Re: Peugeot 103 70cc Metrakit

Set your piston in the cylinder with the bottom of the piston skirt dead eaven with the cylinder skirt. Mark a line on the piston across the top of the gaping hole you've carved in to the cylinder skirt. Then mark lines strait down from there. Like this...

artflow_202009151008.jpg

Re: Peugeot 103 70cc Metrakit

Dirty30 Dillon /

Pulling out the bridge in the skirt, AND full on notching the piston is gonna be really unbalanced.

With the same kit on Derbi, notching the piston fully, vs. putting a window in it (matching the skirt window) decreases ring life substantially.

Re: Peugeot 103 70cc Metrakit

15469079-45F9-47D7-B169-1F5EA71B4BBA.jpeg

Let that beast breath.

Re: Peugeot 103 70cc Metrakit

> Dirty30 Dillon Wrote:

> -------------------------------------------------------

> Pulling out the bridge in the skirt, AND full on notching the piston is

> gonna be really unbalanced.

>

> With the same kit on Derbi, notching the piston fully, vs. putting a

> window in it (matching the skirt window) decreases ring life

> substantially.

Yes! I did not see your post until after I posted

Re: Peugeot 103 70cc Metrakit

DrGeorgeTompson (Alan) /

> EH FCC of the QCB Wrote:

> -------------------------------------------------------

> >

> Let that beast breath.

Yeah I probably should have done that. I ran out of effort after making this look nice.

IMG_20200915_123946.jpg

I was this close to cutting it the whole way down, but I'm glad I didn't. I'm just glad some juice is going to go right to the bearing.

It's all buttoned up. Squish around 1.2mm which is good enough for me. I'll put the rest on and time it tomorrow and hopefully not explode it immediately.

IMG_20200915_141408.jpg

Dirtbag head lol

Re: Peugeot 103 70cc Metrakit

DrGeorgeTompson (Alan) /

Goddammit I'm gonna open it back up and make the window taller. This shit looks fuckin stupid.

I'll be less drunk tomorrow lol

Re: Peugeot 103 70cc Metrakit

While you're at it , you might consider rounding the square corners .

Sharp angles seem to promote cracking quicker .

Look the piston over and note the lack of sharp corners , other than an outside edge . That should provide a pretty good clue . ;)

Re: Peugeot 103 70cc Metrakit

> DrGeorgeTompson (Alan) Wrote:

> -------------------------------------------------------

> Goddammit I'm gonna open it back up and make the window taller. This

> shit looks fuckin stupid.

>

> I'll be less drunk tomorrow lol

Yesssssss

I may have got carried away on the Vouge....🤣 (edited)

7B834A79-6D92-4509-A25C-EA7D2873DABB.jpeg

Re: Peugeot 103 70cc Metrakit

Unbalanced and won’t work huh? I must have been building my derbis wrong for years! Weird. Oh well

Re: Peugeot 103 70cc Metrakit

Dirty30 Dillon /

> Buttcheeks BUZZARD Wrote:

> -------------------------------------------------------

> Unbalanced and won’t work huh? I must have been building my derbis wrong

> for years! Weird. Oh well

Unbalanced, yes, of course. Never said it wouldn't work.

Re: Peugeot 103 70cc Metrakit

A lot of the rippiest +15hp scooter kits don’t have windows in the piston, most have a small notch on the intake side. With case induction you don’t need Swiss cheese out the piston, you’re gonna see more gains opening up the C transfers.

Re: Peugeot 103 70cc Metrakit

Tommy we already know they blast! I like to keep the bottom on my pistons to be a little more balanced. Either way they should have 360* intake duration. I my mind I feel like the ring will last longer. Who knows if this is true. I have seen some pistons what were modified by someone else a long time ago that have lighted the inside on the exhaust port side. Well only two like this. I thought it was interesting....don’t know if it did anything but it was I interesting.

Re: Peugeot 103 70cc Metrakit

DrGeorgeTompson (Alan) /

Now we're cooking with ass

IMG_20200916_115317.jpg

Would you people make up your minds lol

I'll let you know of this is any different than the unholy piston

Re: Peugeot 103 70cc Metrakit

Dirty30 Dillon /

> Daniel '' Wrote:

> -------------------------------------------------------

> A lot of the rippiest +15hp scooter kits don’t have windows in the

> piston, most have a small notch on the intake side. With case induction

> you don’t need Swiss cheese out the piston, you’re gonna see more gains

> opening up the C transfers.

