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Post by jid1973 on May 22, 2014 9:26:59 GMT
Hello all.
I'm sure this has been asked many times.
I have a px125 and will be replacing the engine for a standard px200 (elec start and Autolube)
My question is which would be the best performance exhaust to fit to the 200 lump and what are the benefits.
Thank you
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Post by vespasco on May 22, 2014 17:30:03 GMT
Sip road
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Post by partanen on May 22, 2014 17:32:52 GMT
Sip Road 2.0  |
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Post by vespasco on May 22, 2014 17:33:43 GMT
Hahaha!
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Post by pxguru on May 22, 2014 17:44:40 GMT
Is it a totally standard PX200 engine? And are you planning on keeping it that way?
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Post by sbwnik on May 22, 2014 18:11:40 GMT
SIP Road 2
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Post by jid1973 on May 22, 2014 18:22:44 GMT
Yes standard. Yes to keeping it that way.
SIP all the way then
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Post by partanen on May 22, 2014 18:47:16 GMT
Sip Road 2.0 is a tad louder than genuine pipe. But the sound is close to original. For sure works great. Better use bigger jet though. I have 122 at the moment. I have tried 125, but I'm not sure which is better, yet.
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Post by henri on May 22, 2014 19:38:30 GMT
have just bought a sip road 2 for fitting on mates px200 in standard tune ,local piaggio dealer an shop i bought from both told me 118 for the main .reckoned it would get me in the ballpark ,but ya post seems to indicate it would be a tad lean .the scoot is used for daily city riding an a dual carriageway 10 mile each way commute.so does get some full throttle action in both roles,but more sustained on the commute obviously,damm green council an there 20mph speed limit an other car hating policys. might have to buy a jet set i guess an work down from 122-125 . anybody else got a suggestion ,only put em on 125/150's before . h
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Post by jid1973 on May 22, 2014 19:54:19 GMT
Do you get much more speed?
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Post by partanen on May 22, 2014 20:01:14 GMT
These newer ones had 116 main jet. Add 5% more, it would be 121,8. To be on safer side I tried 125. Trying to find correct ignition timing at the same time and that's why I'm still pondering between those two.
I had more oomph at some point, but then I reduced ignition timing to "IT".
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Post by sbwnik on May 22, 2014 20:26:16 GMT
SIP say timing to 18 degrees. I run a 125 in mine as I've also got the airfilter drilled, but it does feel marginally rich.
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Post by partanen on May 22, 2014 20:41:55 GMT
As we have a quite warm weather at the moment 122 feels a bit too rich. Then again we do not have 26 celsius every day. And this damn 5% ethanol, which ruins everything normal.
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Post by pxguru on May 23, 2014 5:48:47 GMT
As we have a quite warm weather at the moment 122 feels a bit too rich. Then again we do not have 26 celsius every day. And this damn 5% ethanol, which ruins everything normal. The SIP ROAD 2.0 is the best there is for any standard. I normally find that when you can actually "feel" it is rich it is often two jet sizes too big. One jet size bigger than it needs is usually enough safety margin for weather changes. |
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Post by henri on May 23, 2014 7:05:39 GMT
after the post last night couldnt get to sleep as it didnt sound right ,so got up an dug out the "haynes book of lies" ,an a later auto-lube runs on a 118main as standard ,the shops must of misunderstood what i was asking,did the math (expansion pipe an free flow filter=up 10%) just a sip an drilled filter =122-124 , +5% ,an that seems to match what you guys are running .as its standard tune+30,000miles thinking a 124 an leave it in year round an not worry about weather/pressure/humidity.
its my mates daily hack an he's just looking for a little more top-end cruiseing for his commute an doesnt want scoot off road for any time tuning/fixing.he's a bit of a magpie an had to be talked out of a st/steel expansion pipe, lurves that shiny but never washes his px,but as its in grey primer an lacquer looks good like that. 124 in,an 122 on shelf,my spidey senses are tingling an i sense a "chopping" session in my near future. Henri
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Post by pxguru on May 23, 2014 9:11:23 GMT
I think the "haynes book of lies" is true to its word. The old P200E had the 118 main jet and the PX200 autolube has a 116, as the 2 stroke oil isn't pre mixed and going through the main jet it can then be a size smaller. btw. To avoid anyone trawling the internet to find some "hen's teeth", I have never seen an SI 124 main jet (116, 118, 120, 122, 125, 128 etc.) To get all the hole picking out of the way in one post. If you have a standard 200 barrel and standard 200 head with the 3mm squish, the timing stays at 23 degrees on the A mark. If you retard the timing it will go fine, nearly the same but will feel a bit sluggish low down, drink more fuel and increase EGT. Ok rant over  |
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Post by jid1973 on May 23, 2014 10:39:09 GMT
Would I got more top end out of the SIP than standard then. Do you know roughly how much?
