Aprilia RS 125 How To Improve Performance - Piston Squish

Hi viewers. Welcome to Tom Did It.
In this video I show you how I improved the performance of my Aprilia RS 125 2 stroke. By skimming 0.5mm off the combustion chamber and reducing the squish gap reading, the compression and efficiency is increased, therefore improving the performance of the engine.
Enjoy and thanks for watching!
Tom Did It

[@nhskan]

Another great video Tom!!

[@tomdidit4216]

Cheers Nick.

[@trianedtog0417]

This channel going to be best on KZbin watch need a Instagram page

[@garysmith70]

Lovely bike Tom, but please get some gloves on and jacket..

[@astonrichardson4309]

You have a nice bike Tom 👍

[@tomdidit4216]

Thanks Aston.

[@Subliminal3117]

Please do more riding videos :D

[@tomdidit4216]

Will do Phillip👍 Thanks for your comment!

[@indonasty7229]

Hi tom i watch many time ur video , i used aprilia rs 125 2012 aswell but could u help where i can get spare part like u buying new one and plug and play thnks so much and good to hearing back from u , cherrs mate

[@tomdidit4216]

I usually use PJME. They are a UK based company with the good website. I have always found their pricing reasonable.

[@aloy101268]

hey tom, I'm riding a 2010 rs125 as well, try riding the bike above 5-6 k rpm. anything below will sound boggy and feels slow! esp when travelling low speeds, i keep myself within 3 gears. Happy new year!

[@tomdidit4216]

Hi Aloysius. Thank you for your comment. It seems we like to ride our bikes the same 😀👍. Happy new year to you to. And happy riding riding 2022.

[@dvandam9574]

These bike are made to rev … thats why they sound this bad on low revs… 1 solution… keep it over 6k 🏍

[@trianedtog0417]

Best channel on KZbin for the aprilia rs125 were did you buy your piston and head from have you got a link sir so what's next 34mm vhsb dellorto pjme got loads in store and you don't pay tax thanks Paul uk 🇬🇧

[@tomdidit4216]

Hello there TRAINED TO GO. As always, thank you for your support on the channel! It’s likely my next video will be on tuning the 28mm PHBH carb that’s currently on the bike. I’m considering the 34mm carb option with PJME, however delivery to Sydney Australia takes about 2-3months. I may have to try and source one locally in Sydney?? -Wossner piston was from F1 moto. They can be found here www.f1moto.com.au -My head work was done by Greg Ball Motorcycle Engineering, Kirrawee NSW 2232. Hope this helps mate👍.

[@trianedtog0417]

@@tomdidit4216 great reply if you want to really lower the squish use threebond gasket glue with no gasket 0.8 our race bikes are set up we use two spark plug orings with silicone so no water leaks

[@tomdidit4216]

Ok, I’ll keep this in mind. Thanks!

[@Endrjo]

Hi Tom. Like your videos a lot. Where do you live? Why did you chose a 125 2T rathert than bigger 4 stroke engine?

[@tomdidit4216]

Hi Adrian. I’m glad you like my videos. I’m based in Eastern suburbs of Sydney, Australia. Do you recognise the area? I grew up riding 2T and have a 2T background from my MX days. I like the 2T power delivery, the sound, the smell and easy maintenance. You could say I’m reliving my youth on this little machine 😀👍. What do you ride?

[@Endrjo]

@@tomdidit4216 That's what I thought, Australia, because it's too sunny and pretty to be England. I ride a 1975 Yamaha rd250 -alsi 2t. I have recently been thinking about an aprilia. I like it visually but i did not have a chance to ride it.

[@tomdidit4216]

@@Endrjo Glad you liked the scenery. The video was filmed around Bondi Beach. RD 250 is a great bike! I’m actually thinking of getting some sort of RD next😀👍. The Aprilia is fun. Built for going fast between corner to corner.

[@dvandam9574]

Hi Adrian , one advice get a Aprilia and drive the hell out off it 🤟

[@TheMOTP]

Hey Tom, great work. Sorry if I missied this part of the video, but what was your compression after the skimming? It increased from 100 psi to?