This is actually really true. Both the Athena 47.6 (MinaHor) and the Polini Evolution II 47.6 (Piaggio Pent.) I have are just solid pistons. The Athena is rated for 16hp, and the Polini for like 20hp. Also, the Polini has a nozzled exhaust.

Re: Peugeot 103 70cc Metrakit

> DrGeorgeTompson (Alan) Wrote:

> -------------------------------------------------------

> Now we're cooking with ass

>

> Would you people make up your minds lol

>

> I'll let you know of this is any different than the unholy piston

Damn fine job there, you should see my ported tomos pistons, I couldnt get my lines that straight to save my life

Re: Peugeot 103 70cc Metrakit

DrGeorgeTompson (Alan) /

> Toledo Riot Wrote:

> -------------------------------------------------------

> Damn fine job there, you should see my ported tomos pistons, I couldnt

> get my lines that straight to save my life

Aw stop, you're making me blush

I REALLY like working with a Dremel; pretty sure I'm better with it than a writing stick.

16002790804991905392462296364162.jpg

I bought this piece of shit baby bench grinder from harbor freight a while ago (don't get me wrong it broke the second time I used it but I like fixing stuff so I did) and it has a flex shaft Dremel thing on it. The extra rotating mass helps so much with not having the tooling big down. It was actually very pleasant to do the cutting on this jug compared to the first one I did with a regular Dremel.

All that said, I think the huge piston window may have been a waste of time. I rode to the liquor store to get cigarettes (albeit only 3 or 4 blocks with mostly stop signs) and I couldn't tell you if it was any different than the uncut one. Maybe more torque? Idk my butt Dyno is fucked up because I've only been riding Revel electric scooters for like the past month.

Granted, I have not wound the motor out yet so who really knows yet. I'll keep y'all posted. Runs good tho. Much less slappy. Still kinda noisy tho. Idk. It's really hard to hear anything over the exhaust spring buzz most of the time.

Re: Peugeot 103 70cc Metrakit

Nice!!! Window looks awesome.

Re: Peugeot 103 70cc Metrakit

You gotta link to that flex head grinder? Been looking for somthing like that.

Re: Peugeot 103 70cc Metrakit

DrGeorgeTompson (Alan) /

> Aaron Blair Wrote:

> -------------------------------------------------------

> You gotta link to that flex head grinder? Been looking for somthing like

> that.

https://www.harborfreight.com/bench-grinder-with-flex-shaft-43533.html

It's 3 inch and I haven't been able to find a wire wheel that fit the arbor yet. Granted the weird abrasive foam thing that came with it works pretty good for removing rust and shit.

Also don't forget I said it broke the second time I used it lol. I had to solder something back onto the little board in it. Not too hard

Re: Peugeot 103 70cc Metrakit

DrGeorgeTompson (Alan) /

The windows not as straight as the other picture made it look but it's good enough for mopad work.

IMG_20200916_120357_01.jpg

So I guess there was a lot of stuff about the motor that was going on but I left out of the thread. Particularly, when it get up in revs the fuel in the carb starts to foam and it leans way out and pretty much cuts out. The extra vibration from the Swiss cheese piston seems to make that worse. I suppose that is expected. So far I've only been able to get around 57 mph out of it.

Screenshot_20200917-125931.png

It still runs very cool in mostly sub 300°F. I guess it has more power at lower rpm? Like I feel like I could add a tooth in the front and it would generally be a happier running bike. I dunno.

I've had a lot of trouble with the nut on the polini spring undoing itself and running away in the street with most of the other bits. Ive tried loctite but that's only really good for one setting then you need to take it all off, clean it, set it again and re-loctite it. I think I want to see if I can find a long m8x1 or whatever it is to put on there and then a nylon locknut to jam with.

It's still a fun bike but all together I am kinda disappointed so far. I shall continue to tinker as it is the only thing to do.

Re: Peugeot 103 70cc Metrakit

i used a copper crush nut on mine like vw use on exhaust manifolds and it has been gr8.

Re: Peugeot 103 70cc Metrakit

DrGeorgeTompson (Alan) /

> Daniel '' Wrote:

> -------------------------------------------------------

> i used a copper crush nut on mine like vw use on exhaust manifolds and

> it has been gr8.

Oh shit, I have a handful of those cause I was too lazy to wait for the copper ones in the mail before I put what I had on hand on it.

That's a good idea. Copper is cool

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