modpx
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Post by modpx on Jan 7, 2013 0:12:45 GMT
Just like to point out pinking IS NOT pre ignition, pinking is DETONATION both completely different. Pinking is caused by incorrect timing/carburation/compression or too large a squish, the other by the fuel/air mixture being ignited PRIOR it's pre determined ignition point. Pre ignition is usually indicated by a nice round hole in the top of your piston, whereas detonation usually produces a pockmarked piston most noticeable around the outer edge close to the exhaust port. A standard Pinasco kit generally has a very generous squish (over 2mm) reducing the chance of pinking as the compression is so low but it sounds as though you've fitted a 60mm crank so it may have raised your compression and reduced your squish. As has been mentioned check your squish.... solder down through the plug hole at right angles to the crank (to achieve a fairly accurate measurement,) and check the thickness...... between 1.2 and 1.6 is a safe measurement. next thing to do if it is detonation is to further retard your timing, you may have to file out the stator to achieve this......... retard your timing as far as it will go and then advance a little at a time until you reintroduce the pinking then knock it back again to the last safe point. Don't be fooled by the IT mark on the casings, it's a guide only. I've strobed scoots on the IT mark only to find that some have been running 20 deg BTDC and some running as low as 14...... so have it checked properly, or just keep retarding until the pinking goes away. Last point, Nik is right, never use a sealant (especially hylomar) on your head.......... it looks as though it's blown out from your pic which could actually be the cause of your woes. Quote: At right angles to the crank. [glow=red,2,300][/glow] Hi joey, could u please tell me exactly how?? Cause like i said before i put the solder wire into the spark hole but i cant see how the wire can be squeezed as theres no friction, compression, (in other words they don't touch each other )between the head of the piston, the wire and the cylinder head...
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modpx
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Post by modpx on Jan 6, 2013 22:50:18 GMT
Just skimming through here, so I may have missed something... You're using sealants? DO NOT USE SEALANTS!!!! It'll blow out eventually, then the engine will run lean, then you'll be back here again. Hmm..... 1.4 squish is deliberately on the safe side on mine. I don't want to break anything unnecessarily! Nik what type of set you have? For what purpose did u measure the squish if i can ask? thanks
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modpx
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Post by modpx on Jan 6, 2013 22:48:59 GMT
Just skimming through here, so I may have missed something... You're using sealants? DO NOT USE SEALANTS!!!! It'll blow out eventually, then the engine will run lean, then you'll be back here again. Hmm..... 1.4 squish is deliberately on the safe side on mine. I don't want to break anything unnecessarily! The thing with the squish is that i don't know if is so necessary to measure it, i start to think that Pinasco set the kit (that includes also the head and the crankshaft 60) already with the perfect squish... probably if i start to thicken the base in order to make it rev higher then the squish is important..but for a torquey kit like Pinasco maybe not? hmmm about the sealants... i was suggested to put the red silicon at the cylinder base together with the gasket...Pxguru suggested wd40 for the cylinder head but is it ok also for the cylinder base?
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modpx
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Post by modpx on Jan 6, 2013 18:39:55 GMT
Ok, let's try to put some order 1) Squish: A) This is the PMS of the piston into the cylinder, now, where do i have to put exactly the solder wire? cause once i slip the head on top of ithe cylinder, either i put the wire through the spark plug (that's one method i've heard) nor lay the wire on the piston head, the wire doesnt get squashed anywhere. B) In the second picture there's the base gasket i used when i made the engine, it's 0.25 mm like visible from the display in the picture. According to what parameters i have to choose which and how many gaskets to use? 2) In the third picture there's the seized spark plug. 3) If the blue paste is crap, how about red sylicon for warm temperature to seal? Attachments:
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modpx
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Post by modpx on Jan 6, 2013 18:39:06 GMT
