the spark plug? It may just be fouled, which tends to show up as poor idle and crappy hi RPM performance.

Third, how is the compression? Do you have a tester to confirm you have at least 90 PSI? If not, how hard to you have to jump in order to kick it over?

Third, can you confirm the timing is correct? It should be at 18 BTDC. My 05 Stella came with the timing set at 24 BTDC and the flywheel over-torqued such that I had to destroy the flywheel to get it off and fix the timing.

At the same time, with a timing light, you can see if the timing is holding steady or missing/jumping at higher RPM's, which you wouldn't be able to hear when rev'ing the motor in neutral, but will prevent it from rev'ing out or producing adequate power under load.

Beyond that, first step is probably determine if you still have the catalyzed exhaust on it. If you do, get rid of that thing and get a SIP Road or BGM Bigbox ASAP.

Past that, we're starting to get into real improvements...
Member
2006 GTS250
Joined: 28 May 2013
Posts: 6
Location: Bothell, WA.
Thu Sep 19, 2019 1:22 pm quote
chandlerman wrote:
How much work are you able/willing to do to get things going right?

A Pinasco 177 on a stella should be able to run at 55 to 60 mph all day long.

Before you take a look at any new parts, start with cleaning the carb, especially the main jet. Post what jets are in it.

Second, have you replaced the spark plug? It may just be fouled, which tends to show up as poor idle and crappy hi RPM performance.

Third, how is the compression? Do you have a tester to confirm you have at least 90 PSI? If not, how hard to you have to jump in order to kick it over?

Third, can you confirm the timing is correct? It should be at 18 BTDC. My 05 Stella came with the timing set at 24 BTDC and the flywheel over-torqued such that I had to destroy the flywheel to get it off and fix the timing.

At the same time, with a timing light, you can see if the timing is holding steady or missing/jumping at higher RPM's, which you wouldn't be able to hear when rev'ing the motor in neutral, but will prevent it from rev'ing out or producing adequate power under load.

Beyond that, first step is probably determine if you still have the catalyzed exhaust on it. If you do, get rid of that thing and get a SIP Road or BGM Bigbox ASAP.

Past that, we're starting to get into real improvements...
Hey, thank you so much, this is exactly what I was hoping for, solid technical advice from someone with experience!😊

I’m looking to build a modest little hottod. Something relatively fast, but reliable enough to tide most anywhere.
I have other scoots, so I don’t mind doing extensive work to make it work right. I got it for about $500 and it is really clean and solid, so I got a great base to mess with.
I have been a motorcycle mechanic for a very long time, so tools and expertise is not a problem, however, this is literally the first time I have even touched a 2t vespa/Stella, so I have a glaring experience gap there😂

I will check the current jetting and toss in a new plug and check the timing, then get back to you.

Really appreciate all the help I can get! Eric
Member
2006 GTS250
Joined: 28 May 2013
Posts: 6
Location: Bothell, WA.
Thu Sep 19, 2019 2:00 pm quote
I don’t know what “box type” muffler I have, but it is quite loud, so almost certainly not the catalyst OEM one

2C179F6D-6061-4DF1-95D0-2E1126D85933.jpeg

Member
2006 GTS250
Joined: 28 May 2013
Posts: 6
Location: Bothell, WA.
Thu Sep 19, 2019 2:01 pm quote
I don’t know what “box type” muffler I have, but it is quite loud, so almost certainly not the catalyst OEM on

2C179F6D-6061-4DF1-95D0-2E1126D85933.jpeg

Member
2006 GTS250
Joined: 28 May 2013
Posts: 6
Location: Bothell, WA.
Thu Sep 19, 2019 2:04 pm quote
I will almost certainly go with an expansion chamber exhaust some time soon.
Most likely I will make it, if I can find one with good power characteristics to copy.

7C46F3DD-4128-46F4-87C8-83079A2AC140.jpeg

Ossessionato
05 Stella, '62 VBB, 76 Sprint V, 63 GL
Joined: 16 Jun 2011
Posts: 2153
Location: Chicago. Well, Evanston, but that's almost Chicago
Thu Sep 19, 2019 2:31 pm quote
Did the bike come without a cylinder shroud? The cylinder should be covered so that the cooling air from the flywheel keeps it cooled.

If it's been ridden like that, it may be that it's been seized enough to trash the rings and possibly even the piston or cylinder.

That means time to pull the head and inspect the bore. While you have it open, assuming the cylinder isn't trashed, you can measure the port timings and figure out how far from optimal the cylinder setup is.

Eventually, you'll want to pull it and (most likely) need to open up the transfers, but that's a little further down the road.

In the immediate-term, I'd check the timing and also whether or not the CDI is dying, which could easily produce the sort of issues you're seeing at higher RPM's. I've found that a dying CDI starts to degrade performance past about 4,500-5,000 RPM's but will still run for long periods of time. It's one of the more commonly misdiagnosed problems that Stella's have, because people chase jetting rather than fixing the real problem.

And, yes, that does not look like the catalyzed exhaust. It has a small heat shield where the pipe enters the box.

I would spend a little time around bikes with tuned pipes before I put much time, effort, or money into one. They are incredibly loud, to the point that I'm uncomfortable riding them both because I'm deafened even with a helmet, and I'm embarrassed to think I might be irritating the neighbors and waking the dead.

For some basics of tuning & porting a Stella in a relatively stock configuration, search on here for Blake7Even's "Sprint Sleeper" thread and my Porting 101 thread, both of which cover a lot of stella-specific tuning detail. For more general tuning guidance, this thread is a good place to start laying out your objectives, budget, and other information that will help us help you.

Welcome!

-chandler
Member
2006 GTS250
Joined: 28 May 2013
Posts: 6
Location: Bothell, WA.
Thu Sep 19, 2019 5:01 pm quote
Thanks again Chandler!
No, I took the shroud off to inspect, and I will be pulling the head off to inspect.
I did let my 11 year old son poke it up the block and back however😉

04849C25-AB0F-4DF6-9EED-AE0B216BD470.jpeg

Veni, Vidi, Posti
74 50s x2 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
Joined: 22 Nov 2010
Posts: 7062
Location: seattle/athens
Thu Sep 19, 2019 5:41 pm quote
Nice looking bike & welcome. Please gimme your screen name!

I have a little experience & a few parts I don't need. Usually know what to look for, though I don't use aftermarket cylinder kits much. I have time(retired) &, some tools. Would likely check compression & timing and have a variety of jets on hand. I'm just south of Kenmore, so close too.

Your kid looks thrilled!
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