Px 200

[mickbr71]

Recently fried my polini 208 so toying with the idea of running a standard top end , only prob is I have a reed valve and 28mm carb . Any ideas where I would start on jetting ? Cheers

[vespasco]

if you still want that little extra than a stock 200 gives, try an ali kit... the new polini, malossi etc

and find out why your polini seized (if thats what's happened) im only guessing its an older cast iron cylinder?

post some pics of your piston and cylinder if you're not sure what to look for.

i could not be sure how a stock cylinder would run with a 28mm/ reed valve but there are ways, if your mad enough...... you know who you are

[mickbr71]

Yep it was a steel one and the piston was a right mess , not sure how to put pics on here. As for why I'm not sure it's been fine up till now , 124 main jet with a good plug colour .

[vespasco]

well its not your auto lube then
but could have been a number of things that caused it to heat seize (?)
air leak, too lean - heat seize..?
im not sure how you would go about converting back to using an SI carb
does the crank still turn freely?

are the cases ported to match the polini?
if so, a new ali polini maybe be a good choice??

[mickbr71]

No autolube , premix only Definate heatseize caught it on the clutch but stupidly slowed down and carried on rather than stopping . Casings ported crank etc all still ok

[pxguru]

To post pictures create an account at photobucket.com and post the link here. There are some more detailed instructions somewhere.

Unlucky but not a disaster. One of mine started as an iron Polini. Whatever you do, don't buy a new Polini piston! If you want to run it again and the bore is a mess get it rebored to fit a Malossi 210 Piston. No need to mess about porting it, if you don't want to. Will just go better with the Malossi piston fitted.

It would have siezed up because there was something wrong with the jetting/needle/atomiser/pilot. Doesn't need to be much. Get it right they run forever, slightly wrong and they heat seize. Ignition timing is not so important on these, in standard form they run with nearly anything, just need the jetting to be good at all rpm and all throttle positions.

[mickbr71]

Thanks .3 options either malossi 210, polini 210 which are both alloy and expensive if I get it wrong ,or just sling and standard top end on with the sip road 2 and down jet the 28 mm dellorto ,

[pxguru]

Not sure you fully understood. Keep the Polini barrel you have but put a Malossi piston in it. Still not so cheap though. A Malossi piston and rebore for the old barrel will be about 120 quid. Might be able to get something used off ebay. Anything is better than a standard 200 barrel.

[henri]

as pxguru says , if ya stick a stock barrel on you'll hate it after the polini , re-bore an grand-sport .de piston would be my choice .H

[mickbr71]

So update time , since i last posted ive fitted a alloy polini 210 ,
DRT fast flow 24m si carb with one of these  www.ebay.co.uk/itm/VESPA-VERGASER-Membran-SI-Motor-PX-80-125-200-Sprint-Rally-GL-GT-VBB-VNB-GS-4-SS-/192108772087?hash=item2cba933af7:m:mJGcCZ5POv-PQrR1213L8pw

Sip road 2 pipe 
Sip touring lighted flywheel
BGM  fast flow tap 

Depsite playing with various jetting options it still runs lean , no air leaks
ive tried standard pilot jet 55/160 with 160 a/c,
50/140 with 140 a/c
52/140 with 140 a/c and 160 a/c
All of the above have been with a BE3 atomizer and mj ranging from 140 up to 150 .  
 
so whats next ? it runs/pulls well but cant get the plug a nice colour  

Any ideas appreciated  

[pxguru]

The Polini 210 is a good solid kit. Did you get the head too. Why did you change the 28mm and reeds for this LML type reed and Si24? Must be some good reason. And it's not to run autolube with that block in the way.

Now you have this set up the first thing you need to do is drill the carb. At least 1.8mm is required for a 210. We have drilled ours to 2.0mm and seems to be ok. The standard drilling will struggle to supply much more than a 140MJ.
Once you get it to run black on a 150MJ then start jetting in.

have a look at these tips for some ideas

[mijapxman]

Please look at this, first!!!
 
Also have a look on the modern vespa forum/ not so modern section. A Scottish guy on it runs a p210malossi with one of those reeds, search " case preparation for reed? " the Scottish guy is Nebulae, their is a link to him on  that thread.