[@tomdidit4216]

Hello there AcTiVe TV. You didn’t miss it, I lost the footage!! My apologies for this. I now have 115-120 psi with new top end and 1.25mm squish. Not great I know, however it has made a real improvement to the engine overall. The compression may increase as the new components wear in? Let’s see. Thanks for watching. Cheers

[@TheMOTP]

@@tomdidit4216 Hey thanks for the answer. That is a great improvement. Quite a lot of compression gain from such simple "fix". Keep up the good work!

[@tomdidit4216]

Cheers pal.

[@trianedtog0417]

@@TheMOTP you got a aprilia rs125

[@TheMOTP]

@@trianedtog0417 No, I don't. But I have a similar machine, Honda NSR 125R, it's two-stroke as well and has similar power. Right now it's undergoing a full top rebuild. I had a hole in a piston, and the cylinder was totaled...nicasil on the surface of the cylinder was to be replated. I bought a new cylinder, a new piston (wossner) and all the parts. Right now I have to exchange the piston I bought because it's a little too big, it should have been 0,01mm smaller. I watch Toms videos because I like two-strokes and they are built quite similar ;)

[@davidbates247]

What size main jet are you running out of curiosity Looks like it goes well on the 28 mm carb

[@tomdidit4216]

Hi David. Firstly, thank you for your comment. You’re correct, I am using a 28mm carb - PHBH to be exact. The main jet is 120. Fyi - I’m in the process of making a video on carb settings and tuning (it may be of some interest to you). Thanks again.

[@JaapGrootveld]

Tanks for that last bit mate, It,s the krown on this video. I,m i richt to say its running a bit rich?

[@tomdidit4216]

Hello there Jaap. I agree, it is running a little rich👍. It could be the 2 stroke coating I have added to the new top end and cylinder components, or the jetting? It’s also not a bad idea to have it slightly rich as the new parts wear in. Fyi - it’s likely my next video will be on carburettor basics and tuning. I’ll hopefully address it in that video. Thanks for watching! Cheers.

[@jamesbrown2163]

@@tomdidit4216 I look forward to the video on carburettor tuning. My 28mm VHST has pollution gear on it and it's hard to get the correct specs for jets, needle etc. A new 34mm carby and manifold is coming soon.

[@tomdidit4216]

Hey James. I’m working on the carb video now :) I have heard bad reviews of the VHST and it’s tuning issues. I’m sure the 34mm setup will be a real improvement.

[@jamesbrown2163]

@@tomdidit4216 I look forward to it. Hard to ride much with all this rain.

[@michaelmarchei8539]

She goes a bit harder then my SR50 scooter LOL. miss that beast...

[@tomdidit4216]

SR50 is also a fun bike👍

[@jonahua5603]

Hi bro can you buy 180ish kit if so what would you recommend 👍🏻, I have a 4 stroke

[@tomdidit4216]

Hi Jonah. Thanks for your message. Do you me a 180cc kit? If so, I hear the 140cc kits are the most fun as they like to rev, but this is on the 2 stroke bike. Sorry I can’t be of more help.

[@testaccount4191]

You should go all out and run in on 120 octane leaded race fuel

[@tomdidit4216]

Tempting, LOL.

[@stallion63m35]

Did you do a compression test after the skimming ?

[@tomdidit4216]

Hi there. Thank you for the comment. Yes I did however I lost the footage! With new top end and 1.25mm squish it now creates around 115-120 psi (cold engine). Not amazing I know, but I can definitely feel the improvement. As the parts are really new, i think these results may improve as the piston and rings bed in etc etc? Cheers.

[@MatteoSione]

Hello Tom. I'd like to ask you some information about those fairings. Is there some social network where I can write you? Thanks!

[@tomdidit4216]

Hello Matteo. Yes I do. My Facebook page is Tom Did It. Please search for me on there👍 If you can’t find me, message back. Cheers

[@Subliminal3117]

What is your opinion on engine braking with a 2 stroke? Great video though! :D

[@tomdidit4216]

Phillip, hi I think it’s ok for a short time. I don’t rely on the engine brake when I travel down long hills. I clutch it and brake. Providing the bike is not running too lean, general riding should be ok. The worst thing I see is when people Dyno tune 2 stroke bikes and leave the back wheel spinning at full RPM. Hope this answers your question👍 Thanks for watching.

[@Subliminal3117]

@@tomdidit4216 It really helped thanks. Cheers

[@janeblogs324]

But is this bike premix or oil injected?