And general consensus is to go with a bigger main jet. Somewhere around 122-125
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Post by jid1973 on May 23, 2014 10:39:56 GMT
A friend has mentioned about the BGM pro exhaust. Any thoughts?
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Post by sbwnik on May 23, 2014 19:51:04 GMT
Yes on a tuned motor, no on a standard.
I think we've discussed this somewhere else on here recently, and it's more than a little suspicious that MRB have only released dyno graphs showing them trouncing the competition when fitted to a kitted engine.
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Post by sbwnik on May 23, 2014 19:54:40 GMT
To get all the hole picking out of the way in one post. If you have a standard 200 barrel and standard 200 head with the 3mm squish, the timing stays at 23 degrees on the A mark. If you retard the timing it will go fine, nearly the same but will feel a bit sluggish low down, drink more fuel and increase EGT. Ok rant over Run a SIP pipe at 23 and you'll hole the piston. I found that out the expensive way - three pistons in the first year - but not one since. The advice is on SIPs website. And it doesn't feel sluggish low down, I've been riding an identical scooter with a Sterling on this week... THAT feels sluggish low down, and in the mid range. Horrible to ride! |
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Post by partanen on May 23, 2014 20:30:17 GMT
To get all the hole picking out of the way in one post. If you have a standard 200 barrel and standard 200 head with the 3mm squish, the timing stays at 23 degrees on the A mark. If you retard the timing it will go fine, nearly the same but will feel a bit sluggish low down, drink more fuel and increase EGT. Ok rant over Run a SIP pipe at 23 and you'll hole the piston. I found that out the expensive way - three pistons in the first year - but not one since. The advice is on SIPs website. How about bigger main jet? It should cool down the combustion temperature. |
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Post by jid1973 on May 24, 2014 11:38:43 GMT
Thanks all for the comments and advice.
I'm getting a friend to fit the engine and the SIP is on the way with a couple of main jets.
Everything else is standard on the bike.
From reading the threads people are dating to adjust the timing.
What do you think about that.
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Post by partanen on May 26, 2014 8:50:16 GMT
Throttle slide without air pocket would be a good choice to be on safer side. I just put one in and I can say throttle response is better now, at partial throttle.
Is the slide with air pocket installed only for these later models?
I'd still like to know if holed piston can be prevent by giving more fuel. Richer mixture should give cooler combustion temperatures.
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Post by sbwnik on May 26, 2014 19:01:29 GMT
Mine was running a 125 when it popped the pistons. It's still running one now.
SIP recommend a 122.
No harm in experimenting though.
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Post by vespasco on May 26, 2014 22:03:42 GMT
Cooling the combustion temperature would be a great help, as it is heat build up that would cause things like, for eg, niks 3 x holed pistons. Pre ignition was the likely cause.
But what made it pre ignite?!
If the engine was running spot-on before the sip road was fitted and the jets/mix were changed accordingly, then the only other cause would be the (advanced) timing, causing it to pre ignite.
A larger main jet would have helped a little but it would only be masking the real problem (too advanced timing).
Too hot plug, carbon build up, lean mix, high compression, too much oil etc are other factors that could lead to pre ignition.
So i believe a richer mix (not more fuel) could aid the battle to stop holing a piston (pre-ignition) but not necessarily cure it.
There are lots of factors to take into consideration but im relying on the fact that engine was running perfectly before any mods were done.
Using a higher octane/ premium petrol can also help. Especially if you use a higher compression head for example. Plus the fact higher octane fuel does not contain as much ethanol as premium also should now be taken into account these days. This has been discussed recently.
Retarding the ignition (making the spark plug fire closer/later to tdc) minimizs the chances of early/pre ignition
The rally slides had no 'air pockets'.
I experimented with slides wirh various cut aways etc and found they had quite an effect over 1/4 - 1/2 throttle range.
(I now use the one with the 2 x kidney shaped (No. 4)? air pockets on my kitted motor to give smoothest progressional period).
So yes, timing, along with jetting, should be adjusted, generally retarded / richer, for any 'tuning' modification, especially if you're fitting an expansion pipe.
Even switching fuel from standard to premium would effect the combustion process and as such may need timing adjustments.
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