You have to lose some mixture in the squish. Just keep it to the minimum. Which for yours with that head will be about 20cc I wouldn't advise for you or anyone to calculate it. If you get it wrong it will break a lot more than your piston! You must measure it. To get the most out of yours you need to decide how many base gaskets you need first. Your barrel must be at the correct height for maximum torque (47.5mm, top of stroke to top of main transfers). When you are ready to put it together put the piston on without the rings. Slip the barrel on with the base gaskets you will use. Get some solder wire and lay it on top of the piston (a cross of twisted wire works well). Put the head on an nip the nuts down (no need for tight). With the piston only going up, force it gently past the top, (only once). Take off the head and measure the squashed solder at the four ends. All should measure about the same. This is the squish, 1.2mm. Ok, let's try to put some order 1) Squish: A) This is the PMS of the piston into the cylinder, now, where do i have to put exactly the solder wire? cause once i slip the head on top of ithe cylinder, either i put the wire through the spark plug (that's one method i've heard) nor lay the wire on the piston head, the wire doesnt get squashed anywhere when i spin the flywheel and move the piston from down to up. B) In the second picture there's the base gasket i used when i made the engine, it's 0.25 mm like visible from the display in the picture. According to what parameters i have to choose which and how many gaskets to use? 2) In the third picture there's the seized spark plug. 3) If the blue paste is crap, how about red sylicon for warm temperature to seal? Attachments:
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modpx
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Post by modpx on Jan 6, 2013 18:38:06 GMT
You have to lose some mixture in the squish. Just keep it to the minimum. Which for yours with that head will be about 20cc I wouldn't advise for you or anyone to calculate it. If you get it wrong it will break a lot more than your piston! You must measure it. To get the most out of yours you need to decide how many base gaskets you need first. Your barrel must be at the correct height for maximum torque (47.5mm, top of stroke to top of main transfers). When you are ready to put it together put the piston on without the rings. Slip the barrel on with the base gaskets you will use. Get some solder wire and lay it on top of the piston (a cross of twisted wire works well). Put the head on an nip the nuts down (no need for tight). With the piston only going up, force it gently past the top, (only once). Take off the head and measure the squashed solder at the four ends. All should measure about the same. This is the squish, 1.2mm. Ok, let's try to put some order 1) Squish: A) This is the PMS of the piston into the cylinder, now, where do i have to put exactly the solder wire? cause once i slip the head on top of ithe cylinder, either i put the wire through the spark plug hole (that's one method i've heard) nor lay the wire on the piston head, the wire doesnt get squashed anywhere when i rotate the flywheel and move the piston up and down. B) In the second picture there's the base gasket i used when i made the engine, it's 0.25 mm like visible from the display in the picture. According to what parameters i have to choose which and how many gaskets to use? 2) In the third picture there's the seized spark plug. 3) If the blue paste is crap, how about red sylicon for warm temperature to seal? Attachments:
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modpx
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Post by modpx on Jan 5, 2013 15:58:21 GMT
ahahahhaha i see this is an old post ..but this one made me laugh! Saw them at Apollo Hammersmith in London in 2004 and they were still great! At one point Ron Wood joined the band on stage and they played "Stay with me" from the Faces. Brilliant! 10+
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Post by modpx on Jan 5, 2013 15:21:28 GMT
ahh by the way..what do you mean by "pinking" exactly? and where should i check those marks to verify if my settings are alright? Sorry for the too many questions..
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Post by modpx on Jan 5, 2013 15:13:12 GMT
If it's around the IT mark, it's definitely in the right area, but it's one of those things that can be a little trial and error in my experience - tuned engines are never perfectly the same by their very nature. But if the jetting is right (wrong kind of seize anyway) and there is no seal damage showing, then what else? Too small a squish band? I'm reaching the limits of my knowledge here, but my 207 is built on a 1.4mm squish, bang in the middle of the 1.2-1.6 I was advised to use. Nik, at 1.4mm your squish is a bit on the safe side. 1.2 is like the max really. Like Kru said your mates aren't paying for the repair and yours gave good advice erring on caution. If the squish is too tight it will cause pinking (and you will see the marks, when you take it apart to put a new piston in!). If it doesn't pink then its fine. When you are setting up a squish band it is worth remembering that the fuel compressed in the area of the squish band doesn't add any power to the stroke. A standard PX200 has a squish around 2.9mm (over double the max). How much of the 198cc is that?..........45cc of the uncompressed volume going straight out the pipe!! Just putting a 60mm crank in a totally standard PX200 with a standard base gasket (0.2mm) will up the squish to perfect at 1.2mm...funny that isn't it? And only loosing 18cc ;D So..you're saying that is possbile to calculate the squish approximately... and that a stock PX200 waists 45cc of its own power by using its original settings? and a PX200 with 60crackshaft has 1.2 squish and 1.2 squish is ok? hmmm so... a pinasco 60cranckshaft how much squish should have to be perfect? And how do i get there approx without calculating the PMS and the PMI (i dont know their names in english) and all that booring stuff? Could you simplify/clarify? Try to explain it like if you were explaing it to a kid.
