[Aprilia RS - Rotax 122] Measuring the squish

Standard squish : 1.5mm

[@wicyn9212]

Hi. What is the minimum and maximum size between the piston and the head should be?

[@miguelangelribes6213]

i like how the guy works..

[@laworders7307]

Hi Romain, tanks for nice videos, I wonder if you know if you can put Rotax kart engine parts like cylinder, head, and other parts on this Rotax 122?

[@romainquiban5469]

+Fixa Deal Hey, apparently Cylinder and Con rod are different between Rotax Max and Rotax 122. Source FR : forum.2temps.fr/viewtopic.php?t=8131

[@laworders7307]

+Romain Quiban Ok tank you, I not understand France, so total max cylinder can not fit on 122 crankcase? do you know g how to get max power out from 122 engine? I was plan to test it in motocross frame and delete balance axle and oil pump. what you think?

[@romainquiban5469]

+Fixa Deal They can not fit, source EN : www.apriliaforum.com/forums/archive/index.php/t-130897.html There is a lot of way to increase the power of your engine. The first main part to change are the carburator, the exghaust, and I don't know if your bike is restricted (air intake, ignition). When you already have that and you want more you can work on your cylinder or directly put a biggest cylinder (154cc for example). You can find that easily on internet

[@laworders7307]

+Romain Quiban Thank you, my idea was to see if I could build a Rotax motocross engine from it, with bigger carb, exhaust chamber like motocross bikes, lighter flywheel or ignition from motocross engines. I not need oil pump and balance shaft probably not need. Tank you for help.

[@romainquiban5469]

+Fixa Deal Good luck with that, seems to be a big project :)

[@alexsheriff3234]

Hi, I have a choice of 3 thicknesses of gaskets...used the thickest one and my compression is to low, should I try the thinner one I’m scared of the piston hitting!

[@romainquiban5469]

Well you should measure your squish to know that ;) If you still have the original con rod there is no problem to put the thinner gasket.

[@Tiwey]

its quite late to say it now. but litering out your engine removes the need to check the squish. and its more precise. all you gotta do is calculate the "geometric compression"

[@_roope_5082]

can this be used with other bikes too

[@turbinebass]

Hi romain, i change my engine piston and squisch is 1.86mm.Interesting why manual say 1.5, i think like you impossible and i used like you 0.3mm gasket.i tested with 0.5mm gasket squisch is approx 2.00 mm.

[@romainquiban5469]

turbinebass yeah I think it was possible with the Rotax 123, which had a different cylinder head

[@turbinebass]

Hi mate, How should the standard be?

[@romainquiban5469]

Hi, the standard is 1.5 but it's impossible to reach unless you replace the cylinder head or machine it

[@vilocvo5741]

Thank you

[@lilianemoro6524]

I'd put the stick in "S" to prevent scratch in the barrel due to the cut !

[@lilianemoro6524]

1:50 Serrage au couple et en escargot !!!!

[@mariomarjanov91]

I had 0.3 gasket on i my power band was strongest on 11500 rpm to 12500 then stops. Won't go over . Now i put back 0.8 gasket and lowered cylinder head. to put that power belov 11500 rpm.

[@l0ckd0wn360]

using the tape makes the entire point of checking pointless as the tape adds thickness and prevents a equal squash.

[@romainquiban5469]

Kyle Taylor Hi, the tape is situated in the middle part of the piston so it doesn't touch the cylinder head. The tin stick reach extremities of the piston so it will be crush by the cylinder head. The tape is just here to maintain in position the tin, but it does not influence on the squish measure

[@l0ckd0wn360]

good to know thanks.

[@lilianemoro6524]

Talking but dont know ...