Modern Vespa

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 😁

I've done it several times. I even made a video the last time I did it.

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.

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)

Keep grinding till you get bored, or go out to other side...


Start off with the biggest thing you can fit in there!

Remember to champher the edges

Make a few holes in the lightweight piston

Grind off all the bits that cause seizes

Won't that cause a loose fit and piston slap?

It's the Flinstone's racing kit.

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.

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

I did however stuff up the head while putting "Singh Grooves" in it,as went too far into the squish area!


Groovy

Head design I did some time back

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.