Modern Vespa

Hi All
Im contemplating fitting the BGM 177 kit to one of my PX scoots…
I know that this topic has been discussed many times before. I used the search but any feedback has been a while back so just wanted to ask a few questions:

1) The BGM /Scooter Center installation recommendations are written clearly, which is great….
On the carb side they recommend as a starting point:
24Si
125 - 130 MJ
55/160
BE3
Non drilled standard filter.

Not mentioned is either a Fast-Flow fuel tap or drilled fuel bowl inlet?
Has anyone set-up there BGM Kit as above or Is more fuel needed with the Fast-Flow fuel tap and drilled carb?
I will fit a new Polini box exhaust so nothing over the top…

2) Gearing wise I have a 22/68 clutch. Too short or is a 23/68 a necessity?
Im pretty light so no real weight on the scoot.

3) Overall feedback as a BGM 177 kit owner.
Are you happy with the BGM?

It would be replacing the basic Pinasco 177 Alu kit thats to say the least underwhelming..

Cheers Robbie

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BGM gives guidelines for the squish; i ended up using the head gasket and the middle sized base gasket. Use a fast flow fuel tap. I would move up the gearing if you are planning on doing a lot of touring; i myself do a lot of rural riding and appreciate it being geared higher. i would port the cases to match the cylinder.

It's a great cylinder kit for the money; you will be pleased and i like your simple approach (KISS-keep it simple stupid).

Last edited by GickSpeed on Tue Jan 25, 2022 2:22 pm; edited 1 time in total

Thanks Gickspeed,
Thats the sort of answer I was looking for…
I think I will do this in the cold winter months,
Then in summer I can plan a few nice rides over the border to Italy….

Thanks for the feedback…

I've been running a BGM on my LML motor since almost the first moment they were available, mostly with a crazy PWK/long stroke, but I'm about to build something similar to what you're doing, only with 8" wheels, so gearing will be a little funny.

First off, you're going to need a 140 Air Corrector, maybe a 120, and you're correct that you want to drill the float passage along with adding a fast flow tap.

Gearing-wise, What Gick Said.

Set up properly, you'll have plenty of power to drive even a 23/65 if you want to go that high, you just need to decide where you want the tradeoff between acceleration vs. top speed to be. If you're on a 22/68, that'll be a little short, but will certainly get the job done. The Polini exhaust is known for not having a ton of top end rev's, so you won't gain that much top end with it RPM-wise, but it'll have plenty of power.

Cut out the gates in the cylinder, then match those to the cases. They'll be BIG, but that's kind've the point. There's room to open up the piston windows too, but that's not strictly necessary.

Make sure you have adequate port timings and you will have a nice, fast motor with not a ton of effort. The head is immensely adjustable for squish since it seats into the cylinder. 0.8-1mm is what you should shoot for.

I agree with Gick and everyone else who's chimed in--it's a great cylinder with a ton of capability and easy to get set up. I think you'll really like it.

Thanks Chandlerman.

You say I will probably need a richer air-corrector, a 140 or even a 120 For the main stack.
You think the 160 is probably to lean?

Will the BE3 mixer tube work with the 140 air-corrector or should I go to a richer BE2 as well?

I will start with a 130 main jet…

Cheers Robbie

i used a 160/BE3/ and started at a 130 and worked down. I really can't remember where i ended up on the MJ. 24.24 Pinasco ER with a single pedal Polini reed. Ceramic coated Polini Box. I did not increase the gearing as a sidecar would later be attached. i would go 22/65 if no side car. . which would give you the option to go 23/65 if you felt you could pull it.

Great….
Thanks Givkspeed…

Just started your very same project.
'79 PX
BGM 177 -- cases ported
Polini box
Drilled bowl 2.4mm
Fast flow & braided 8mm hose
23/68 BGM clutch (not spitting cases)
BGM jetting kit for a px with 24 carb, made to go along with the BGM 177. Basically includes what you listed and MJ's from 115 to 138.

