Stella 2T exhaust upgrade suggestions

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Mike Zero
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Stella 2T exhaust upgrade suggestions

Post by Mike Zero »

Sorry if this topic has been already been discussed but I would like to upgrade from the stock exhaust and I have no clue what would be a good option. What would you guys recommend and what kind of work will be involved with installing a new exhaust?

Thanks!
fisher1
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Post by fisher1 »

Regardless which option you choose, first install the CHT and then benchmark / record the stock temps at various riding conditions including sustained road stretches at @35mph-1/2 throttle, Wide Open Throttle, etc. Write them down for future reference.

After you install your new exhaust and filter, rejet to somewhat duplicate the stock temps at the various road conditions as well as plug readings. Don't think the rejetting is limited to the main jet. My midrange running temps shot up dramatically and I had to change the SI/pilot from the stock 55/160 (2.9) jet to a richer 52/140 (2.7). (Note that larger SI#s are leaner.)
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jimmbomb
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Post by jimmbomb »

I always liked the 226 Vintage Hotwing pipe, and modded air filter, then a rejet.
it isnt difficult to remove and replace the exhaust IF you're handy with wrenchs and stuff.
.
2 bolts and your stock pipe is off the bike.
Some folks have to remove the rear wheel to get the bottom bolt out, but i just let the air out of the tire.

fisher 1. . Please pardon my momentary threadjack...
where do you get your CHT's from and do they require external 12 volt power... or a r e they self powered.
thanks..
J H
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BuddyRaton
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Post by BuddyRaton »

The first question to ask before any mods is what do you want to get out of it? Acceleration? torque? higher top end?

Fisher makes a good point. I don't run any modified motor without at a minimum a CHT. Highly modified I run CHT EGT and tach.

I use 2 types of CHTs

The Westach does not need any power. I also use a SIP speedo SIP on a kitted P200 which is powered
"Things fall apart - it's scientific" - David Byrne
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'06 Cream Buddy 125, 11 Blur 220, 13 BMW C 650 GT, 68 Vespa SS180, 64 Vespa GS MK II, 65 Lambretta TV 175, 67 Vespa GT, 64 Vespa 150 VBB 64 Vespa GL
fisher1
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Post by fisher1 »

From:
topic29150.html
This is inexpensive and easy easy to install. It "toggles" back and forth between showing your real-time Head-Temp and the Max Head-Temp of your current trip. The "Max" temp resets when the current head temp drops below @130 degrees - so it always shows the Max of the current trip, not past ones.

TTO Temp Meter - Silver - 14mm Spark Plug Sensor

http://www.trailtech.net/72-et3

Temp. sensor extension lead (24 inch long)

http://www.trailtech.net/temp-sensor-ex ... -inch-long

A stock Stella will usually show a max @ 295F-310F at extended wide open throttle. My CHT saved me when my scoot developed an air leak between the exhaust and the cylinder stub, max temps had shot up 40 degrees. I tightened the exhaust clamp before it got worse, and temps restored back to normal next time out.
This has it's own battery that lasts a long time, I've never replaced mine. I did use a dremel to slightly increase the 14mm hole size to make it easier to put on the plug. Also cut a "notch" in the plastic heat shoud's plug hole to allow the wire to follow out next to the plug.

I agree with other posters that 1) first install a CHT, 2) if you change an exhaust and filter - do it with a goal in mind (serious performance, or simply to remove the Stella restrictions and replicate the PX150, or whatever) and 3) if you do anything other than going with the PX150 exhaust/filter for reasonable improvement, then an EGT is beneficial - and can't hurt in any case. 4) Rely on your own plug & temp checks, not on simply what people advise because each scoot/exhaust/filter my have different needs.

If you only want moderate performance improvement by removing the Stella restrictive exhaust and filter, then a replacement PX150 exhaust and filter will do that. But you will still need to fatten your SI pilot and Main jets as a result.

