Bore Uma 57mm Piston

[sixty-thirty]

Has any buddy tested this product ?

im currently using mxking bore i think which is very like the vixion bore and pistion and i notice the comp is bit low ... so will adding a uma 57 machined pistion fix this issue ? i have seen most of you here do the squash .8 or 1 mm to improve comp but in my case i do not trust the machine shop . so i think the only way to improve comp is to change pistion

all responses are welcome

 

[RockRobin]

Has any buddy tested this product ?

im currently using mxking bore i think which is very like the vixion bore and pistion and i notice the comp is bit low ... so will adding a uma 57 machined pistion fix this issue ? i have seen most of you here do the squash .8 or 1 mm to improve comp but in my case i do not trust the machine shop . so i think the only way to improve comp is to change pistion

all responses are welcome

i have read someone else review on this modification from Malaysia Tuneboss group in facebook. looks like the throttle response is slightly better. the CR is uncertain from 11.3-11.5. some claimed it is way higher which is 13 or 14 CR.

please be assured you do the proper CR measurement testing before installing as if the CR is too high it will cost your engine to be less durable.

i am also waiting for peoples review on this new piston uma 57mm just because i wanted to cure my "disappearing engine oil" problem

 

[sixty-thirty]

Wanted to reply to this for like 3 weeks now .. for some reason i could not sign into the page.

Is 14-13 on stock head ? Im also aiming for 11's ... and are we suppose to use 2 piston ring or 3 ? Stock one uses 3 right ?

 

[❤️Rap❤️BR]

hello guys i want to have more power on my smx 135, and im planning to buy uma 65mm block, sport super head and quick mission geart setand hyperclutch. is it ok for touring? atm im in stock bore&strokc, brt cdi, sun valve spring, faito ignition coil, oko 28mm. i want some beast on touring . hehe. i hope you can suggest guys what is best and where can i buy those uma products. thank you. more power pipz

 

[sixty-thirty]

I think with uma 65 you will need to change the crankshaft too, there are lot of factors you have to looking to when building a good engine ... do resecrh on this form and internet about how you want your bike and ask the mastershere too ..

 

[❤️Rap❤️BR]

I think with uma 65 you will need to change the crankshaft too, there are lot of factors you have to looking to when building a good engine ... do resecrh on this form and internet about how you want your bike and ask the mastershere too ..

Ok bro. Thank you. I found some mechanic that is tested and proven on 65mm touring set. Btw, thanks. Ridesafe

 

[sixty-thirty]

So after installing a mxking bore+pistion on a classic engine .. the compression pressure is 450kpa... on service manual it says 560kps ..from the yamaha serive center here they said it need 600kpa ... so im guessing it need some where in between 560 and 600kpa

 

[sixty-thirty]

"what we can say is the compression ratio is 12:1 for our piston." - uma racing