Give me a week and I'll follow up with how it goes!

BTW I'm surprised they recommend a stock filter.

Ray8 Pretty much an identical build as what Im looking at 👍.
Good luck and let me know how you get on…
Id be interested how you get on with matching the cases to the cylinder.
My cases are ported to a Pinasco so maybe just need minimal port adjustment with the dremel 😜

Cheers
Robbie

Mine was on a 2012 PX150, so had the 35T 4th gear, and I ran it with 23/68, a BigBox Touring, a sporty Jasil crank (57mm stroke), and enlarged inlet. Such a good performer, particularly with a passenger on long rides. Loads of useable power and great top end (it would go to 120 km/h on the speedo no problem). If you use the ports as it comes OOTB, you will need the Dremel, but you don't need to add any material. You can of course make the cylinder ports much bigger for a higher state of tune, but then the case ports will be getting a bit thin if you have the late PX engine.

My carb was a 24/24 with all the mods and a venturi, but I cannot remember the exact jetting. I always use fast flow taps whenever I build beyond stock.

Thanks Swa45
I wont touch the cylinder ports at all.
Only the casings at a minimal…Dont want to f@#k something up 😆

I think once you see the cylinder you'll change your mind about cutting the ports. They;re very thin bits of the casting that are very easily removed.

Hi Ginch
Do you have any pics of where you would recommend to cut/trim/shape the ports? I thought out of the box the BGM cylinder is pretty good?
I wouldnt know which ports to cut/trim/shape…

Hey bud. Can you post a picture of the 8mm braided hose? if not, can you post a link? I am curious on how it looks.

The BGM thin gates over its ports out of the box that match the ports on stock PX cases. I you want to minimize the changes, then take your existing base gasket, trace those ports onto it, then cut those back. You won't hit the edges of the BGM's ports.

I'll try to get you some pictures later today when I'm not supposed to be paying attention to conference calls...

Judging the two base gaskets, I'd say you're really close.


Pinasco

BGM

Not really, but it'll be perfectly obvious once you get hold of it. Here's some pics I found, in the first you can see that the cover/gate bit is fairly thin, and it's open underneath. The others show where you're cutting.
I guess the main thing is to match it up to your case.

When I bought my first BGM 177 back in 2016, I noted three options for the cylinder <> case ports:

1. Do nothing. The BGM has a 'gate' across each port on the bottom of the cylinder. This gate maps to the angled edge of the the stock case ports. In the first photo, you can make out the gate quite clearly on the left hand side.

2. Dremel the case ports to match the BGM cylinder and use BGM supplied base gasket. There is not much to do, as the stock BGM ports are not very big, and you'll go nowhere near the limits, so no additional material needs to be added to the casing.

3. Make the cylinder ports bigger and subsequently enlarge the case ports to match. This is what I did to match a Pinasco Magny Cours base gasket (see second photo). The first photo shows the blue Sharpie markings that I made. The Magny Cours kit has bigger ports than the regular Pinasco 177 kit. I did need to add material to the casing before doing the Dremel work.

Thanks chandlerman….

Thanks Ginsch,
Great photos….
I will get some dremel practice in, in the coming weeks…..😜

Looks like this:
https://www.dimecitycycles.com/5-16-clear-braided-fuel-line.html

If You are planning to Buy, and the BGM is not in your hands yet, just take a look at VMC Cylinders. SuperG or Stelvio. They are newer than BGM. Pretty strongs cylinders.

Thanks Mendozaram
But already ordered the BGM…..
The winner for me was the great set-up instructions and so far only top service and Support from Scooter Center Koln.

But you are right the VMC cylinders look nice.

Cheers
Robbie

There's a BGM 177 page on Facebook, might get some more specific information there.

Do you have a link?
Tried a search and only came up with rifle groups!

I'd really suggest getting the 23/68 clutch too. Just feels better, with no recognizable loss in pull power. A bolt-on addition with minor dremel modification to the stock clutch cover and removal of a segment in the case, which can be done easily.
There's a complete BGM clutch version for up to 15hp, at around half the price of the Superstrong.