[@Subliminal3117]

@@janeblogs324 oil injected

[@dvandam9574]

Don’t do it unless u are racing it fullout, this means that u will go full power after a couple off seconds off enginebraking and only if u premix 2,5 % off the best oil U can find

[@danielmantio7905]

Had my italkit 140 single ring done 500 miles with full rebuild bike was a pain 145 psi it always wanted to open up early on the revs some people do 1000 or not even 100 miles and rag it I thought I done well 500 miles then ride it like normal and open up now and then

[@tomdidit4216]

Sounds good. I’m thinking of the 140 kit from PJME🤔

[@danielmantio7905]

@@tomdidit4216 140 kit single ring from pjme is best for these bikes believe me I used 154cc in Sicily bit more power but sluggish mid and low range . Warning!!! make sure you use PV spacers on the power valve I use the original one and spacer is 💯 need or blade will hit piston .

[@krolzizi1]

My bike do 170psi is that to much sir? What will happen if I have to much compression?

[@mozer30]

It depends on the octane rating of the fuel and jetting. If it’s low octane then you can have detonation problems, especially if the jetting is on the lean side. Some people compensate for detonation problems by richening the fuel mixture (larger main jet or needle type/clip position). A cheap way to reduce compression is to fit thicker base gaskets….or replace the parts that are causing the problem.

[@Subliminal3117]

How many psi/bar does the bike have now?

[@tomdidit4216]

Hi Phillip. Thanks for leaving a message. This is a good question. The wossner piston has done about 1500kms now, so it is well bedded in. I should check. FYI - it had about 135 when brand new. Cheers T

[@gtisid]

sounds like its bogging low down? pilot to big maybe?

[@tomdidit4216]

Hello Antony. Sure, it is a bit sluggish from idle to quarter throttle👍. Not sure if it’s the extra 2 stroke oil coating I’ve been adding to the top end during the rebuild etc etc, or pilot jet, or A/F mixture screw. From memory, i think my pilot is a 60? It’s likely my next video will be on carburettor basics and tuning. Let’s see if I can address this in that video. As always, thanks for the comment. Cheers.

[@copisetic1104]

Use a thicker o ring

[@sailormoon2548]

That's a trade secret your showing!

[@tomdidit4216]

Not sure which part, but hope you like it👍 Cheers

[@rider2two612]

nice bike :) i loved aprilia. i have 125 :) look me video

[@tomdidit4216]

Aprilia RS 125 black Bacardi Livani. A great video with soundtrack! Well done.

[@samuelford]

just put a 34mm carb and a 144 athena head on it.

[@samuelford]

and wear jacket and gloves!!!

[@tomdidit4216]

Hi Samuel. They are the great mods. I’m seriously thinking of doing it to my bike… Acknowledging your other message. I agree. No excuses. I should be wearing a jacket and gloves👍

[@dvandam9574]

Driving with no gear 👍🏻

[@tomdidit4216]

Hi D. Knew I’d get smashed on this one. Not doing it anymore…

[@dvandam9574]

@@tomdidit4216 just one question. If you do all this work ( U did this very good ) why not put a 140 on it? I setup mine with a 140 italkit 34 carb with 16/40 sprockets , full arrows exhaust , it goes 170 km/h and goes from 0 to 100 in 4 secs its a beast now, keep working on it and drive it bro. Guys always wear gear plz

[@tomdidit4216]

Thanks for your question. My bike is in good original condition with very low Kms on the clock. I bought the bike with 3000kms on it, now it’s done 5000kms. By keeping it original it might be more valuable one day? However the engine mods, sprocket change and performance gains are very very tempting... the RS responds very well to tuning!

[@dvandam9574]

You can always keep your original part and reinstall when u want to sell it, meanwhile you will have twice the fun 🤩 I see that you know what your doing so this will be no problem for U . Grtz from Belgium 🇧🇪 Ride it like U stole it

[@jamesbedford6642]

That don't sound to good bro n started slow u dun all that with 28 mil carb

[@tomdidit4216]

Hi James. I found the 28mm PHBH had to get right. The current 34mm VHSB is much easier👍 Thanks for your messages. Tom

[@jamesbedford6642]

All that bother thought it was a track bike lol Ur riding round bare arms no gloves ringing arse of it on new head n piston ffs get some leathers on n gloves go to a track n ul see how fast it ain't