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Post by modpx on Jan 5, 2013 8:20:17 GMT
Be careful with 'skilled mates' as they aren't paying your repair bills are they? ahahaha you're right but what d'you expect when you use 12 packs of beer for payment method! ;D ;D This time thou i guess was my fault since the problem was (most probably) in the carburation... When the new piston will arrive, i'll upgrade the jet to 135 and keep it richer, a bit of smoke and a black and oily spark plug is better than a seized cylinder after all.. thanks for the tips i'll keep you posted! Next thing to be tested, the new Megadella pipe for Pinasco!
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Post by modpx on Jan 4, 2013 20:37:53 GMT
On the IT mark sounds fine to me, Nik. The cold side seize mark looks bad enough to be a pinking seize but the piston crown doesn't have pits around the rim from what I can see. Maybe a picture of the head (from the business side!) would confirm it. Hello guys, well, i polished the cylinder, i first sandpaper it with water sandpaper 1200 then i polished it...the visual marks are still there, actually there´s a little scratch that i can feel with the fingertip but nothin major it´s really little, the piston... well i decided to buy a new one i found one including shipping bills for 108€ not bad... it´s useless to recicle the old. the performance will go down and i love too much the kick of my pinasco to give it up like this. This is the head, looks ok to me. About the squish i dont know ... my knowledge is limited to plug and play, when it comes to work the cases match the ports or more "tecnical" things i usually pass it to more skilled mates ;D Attachments:
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Post by modpx on Jan 3, 2013 20:39:15 GMT
Definately a hot seize. I'd guess the timing is set at standard from that damage.. how can I put this... 'It looks familiar!' Over sized pistons are made by the same manufacturer - you generally find them in stepped increments. buy the next size up, check what the tolerances are and give the piston, cylinder and tolerances to a machine shop to do the work. If it'll polish up, then I'd get a new standard piston. That one is definately past its use by date. No the timing is set almost on IT... im trying to figure out what that might depend on... if it was intaking air from somewhere should´ve shown some signs like "accelerated idle" or something... i see that the pinasco piston rings are 1 standard and 1 extra, do you know the measures? cause i have 1 pinasco (the lower) that is ok and 2 piaggio 66,5mm that are new..would it be possible to mix them or it´s insane?
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Post by modpx on Jan 3, 2013 10:22:24 GMT
Here's my new pipe, it goes really well especially at lower range, gives a great kick and has an supercool sound. Top speed so far 123 km (odometer, not gps) with me on top 115kg.
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Post by modpx on Jan 3, 2013 10:17:56 GMT
Its always a bit gutting on a new bore. 2013 might be your lucky year, as it looks like you got away with it Only the top 2cm of the bore ever need to be fully score free. It might look awful but it will run fine after a clean up. If it was mine I would get some 600 grit wet and dry paper and rub out the worst of the bruise in the barrel (careful!) and the same on the piston (less careful). The ring groves on the piston have burred slightly, so clean those out. If you get the rings off without breaking them they will go back ok too. Check the piston for tiny cracks. If ok I would put it back in! I doubt the barrel liner is cracked but if it is...... Now the important bit. Why did it seize? Assuming you weren't wringing it's neck. I think you were very lucky. This is is exactly the type of seize I was talking about in the post "Running In". It is called a "lean seize", recognisable from all the other types by a big bruise near the exhaust port and a small complementary bruise on the opposite side of the piston. It is caused by the main jet being too small (rule of thumb; if it heat seizes on an SI carb the main jet is at least 10 points too small). If you really don't know how to jet in a 2 stroke just ask any of us on here Don't forget to set your barrel height to exactly suit your engine when you re-assemble it (re- Which pipe on a Pinasco 225?) Hi, i show you also the other side of the piston that is what makes me think that the piston is gone, there's that crack in between the ports in the lower side, well that you can catch a nail on...i'll definitely try to clean the cylinder upplike you said then. Ii'm very interested in knowing the cause too since i wouldnt like this to happen again. I can't diagnose exactly so any help is very appreciated. What i can certainly do is upjetting the carb indeed that i actually took up to 132. Here''s a video of the pipe just mounted after a little a ride i took to test the spark plug. I also post it in the "which pipe on a 225" to complete the post. Well it was super "rich", all black and oily. So i screwed in the screw under the carburetor to make it poorer. Yesterday i wanted to take a longer ride and test it again but...it was probably too long... Attachments:
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Post by modpx on Jan 3, 2013 1:00:49 GMT
Well if that 'damage' on the bore could be honed out (as you say it's more visual than actual damage) then you'd get away fitting whatever size this nipped up piston was (std?) I'd reckon. Think I'd chance it provided the hone removed the 'damage/scuff'. It has picked up on that now scrap piston, but not scored the bore by the looks of it. Score = rebore at least. Is there any chance i can just polish out the cylinder without taking it to rebore? And if yes, what's the procedure for a home made polish?