Also, your new kit comes with a 10mm CHT port. I'd consider getting this as well, as an insurance policy while touring:
https://www.scooter-center.com/en/temperature-sensor-koso-m10xp1.0-for-koso-instruments-bf100000

Facebook group -

https://www.facebook.com/groups/362723164444452/?hoisted_section_header_type=recently_seen&multi_permalinks=925667544816675

thanks Ray8
I have the standard Cosa 2 clutch as ,ime is a late PX but have ordered this t replace the 22 ...

https://www.scooter-center.com/en/clutch-sprocket-bgm-pro-vespa-cosa2-px-1995-bgm-superstrong-superstrong-cr-for-67/68-tooth-primary-gear-helical-23-tooth-bgm6823s

Which temperature guage will work for this sensor?
Do you please have a link?

Cheers Robbie

My SI24 carb has a cutaway should i replace it with a fully closed slide?
This would make it richer..

https://www.scooter-center.com/en/throttle-slide-scooter-center-for-dellorto/spaco-si24/24-e/h-vespa-px200-cosa200-typ-8492-4-cutaway-100-mager-3331590

If you want to try a no cut out slide, if I remember correctly, you can tape over the oval shaped hole on top. That is where the bypass air comes from.

Here's the one I have. It comes with a 14mm sensor you won't need. Maybe cheaper without it:

https://www.trailtech.net/en-us/shop/accessories/digital-gauges/tto-mini-gauge/tto-temperature/surface-tto-temperature-black-cylinder-head-sensor-14mm/

SC has this kit with the sensor you need. No internal battery, though.

https://www.scooter-center.com/en/temperature-gauge-malossi-dual-universal-250c-2500c-130f-4820f-69mm-x-32mm-x-16mm-m5817491b?number=M5817491B

Thanks Ray8
I think i will go for the KOSO one..

Cheers Mate

I just removed the Pinasco Cylinder to clean everything up for the BGM…and found this….

A few years ago I gave the motor to a so called Vespa Garage to rebuild the motor.
Looks like someone got a little excited with the dremel…Im extremely pissed off..

I will be writing him a very strong worded email.
The problem is I dont even know what he used to try and fill the hole?
Its almost a yellow colour but its very hard.
If i put my finger on either side of the hole I can see the shadow of my finger on the otherside so Im not happy to leave it like this even though it still looks to be holding together.
Any advice would be welcome…
Should I back up the hole with some JB Weld or Liquid metal or get it welded up?

You can't avoid holing the cases when porting them. There's just not much "meat" there. Most people get them welded, others use JB Weld, etc. That yellow stuff looks like a type of resin epoxy, similar to JB Weld…

Thanks SaFiS For the feedback…

Plan A
Depends what you have access to, if you have a local source, get the holes welded up. Do some searching on here and you will find welded up cases for examples to show a shop.

Plan B
Clean everything up, really good and epoxy will stick. I've seen examples where people heated up area with a propane torch and sweat oil out of pores to make sure area is clean. You have an example showing it will stick.

Thanks….
I will go for the plan B I think as im in Switzerland and I think the welding of aluminum will be very expensive here and I woul brobably need to split the cases which I really dont want to do.
I have just ordered some JB Weld.
I will clean the surface with alcohol and fill over from the inside, leave it a few days and file smooth with a small rounded file…

Clean the surface with acetone, followed by brake parts cleaner if you can.

Since you're going to be applying over existing epoxy, you can't heat it with a torch or it will cause the epoxy to separate from the cases.

As others have said, welding on more aluminum is the ideal fix, but I've also used JBWeld successfully several times in the past.

Anything worth doing is worth doing right. Here are cases that I weld up. You may want to reach out to Ralph Bollag to see what he charges. TIG welding those should not be expensive and you would not have to mill the gasket surface.

Thanks Chandlerman