I also have one of those reeds on a 200 engine, but not fitted it in frame yet, have fitted one to a  mildly tuned DR177 ,  standard crank, 24/24mm with sip exhaust and it went well. They fit mark1 PX cases but my mate fitted one to a t5 and he had to get welding done to the case where it sits!! May be the same on PX oil injection cases??? Not sure?
  
For what it's worth, If it was my engine, I think I would use the big reed valve and carb.

So two different options.
  All the best 

[mickbr71]

Mar 14, 2017 13:14:20 GMT pxguru said:

The Polini 210 is a good solid kit. Did you get the head too. Why did you change the 28mm and reeds for this LML type reed and Si24? Must be some good reason. And it's not to run autolube with that block in the way.

Now you have this set up the first thing you need to do is drill the carb. At least 1.8mm is required for a 210. We have drilled ours to 2.0mm and seems to be ok. The standard drilling will struggle to supply much more than a 140MJ.
Once you get it to run black on a 150MJ then start jetting in.

have a look at these tips for some ideas

Got rid of reed valve and 28mm mainly to improve the mpgs and to calm the revs down  . The carb is already drilled ,i got a drt modified one from sip so should be ok . the head is also from sip modified for that kit . will try the 150 mj and go from there

cheers Mick 

[mickbr71]

Mar 14, 2017 15:44:54 GMT mijapxman said:

Please look at this, first!!!
 
Also have a look on the modern vespa forum/ not so modern section. A Scottish guy on it runs a p210malossi with one of those reeds, search " case preparation for reed? " the Scottish guy is Nebulae, their is a link to him on  that thread.


I also have one of those reeds on a 200 engine, but not fitted it in frame yet, have fitted one to a  mildly tuned DR177 ,  standard crank, 24/24mm with sip exhaust and it went well. They fit mark1 PX cases but my mate fitted one to a t5 and he had to get welding done to the case where it sits!! May be the same on PX oil injection cases??? Not sure?
  
For what it's worth, If it was my engine, I think I would use the big reed valve and carb.

So two different options.
  All the best 

Cheers ive seen that post before but never had the fitting issue he had ,my was a straight fit. Will have a look at the video later and start again 
cheers Mick

[pxguru]

Should be no problem with the DRT carb. All the mods should be done to it. If you haven't already check the flow out of your tank is enough, like in the videos.

Check the overflow out of the carb float bowl is not blocked or obstructed by your flat reed block (fuel doesn't go in if air can't get out)

What is on top of your carb, Vortex, filter or nothing? And is the carb box connected by rubber hose to the frame?

Start with a 55/160 BE3, AC160 and 150MJ and see how it runs. Should be spluttery and smoking way too much.

[mickbr71]

So stripped her down and noticed the Conrod has been rubbing on the crank web , so guessing it's new crank time . Which one though full circle of bell shaped ?

[pxguru]

Conrod rubbing on the crank?? Thats weird. Has the clutch nut come loose, big end gone wobbly or main bearing worn out?
Bell shaped for high rpm screaming tuned engines and full circle for normal people

[mickbr71]

Here it is , see mark on conrod

[pxguru]

Not ideal is it? Crank doesn't look so old. How loose is the big end bearing?

The mark is the wrong side for main bearing or loose clutch nut but it does look like the big end pin is sticking out too far. Might have been damaged in the last seize.

To save the cost of a new crank. If the crank is in otherwise good condition, you could get it pressed out and straightened or just fit these while you are at it.
www.sip-scootershop.com/en/products/crankshaft+pin+drt+eccentric_4043ad179 & www.sip-scootershop.com/en/products/conrod+kit+mazzucchelli+for_bco0502m
But this is probably easier, although more cost overall
www.sip-scootershop.com/en/products/full+circle+crankshaft+mazzu_45040000

[mickbr71]

Bearing seems ok tbh but something isnt right, Im Thinking im going to go with the full circle mazzucchelli a - because its easier and B- once its done it done and will be better suited to the reed valve . Im also going to open the inlet more to match the reed set up and ditching the kit and going back to a standard top end just need to decide if i go 57 or 60 stroke

[mickbr71]

Ok change of plan maybe what would be the advantage of a flowed crank rather than full circle or bell ?

[mijapxman]

Maybe have another look at the threads on modern vespa, not so modern, ' case preparation for reed?' I posted, they also talk about cranks, tho pxgurus advice is good as always 😀.