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modpx
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Post by modpx on Jan 3, 2013 0:13:21 GMT
Can you find an oversize piston for it? Looks like nothing that isn't recoverable with a rebore. It may even polish out with a quick hone. As a rough rule of thumb, if you can catch a nail on the damage, then it's too far gone to reuse as is, but a rebore will often recover the barrel. Pistons fukked though... Hi thanks for the tips! The rectangle shaped stain that you see under the cylinder ports is flat, smooth as well as the rest of the cylinder, there are some scratches of course but nothing you can catch a nail on could you make me an example of oversize piston that would fit my purposes? I maybe found a used pinasco piston but the guy doesnt have the pinasco rings (which are quite expensive, 45€ from Sip) I have two brand newpiston rings for the original px200 piaggio piston instead, would they fit into the Pinasco piston? Is the quality approx the same? thanks
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Post by modpx on Jan 2, 2013 21:17:26 GMT
Hello guys, i took a ride on my kitted 225 PX yesterday, JL pipe freshly mounted..and after 20km this was the result... now besides the causes (air intake from the cylinder head?, troo tight carburator screw? Damaged mixer..?) what i'd like to know is if in your opinion the cylinder can be saved..i dont have much of hope in the piston... Attachments:
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Post by modpx on Jan 2, 2013 21:14:45 GMT
Hello guys, i took a ride on my kitted 225 PX yesterday, JL pipe freshly mounted..and after 20km this was the result... now besides the causes (air intake from the cylinder head?, troo tight carburator screw? Damaged mixer..?) what i'd like to know is if in your opinion the cylinder can be saved..i dont have much of hope in the piston... Attachments:
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Post by modpx on Jan 2, 2013 21:13:34 GMT
Hello guys, i took a ride on my kitted 225 PX yesterday, JL pipe freshly mounted..and after 20km this was the result... now besides the causes (air intake from the cylinder head?, troo tight carburator screw? Damaged mixer..?) what i'd like to know is if in your opinion the cylinder can be saved..i dont have much of hope in the piston... Attachments:
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Post by modpx on Dec 23, 2012 22:10:40 GMT
Like the idea of wheelies in every gear! And sounds like you are almost there but if you still have a gap between 3rd and 4th (36tooth) I'm sorry but it just isn't set up right. At the top end of tuning 2 strokes every 0.1 of a mm counts. Guys can't just bolt stuff on out of the box and expect maximum performance. Sometimes people get lucky with the tolerances but by measuring and adjusting a few things to suit your engine there is no luck involved. I calculated for your set up you need to have at least the following two important things right; 1. The top edge of your main transfer ports should be no more than 47.5mm down from where your piston is at the top of stroke (TDC). Use a feeler gauge to measure the minus deck and vernier from the deck to the port roof. After adjusting the barrel to get the ports at the right height, then; 2. Compression should be over 10.5:1 but not more than 11:1. Measure carefully with a syringe, some oil and a calculator. Less than 10.5:1 and it won't have full torque, more than 11:1 it won't have max power. I know I go on a bit but sometimes I have a point btw. For this set up just use the exhaust you like the sound of. Pinasco are one of my old favorites! Hi Guru thanks for the explanation, there´s a misunderstanding though, it´s just cause i put the short 4th 36 that i solved the- gap between 3rd and 4rth-problem. i also add the long third gear by DRT, reinforced the primary gear and the clutch BUT no calculation of the compression and the top edge of the main transfer ports. I see you vote for the Pinasco pipe as well... Could JL Righthand create a super torquey monster combined with my set up?? Some say I could carry a tractor with that..
