YX or Z155

[AntNZ]

doesn't matter what the bike weighs mate youll need a rimlock on the rear or youll be forever ripping valves off and 30psi is more than double what you should be running....,between 10-20psi max, I run 10-12psi on mine.
Dont run full synthetic oil ever in these engines, bad for wet clutches!
I've always used castrol power1 GPS 4T 10w-40 part synthetic based oil without any issues..
depends how hard you work the engine with regards to oil change, I do mine every 4-5hours, check valves bout the same
.003" inlet and .004" exhaust.

 

[Jope22]

Welp,i install it when i found some rimlocks in my shop! Should i punch little dent on it with center punch and drill hole there? and where just about? opposite to valve? I have heard that weights help rebalance the wheel and i could try to balance it close as possible just on the axle.If i break the chinese tube its no worry then and then i install the rim lock and michelin heavy duty tube.My riding style is pretty easy, i dont like to rev the piss out of these engines.Just casual riding and sometimes full thorttle and stuff,i dont burn rubber with these bikes just enduro and road so should be fine with the 4-5hour oil change.I ride long rides and i dont have van or pickup truck so the bike should be reliable!
my mind is just getting towards the Z155 because it looks way beefier than yx160 and my friend (nuubishaac) has lot of hours in his z155 and he does lot of burnouts and all sort of stuff and works fine.He tells me that he has 16/27 gearing on his Skyteam Z50 copy bike and pulls like truck and goes fast.Goin to order it from pitbikespares maybe and IF yx160 from parker racing.

 

[AntNZ]

yeah mate opposite the valve 180deg....better balanced wheel and easier to change tyres/tubes.

 

[XXX-747]

Good luck with it just be sure to break it in properly and get yourself an hour meter
And don’t forget to replace the oil straight away
And post some pics of your ride dude

 

[Jope22]

Yep,i will post them sometime.Does anyone have photo with Z155 on bike? not sure will it fit because the frame could get in way.The yx160 would be 10-20euros cheaper.and i just like the fact that it has longer stroke and oil window and oil window would be important to me because i check oil level before starting.I will post couple photos like tommorow of the frame not sure is it 110 style frame?? never seen frame like this what i have.

 

[Noongzy]

Yep,i will post them sometime.Does anyone have photo with Z155 on bike? not sure will it fit because the frame could get in way.The yx160 would be 10-20euros cheaper.and i just like the fact that it has longer stroke and oil window and oil window would be important to me because i check oil level before starting.I will post couple photos like tommorow of the frame not sure is it 110 style frame?? never seen frame like this what i have.

Go the z155. Mines been sweet and serviced after every ride. Goes really hard for a little motor

 

[XXX-747]

 

[Jope22]

Thanks for the photo,couldnt get good image today as it was very rainy.I hope that that z155 will fit.Does YX160 or Z155 have power differences?

 

[XXX-747]

All good bro I honestly don’t think there’s much difference the z maybe has a shorter fist gear that’s really it but who actually uses first gear lol
with standard sprockets the yx would have better top speed but would depend but power is about the same by memory the z has better power down low

 

[Jope22]

Ok,thanks for reply! I have heard that Z155 valve springs are monkey metal and it valve bounces alot? i also like engines which rev up fast so which one revs up faster? sorry for my stupid guestions but just want to know

 

[XXX-747]

Nah don’t be sorry bro that’s why there’s forums like this for questions

Good question I’d say by having a closer ratio transmition
The z would rev up quicker
And by memory the yx140 valve bounces really good lol can’remeber about the z155
And like anything you get good and bad ones specially if It was made in China

 

[Jope22]

Is the Z155 or yx160 much more powerful than YX140 with Z40.Today tested my friend Z50 copy monkeybike with that and it wheelied with blip of thorttle in every gear! Fun but scary to ride so i think the power of z155 or yx160 will be enough so i dont need any upgrades,and what i have chosen is that if the Z155 isnt in stock when im buying engine then i buy the YX160 because what i have understood is that theyre almost same engines so both good with proper maintance.

 

[XXX-747]

Yeah exactly the yx140 is a great engine
But it’s limited to future upgrades but you’d really only put a z40 cam in it and if there on a smaller bike they have plenty of power I’d say they would be about even until the z155 started working both the z and yx would pull away from a 140 on a straight road but around a small track it would depend on the rider but there a lot more than just the motor * tyres size carb sprocket

Every motor with proper maintance will do there job
And yeah in stock form either engine will give you plenty of power and enjoyment
And your moneys worth and in the future there are plenty of upgrades you can do with them to make your bike faster
When that time comes

 

[AntNZ]

stock z155 still has more power than a yx140 and z40cam, we race these 2 engines side by side every time we ride..

 

[XXX-747]

I love racing I remember with my old atomik 140 my cousin had the same and we’d always be side by side until I put the z155 on it hahahahha

 

[AntNZ]

they're good solid engines, mine have only ever been thrashed on the track, always getting their limits tested!!..., non-stop!! lol

 

[XXX-747]

Yeah bro I’ve punished all my engines hard riding Evertime lol
The best for that was my 140 valve bounced to the moon lol

 

[Jope22]

Got to measure the engine space for the Z155.If the manifold of Z155 comes in way then im out of ideas,if i dont have space for the manifold then i go for yx160 because almost same engines.Is it ok to run thicker oil in summer? In my 125 i had the valves adjusted little too far and with 10w40 it sounded very bad but with 20w50 no valve clicking noise at all.Not sure how to move photos from my Iphone 6S but ill try to find that out so i can send you some pictures of the frame.

 

[XXX-747]

You need to adjust the valve clearance correctly which a feeler gauge
The inlet valve should be set to 00.3 and exhaust valve 00.4
And you should use 10w 40 oil


Just click on the camera and then down the bottom where is says upload file so we can see how much room you have for the manifold you can always get a spacer and just angle it to the side a little bit

 

[Jope22]

seems like my seller of Z155 engines are gone so might need to think about the YX160.With yx160 should i be scared about the kickback? just wondering if i will crack the block.I have heard that you should modify the coil or the pickup sensor to make it spark later.Photos coming tommorow!