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@snowytoes avatar
UTC

Lurker
PX125
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Location: Kent UK
 
Lurker
@snowytoes avatar
PX125
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UTC quote
Hi guy's, I am new to the forum, I have a bgm177 kit and have just split the cases of my px125 ready to get the ports matched. I have read about removing the gates on the barrel and widening the ports on the barrel then matching the cases.
Does anyone have experience of doing this?
Can pictures be posted if possible?
I would prefer not to have to weld the cases, can this be avoided?
Many thanks for reading and any responses 😁
@chandlerman avatar
UTC

Lucky
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 66 Lammy S3
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Lucky
@chandlerman avatar
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 66 Lammy S3
Joined: UTC
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154 Days Since Last Explosion
UTC quote
I've done it several times. I even made a video the last time I did it.

@108 avatar
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Ossessionato
V range 50s
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Ossessionato
@108 avatar
V range 50s
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UTC quote
If you weld the cases, try find someone good.

Potential failure points:
-Porous welding (crankcase leaks)
-Warping the cases

Someone who might have welded engine parts.

If not, I see a lot of European folk use this Weicon epoxy putty on Vespas.
Forum member supplied image with no explanatory text
OP
@snowytoes avatar
UTC

Lurker
PX125
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Location: Kent UK
 
Lurker
@snowytoes avatar
PX125
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Location: Kent UK
UTC quote
Thanks guys, I plan to avoid welding if I can, but I don't have a pre ported template to work from as in chandlermans video (which is helpful)
@subetherbass avatar
UTC

Ossessionato
1997 Italjet Formula 125, 2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
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Location: Australa, Mate
 
Ossessionato
@subetherbass avatar
1997 Italjet Formula 125, 2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: UTC
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Location: Australa, Mate
UTC quote
Keep grinding till you get bored, or go out to other side...
Start off with the biggest thing you can fit in there!
Start off with the biggest thing you can fit in there!
Remember to champher the edges
Remember to champher the edges
Make a few holes in the lightweight piston
Make a few holes in the lightweight piston
Grind off all the bits that cause seizes
Grind off all the bits that cause seizes
@christopher_55934 avatar
UTC

Ossessionato
2007 Stella 225
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Location: Rochester, Minnesota
 
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@christopher_55934 avatar
2007 Stella 225
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Location: Rochester, Minnesota
UTC quote
SubEtherBASS wrote:
Keep grinding till you get bored, or go out to other side...
Won't that cause a loose fit and piston slap?
@orwell84 avatar
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UTC quote
It's the Flinstone's racing kit.
@orwell84 avatar
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@orwell84 avatar
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I was reading an article about running more vs less oil in 2 stroke engines. One of the findings noted was that an underlubricated piston that was run hot and thrashed yielded an increase in hp in subsequent tests. I know that some types of automotive pistons had a deep cross hatch pattern on the skirts, though not to the extend of the piston shown.
@subetherbass avatar
UTC

Ossessionato
1997 Italjet Formula 125, 2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: UTC
Posts: 4855
Location: Australa, Mate
 
Ossessionato
@subetherbass avatar
1997 Italjet Formula 125, 2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: UTC
Posts: 4855
Location: Australa, Mate
UTC quote
Christopher_55934 wrote:
Won't that cause a loose fit and piston slap?
Nope, rings and bottom of piston are pretty much intact to ensure there is minimal slap.
Ground off bits were wherever there were seize points on pistons.
Cross hatching on exhaust to dissipate heat (something I learnt many moons ago from a tuner
@subetherbass avatar
UTC

Ossessionato
1997 Italjet Formula 125, 2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: UTC
Posts: 4855
Location: Australa, Mate
 
Ossessionato
@subetherbass avatar
1997 Italjet Formula 125, 2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: UTC
Posts: 4855
Location: Australa, Mate
UTC quote
I did however stuff up the head while putting "Singh Grooves" in it,as went too far into the squish area!
Groovy
Groovy
@oopsclunkthud avatar
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Banned
3:5
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Banned
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3:5
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UTC quote
Head design I did some time back
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@robbie_11 avatar
UTC

Hooked
PX
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Location: Switzerland
 
Hooked
@robbie_11 avatar
PX
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Location: Switzerland
UTC quote
Chandlermann, I have a silly question for you. Do you have any idea how much more power removing the gates and matcing the cases makes?
Is it a dramatic improvement or slightly noticable?
Cheers Robbie
@chandlerman avatar
UTC

Lucky
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 66 Lammy S3
Joined: UTC
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Location: Nashville

154 Days Since Last Explosion
 
Lucky
@chandlerman avatar
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 66 Lammy S3
Joined: UTC
Posts: 10360
Location: Nashville

154 Days Since Last Explosion
UTC quote
Robbie 11 wrote:
Chandlermann, I have a silly question for you. Do you have any idea how much more power removing the gates and matcing the cases makes?
Is it a dramatic improvement or slightly noticable?
Cheers Robbie
I've never done a "before and after" test, so I can't say for sure. I know that there was a difference between ported and unported on DR 177's. In the neighborhood of 3-4 HP for my Stella using GSFDyno, if I recall.
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