150cc T-rex Daytona motor - photos

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thanks for joining just to add that mate...i knew it would only be time before someone over there did...

your missing my point..
why arnt we seeing all these problems. yeah sure there was a cracked case issue but thts now been fixed..

maybe you guys need to learn how to ride and not thrash, or maybe they got too much comp. well theres so many factors its not funny..
and strangely enough no pictures to go with the stories...

oh well have fun
 
lol not a clue. say what you want the guys breaking these engines are ama pros. ride your yx or z155 in the woods and it will last a summer, ride it hard on a real mx track and it might last a moto. thanks for stinking up a very informative thread.
 
i didnt mean to stir the pot...
i have seen more tranny isues than anything. im not saying that all of them will fail. they seem to work great for some people and not so great for others.
we stop using the yx and z motors october of last year... hack may have some pics but idk. we filled the back of terrys van (firepowerminis) with all of them. lol
 
lol not a clue. say what you want the guys breaking these engines are ama pros. ride your yx or z155 in the woods and it will last a summer, ride it hard on a real mx track and it might last a moto. thanks for stinking up a very informative thread.

i havent done such a thing mate..

you made the claims.. you need to put more information to them or it means absolutely nothing...
as i said a few times now, we havent experienced any of these problems.. on the track and off the track..
sure they do have issues with clutches and gears but that cant be blamed on the engine, more rider error than anything...

god even jap bikes sht gearboxs and valves and so on...

you see so many different claims of comp ratio and out of the box HP its ridiculous. lol 19hp at the wheel...if it were true every man and his dog would be running one..
16hp out of the box would be realistic, which on a dyno would be on par with the z155 or yx160... but the close ratio box would make them perform different.

but in my eyes there no better than all the other china engines, and definitely not worth the coin. and since they have the same quality control as the rest of the zonger engines it makes it hard to justify the price. sht from wat iv seen they even have the same chinese casting marks on majority of the internal parts.

but an engine is only as good as you make it, as i guess you missed the thread from "no_crf_here" busted 22hp on his z155 with v2 head http://www.miniriders.com.au/minimotards/27625-video-will-say-all.html

:)
 
The ignition timing and advance curve on no_crf_here's engine must be set pretty well near spot on ...

Ignition timing and advance curve rates play a major role in not only performance ... but reliability as well ... And you also have to take into account loads and temperatures an engine will reach during a race ... Dirt engines rev higher at lower speeds , so you'd run less timing advance to allow for the possiblity that the engine might reach destructive detonation zone temps during a torturous race ...

The bigger Jap MX bikes use knock sensors and constant computer controlled timing adjustments to keep them alive and well ...
 
who claimed 19hp, not i. if you believe your $265 z155 is the best then god bless ya lol.
 
didnt say you did.. but everywhere you look does..

lol i dont even own a 155z.
if fact i own a yx150 and its from the first batch tht arrived in oz...
guess what, never had a major issue with it at all...perfect gears and never shat a case. only problems have been the 2 piece oil slinger and the clutch..

and this engine doesnt get babied i can assure you tht..

also how about you reply to all of a post..not just pick little bits out of it..
 
what do you want to know? seems like you know everything lol.
 
what mods can be done to the daytona? and are these mods as bang for buck as mods for z such as v2 head etc
 
have your read through the thread man? there is alot of mods mentioned in here. you can do everything new cam, head, bore, stroke. what else is there.
 
what do you want to know? seems like you know everything lol.

man in all seriousness it would be nice to see this engine you been working on in action..
maybe before and after vids would be good...

i can t speak for everyone here, you got a good write up on the mods you v done and you say the power is unbelievable (which i dont doubt) but im sure a lot of us here would like to see..
 
grnman: im more after bang for buck... theres heaps of mods for anything if you want to spend the money on rnd and custom stuff but im talkin is is better getting a z motor 155 160 175 and then puttin on v2 n all of that or goin daytona n doin heads and cams....
power per dollar is what im after... a comparison
or even just a price list
 
well i believe the daytona would be a faster motor as a comparison. you can put a head on the 155 and you can put a head on a daytona, but if you are after bang for buck, i wouldnt suggest the daytona option. i have just got a stroker kit put in my daytona to make it 160cc and the extra fabrication of extra parts was extensive, so if you pay labour at a shop for the fabrication just to put the +r head on then the budget is way gone.
why i say this is because the +r head requires a different length cam chain, so did the stroker i found out (but longer not shorter), and also other parts associated with this, so its a more expensive option than just putting a head on a 155z.
 
thanks for that!
yea i mean... if u go 155 or 160 or 175 and v2 n all the bolt on stuff... n make power similar to daytona plus head n same stuff... but for less money with the z then in my opionion its worth goin that way instead of daytona... so thats all i wanted to find out!
thanks!
 
i have certainly seen some really fast 155z's and they were only made up with bolt-on parts. you can get some power, i just personally feel more confident with the daytona's reliability.
 
see im trying to choose a motor for my motovert rx... and if a standard daytona makes reliable power stock that seems to be the go...
BUT if a 175 makes roughly the same power and is cheaper... i am leaning towards the 175...
the only problem i see with 175 is that it is very new engine and hasnt had any problems so far...
another prob with 175 is that i will need to figure out the exhaust because the rx is crf style
decisions decisions!
 
well i believe the daytona would be a faster motor as a comparison. you can put a head on the 155 and you can put a head on a daytona, but if you are after bang for buck, i wouldnt suggest the daytona option. i have just got a stroker kit put in my daytona to make it 160cc and the extra fabrication of extra parts was extensive, so if you pay labour at a shop for the fabrication just to put the +r head on then the budget is way gone.
why i say this is because the +r head requires a different length cam chain, so did the stroker i found out (but longer not shorter), and also other parts associated with this, so its a more expensive option than just putting a head on a 155z.

so wat extra fab work had to be done? can ya outline everything you did and what had to be mod'ed?
im a little confused as to when you said you needed a different cam chain for the stroker pin...how is this so...you not changing the height of the head unless you opted out for putting the correct piston in and used the original one, thus having to use a base plate..

see im trying to choose a motor for my motovert rx... and if a standard daytona makes reliable power stock that seems to be the go...
BUT if a 175 makes roughly the same power and is cheaper... i am leaning towards the 175...
the only problem i see with 175 is that it is very new engine and hasnt had any problems so far...
another prob with 175 is that i will need to figure out the exhaust because the rx is crf style
decisions decisions!

i would imagine that the 175 would make more power than the daytona in standard form...
and exhausts can be easliy made fit. cut and weld..done
 
correct sean, a 3mm base plate was made to make the compression realistic and thus the cam chain, chain tensioner and idler arm had to be modded to fit and be the correct tension.
 
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