Also note that the increased ethanol in gas has perhaps made some of the older recommendations a bit lean anyways. Your plug checks and CHT or EGT will show you that. I'm no expert, listen to the others who post who have a lot more experience than me.
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jimmbomb
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Post by jimmbomb »

fisher1 wrote:From:
topic29150.html
This is inexpensive and easy easy to install. It "toggles" back and forth between showing your real-time Head-Temp and the Max Head-Temp of your current trip. The "Max" temp resets when the current head temp drops below @130 degrees - so it always shows the Max of the current trip, not past ones.

TTO Temp Meter - Silver - 14mm Spark Plug Sensor

http://www.trailtech.net/72-et3

Temp. sensor extension lead (24 inch long)

http://www.trailtech.net/temp-sensor-ex ... -inch-long

A stock Stella will usually show a max @ 295F-310F at extended wide open throttle. My CHT saved me when my scoot developed an air leak between the exhaust and the cylinder stub, max temps had shot up 40 degrees. I tightened the exhaust clamp before it got worse, and temps restored back to normal next time out.
This has it's own battery that lasts a long time, I've never replaced mine. I did use a dremel to slightly increase the 14mm hole size to make it easier to put on the plug. Also cut a "notch" in the plastic heat shoud's plug hole to allow the wire to follow out next to the plug.

I agree with other posters that 1) first install a CHT, 2) if you change an exhaust and filter - do it with a goal in mind (serious performance, or simply to remove the Stella restrictions and replicate the PX150, or whatever) and 3) if you do anything other than going with the PX150 exhaust/filter for reasonable improvement, then an EGT is beneficial - and can't hurt in any case. 4) Rely on your own plug & temp checks, not on simply what people advise because each scoot/exhaust/filter my have different needs.

If you only want moderate performance improvement by removing the Stella restrictive exhaust and filter, then a replacement PX150 exhaust and filter will do that. But you will still need to fatten your SI pilot and Main jets as a result.

Also note that the increased ethanol in gas has perhaps made some of the older recommendations a bit lean anyways. Your plug checks and CHT or EGT will show you that. I'm no expert, listen to the others who post who have a lot more experience than me.
fisher1..
thanks.. your first link was a no-go....
i found the 14mm sensor wire, but no display unit.
can you link us to the display as well as the sensor ring/lead?
thanks
J H
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fisher1
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Post by fisher1 »

Oops - sorry - looks like they remapped their site, try this link...

http://www.trailtech.net/digital-gauges ... temp-meter

Chose the 14mm spark plug sensor option and whatever color you like.

The 24" extension is log enough (with the wire that comes with it) to mount the display on top of the glove-box - unless they changes that too.
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Mike Zero
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Post by Mike Zero »

As I am a total noob at all this I would say that I am looking for faster acceleration. I have the CHT gauge but I still need to install it and record my readings. Could you explain how the temp readings relate to the jetting sizes? Are there any links you could share to a step by step exhaust install/jetting procedure?

I really appreciate all the advice. Thanks!
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BuddyRaton
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Post by BuddyRaton »

Running lean (less fuel in the air fuel mix) will make the motor run hotter. There are many things that can cause this... carb not jetted correctly, air leak at the head, at the carb, at the fly side seal et.

What happens is that as the heat increases metal expands until the piston is too big to slide through the cylinder. This can result in the motor...and rear wheel..locking up requiring top end work...after a change of pants.

While technically the fuel does not "cool" the top end in practice the higher the amount of fuel the cooler the motor will run.

The great dilemma is that a motor will be running the best it ever has right before it locks up. If you can see you are running hot you can pull the clutch...blip the throttle and cool it down.

There are tons of threads and posts about carb set up on our sister site MV in the NSM section.
"Things fall apart - it's scientific" - David Byrne
www.teamscootertrash.com

'06 Cream Buddy 125, 11 Blur 220, 13 BMW C 650 GT, 68 Vespa SS180, 64 Vespa GS MK II, 65 Lambretta TV 175, 67 Vespa GT, 64 Vespa 150 VBB 64 Vespa GL
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