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Post by modpx on Dec 23, 2012 0:34:26 GMT
The topic interested me so I had a scan. Can't find much but found this on another site............. so ? "I ran a Zirri pipe on a highly tuned P125 a ways back and did not like it much, not so much because of performance but because of build quality. This was back in the late '90s though, so depending on when your pipe was produced it may have better construction. Basically since it was a solid mount it kept ripping through the metal near the bracket. I kept having to get it welded and eventually gave up, going back to an MSC Micron (remember those!) that had its own mounting issues. Also it was pretty loud as it had a very basic silencer only". The Zirri i got is brand new, 0.8 mm, build appositely for me(it took 2 months to Angelo Zirri before the delivery) and has a great quality. only problem is i bought it when i didn't have Pinasco in mind. ..what is making me doubt about it is the fact that is considered very good for very high performance cilinders which rev very high (Zirri, Quattrini, PArmakit) and many are suggesting me not to put it under my Pinasco. Do you remember which kit your mate had on his P125? It's loud yes, but im not shy Attachments:
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modpx
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Post by modpx on Dec 22, 2012 21:37:48 GMT
A mate has pinasco kit and pinasco exhaust, it's a great set up, he has toured all over europe with no problems and gets better fuel consumption than standard P2 s. Yeah Pinasco pipe with Pinasco kit..i dont know why it's such an underrated combination... not much people uses it neither in Italy nor in northern europe. myself never tryed a chrome pinasco pipe although i have to admit it looks really cool ;D thanks for the tip, i'll investigate...
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modpx
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Post by modpx on Dec 22, 2012 21:29:54 GMT
Modpx, I'm a little upset. Why you put a T5 4th in a Pinasco? And you have a 60mm crank too!! If you cant pull a 35 tooth with that kit and crank......its not set up right. If you put a 30mm carb on it too you should will be thinking about a 34 tooth 4th to cruise faster. The Pinasco has the most torque of all the kits. Many of the kits come with low compression heads so it might not be all your fault but you should have measured everything when you were putting it together. A pinasco doesn't have the ports to be a 9000 rpm screamer! I'm happy to help if you want to sort it out. Thank you very much for your answer, i matched the port at the base of the cilinder, the head (original pinasco included in the kit) has a very good compression. I chose the short fourth to cancel the "gap" between the third and fourth gear that i find pretty annoying, also because with shorter transmission the Vespa with this Kit wheelies in every gear! I have the Sì 24 carb which is perfect for touring..what i was searching from this set up is something between a street racer and a fast tourer... thats why it probably looks a bit "illogical". The top speed is a bit lower with this set up but the vespa is super torquey and it still reaches a good enough top speed. I cant try it yet ont he road cause here in scandinavia where i live at the moment roads are full covered in ice and snow..so im taking my time to work on the adjustments.. Sorry for my english, it's not very good what comes engine parts and techincal language.
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modpx
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Post by modpx on Dec 22, 2012 21:10:31 GMT
The topic interested me so I had a scan. Can't find much but found this on another site............. so ? "I ran a Zirri pipe on a highly tuned P125 a ways back and did not like it much, not so much because of performance but because of build quality. This was back in the late '90s though, so depending on when your pipe was produced it may have better construction. Basically since it was a solid mount it kept ripping through the metal near the bracket. I kept having to get it welded and eventually gave up, going back to an MSC Micron (remember those!) that had its own mounting issues. Also it was pretty loud as it had a very basic silencer only". The Zirri i got is brand new, 0.8 mm, build appositely for me(it took 2 months to Angelo Zirri before the delivery) and has a great quality. only problem is i bought it when i didn't have Pinasco in mind. ..what is making me doubt about it is the fact that is considered very good for very high performance cilinders which rev very high (Zirri, Quattrini, PArmakit) and many are suggesting me not to put it under my Pinasco. Do you remember which kit your mate had on his P125? It's loud yes, but im not shy
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modpx
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Post by modpx on Dec 21, 2012 23:01:07 GMT
If it's low down grunt, and you're not looking for a race type (and looks) pipe, why not try a SIP Street, or Broady's now one when it comes out? Pinasco it's a touring torquey cylinder but i wouldnt like to put a Sip road, i was trying to find something more racing, i drilled the air filter and put the short 4rth gear 36 teeth (from DRT) in order to get higher revs... How about a Zirri? Do you know that pipe? Any other suggestion?
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modpx
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Post by modpx on Dec 21, 2012 9:49:43 GMT
Hello everyone, which pipe you put under a Pinasco long stroke 225? Pinasco is considered a low-revs cilynder which doesnt work well with high revs pipes.. Any suggestion? I own a Zirri for PX200 at the moment that i havent mounted yet.
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Hello!
Dec 21, 2012 9:31:32 GMT
Post by modpx on Dec 21, 2012 9:31:32 GMT
I'm a italian scooterist, i owned a Vespa PX200 for three years now. I live in Scandinavia where i attend to rallies and rideouts with my scooter club. I joined this forum cause i think it's always good to share opinions and ideas with other scooterists from other countries. Attachments:
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