I opened the inlet on the 2 I've be done to match the reed gasket (Max)

The thing that concerns me on my ' O' tuned 200 engine is using this reed, which is similar to an LML reed,

 it may be as hard to jet as Mr freek moped found tuning an LML engine , so I may end up going big reed, big carb!, and 210 kit!, but being skint, I

think , If I can' t get the 'o' tune to jet properly, the next thing I'll try is my spare 200 barrel with the exhaust port ported the same as scooterotica do, as I posted on the site before.

Was wondering, did you have the same problem as nebulae and I fitting the engine to the frame after fitting the reed?


All the best J.☺☺☺

[mickbr71]

No i didnt have the same problem as nebulae did when fitting the reed , if i remember correctly he was using rally 200 casings so maybe there is a slight difference between that and a PX200 block . Jetting maybe be a issue but i guess it will be trial and error as usual . Still unsure if im going to go long stroke or stay with 57 , im interested in the scooteroctica exhaust porting but cant find it on there .

[mickbr71]

So opened inlet up more so it matches the reed setup better , could go sme more but think that will be enough as this is the first time ive done it and dont want to go to far and go through the casing .

[pxguru]

To run a standard barrel any crank will do. 60mm crank will make it go better and an exhaust tweek with a base packer and even better still. Gas flowing cranks and inlet port size are not going to be any benefit with those tiny little transfer ports in the standard barrel.

My tourer is 'O' tuned standard barrel but my way of doing it. 22 bhp on the last test. And still needs a slight head skim and a Carb Vortex before its finished.

That mark on the conrod is no issue yet. I would take the crank out and get it re-pressed and checked over at some workshop. What else will you do with the crank, bin it? I would carry on with the 208 too, will run forever set up properly

[mickbr71]

Mar 24, 2017 6:12:16 GMT pxguru said:

To run a standard barrel any crank will do. 60mm crank will make it go better and an exhaust tweek with a base packer and even better still. Gas flowing cranks and inlet port size are not going to be any benefit with those tiny little transfer ports in the standard barrel.

My tourer is 'O' tuned standard barrel but my way of doing it. 22 bhp on the last test. And still needs a slight head skim and a Carb Vortex before its finished.

That mark on the conrod is no issue yet. I would take the crank out and get it re-pressed and checked over at some workshop. What else will you do with the crank, bin it? I would carry on with the 208 too, will run forever set up properly

forgive me for being dumb but what is O tuned ? 22 bhp ? thats impressive  how ?

Agree port sizes etc are not beneficial but the work is done if i decide to go back to the 208 or even the 210 at a later date.

cheers   

[mijapxman]

The first reed I fitted to a mrk1 p125x case and had to alter the shock to get it to fit the frame, glad you didn't have that prob mickbr71😊
Will repost the scooterotica exhaust tune later, as I have a Doctors appointment at 5pm today.

[mickbr71]

It was tight but there is just enough room to get the carb top off , cheers that would be great 👍

[mijapxman]

Doc sent me for an urgent chest xray ! Would have been a 15 mile round trip to nearest hospital but no xrays after 4 pm at that one,

, had to go on a 45 mile round trip to the next nearest one that does xrays till 8pm!

Just home, black lab and Scottie dog to walk now, then a hunt for the scooterotica porting link when I get back in. 😉😉😁

[mijapxman]

And.......
I'm back in the room.😂😂😂

This is what Scooterotica garage wrote

The standard exhaust port on a p200 is approx 39mm wide ( when measured straight across) we only took it

out 1.5 mm each side (3mm in total) but it had a fantastic effect on the engines characteristics. Slightly

improved revs= more power! but with minimal effect on reliability and although we didn't raise the overall

Height of the exhaust port ( as this kills bottom end ) we did slightly raise the side edges at the top of

the port ( 1mm on each side ) so that the top of the port at each side was closer to the overall height of

the port in the centre ( it is an oval shaped port ).


'O' tuning , is tuning to a standard barrel, Google,  vespa p200 O tuning and see what hits you get, if you want to know more, bud ☺☺


When I was doing my motor, I was kind of trying to cover any future tuning and porting, by porting the case accordingly, in the hope I wouldn't need to do any more inlet porting if I went


big reed, big carb.


If you haven' t yet had a read of the PX200 Tourer thread that pxguru has on page 2 of the technical discussions part of this forum, I highly recommend that you do! ☺ 


I think of him as my Vespa Sifu