Pitster Pro 155Z Engine Review

Mini Dirt Bikes & Pit Bikes Forum

Help Support Mini Dirt Bikes & Pit Bikes Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
has anyone seen the hp rating that east coast 50's have on their add for the t rex 150... 22HP...lol no wonder there's so much negative talk about them....the manufacturer cant even give an honest rating or at least tell ppl if thats flywheel or rear wheel...and include the setup from the dyno run..

but i spose at the end of the day HP means absolute sht... its torque you want to compare..
torque turns the tires and HP is just a wank factor
 
from my limited knowledge of the jap crap

genuine daytona and takagawa stuff is just add on

so you use you crf50 centre cases and build the rest using daytona or takagawa trick bits

so the 125 and 150 complete daytona engines and china made things i think i remember hearing that lifan have there stamp on the centre cases (haven't seen it personally)

look the daychina is probably a good motor but you still gunna have g/box issues i know they have serious oil pump issue's and piston and rings dont last long being a "race spec" engine and well when you can go just as fast for just as long for a 3rd of the price the case is closed

hell i'll let ya know how the zonga hold up when we pump 175cc through it
 
yea I guess it's hard to find the facts about daytonas thanks to the pricetag, no-one wants to buy it so no one gets to test it, I know I sure as hell wouldn't buy one unless I won the lotto.
 
wooow...everybody back off a bit(specially Pitbikekid)...I am definitely not Hackmunchs opinion , but he knows usually, what he`s talking about and got a bit carried away with his passion about the chaytona!!He was building for years the race engines for Pitster!!
The engine is made in the Zongshen factory, thats a fact...everything else is bla bla....so at the end of the ,day its another chink engine with parts in from whoever you know...we had two failures here with it too, I wouldn`t recommend the engine(for this given price) to nobody, but fact is , when they run they freaking rip!!....unfortunately not for long in some cases:p....but as the former boss of ferrari always said: If a race engine hold longer up then two races, it wasn`t tuned enough!:D
 
listen guys, dont take my opinion so personal, here is the deal i have seen and had my hands on stuff before it gets released to the public. tested stuff for pitster for a few years and other companies. the yx150 had big crank problems and we called them out on it in 2007, hence the yx160,the yx160 had case and clutch problems and we called them out on it. if we didn't you guys would have the same crap from a few years ago. we did this to "make" these no good chinese guys fix there cap or quit making it, well the same thing is happening with the z155 engine, these trannys are garbage, you notice how hard it is to get it in neutral? thats just the beginning. the problem lie in the cogs between 2nd and 3rd gear, they rip right off and then you dont have a tranny. 1st off the tranny is not "close" ratio, that was a complete lie from Pitster, all they changed was the primary gear ratio (like changing your front sprocket size lol). the clutchs are coming from the factory loose lol and the cush drive is still a huge problem. so has Pitster solved the problem, hell no they created another 1 lol, oh and just to make you guys feel better, the z155 engine is $20 cheaper than the yx160 out of china. just so you know we met with daytona, they flew in from japan, there is not 1 part on the daytona 150 made by zonshen, they just assemble it for dayona. they assemble them in runs every 60days and daytona is at the zonger plant inspecting every engine that goes down the assembly line. i am not saying i agree with there $1500 price tag, that price will come way down hopefully soon, but the proof is in the pudding. i have been to vegas minimoto for the last 3 years under the pitster tent and have never seen a engine dominate minimoto like the daytona 150/4 valve did this year. 75% of the fastest riders in the pro classes had the daytona engine. believe the guys that race and build these bikes before you believe all this mfg BS. my 2 cents.
 
yeah good to get a better understanding at his meaning to rubbish engines..

1 thing i dont get tho...all these issues you outline, why is it we havent had half of them...
sure we've had cracked cases and smashed gears but i dont think i could report 1 broken crank or severe clutch problem.
theres talk of the tranny's shttin but i haven't seen one.

do you think that your conclusion has something to do with the fact your were always dealing with pre-release engines?
because all that you say is simply hard to believe.
specially since we have the proof with hundreds of perfect engines with nothing more than normal problems..
we(i) have built a 176cc engine and a 196cc engine both of which the base engines are launch date yx150's(first model)
only one problem we had with one of those engines...dropped a valve and that was before the build.
both these engines get raced and bush bashed and treated like a $2 hooker

and the fact that my friends shop has sold and installed sht loads of yx engines in all varieties and guess what...the lifan engines (140,150) have a bigger warranty return rate...
 
well, i use to minimotard here in the US and we had engines last awhile but these ama pro motocross guys put a beating on these engines. if you guys are dragging knee the engines might last longer but for mx they just dont last. trust me i am not trying to bash anyone to death but the truth needs to be told. as for the preproduction thing, no we broke engines before and after production runs. we broke 2 z155 engines in about 30min both were tranny issues. i have seen a total of 5 break in the last month. like i said i have nothing to do with pitster anymore but the yx and z155 engines have along way to go to compete with the daytona 150. daytona has confermed that they redesigned the crank and all the engines shipped in the last 90 days have the upgraded crank and new close ratio tranny(real close ratio). here is a video of one of our teammates test the new piranha bike with stock daytona 150 .<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/cy6Z5NzVW9I&color1=0xb1b1b1&color2=0xcfcfcf&feature=player_embedded&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowScriptAccess" value="always"></param><embed src="http://www.youtube.com/v/cy6Z5NzVW9I&color1=0xb1b1b1&color2=0xcfcfcf&feature=player_embedded&fs=1" type="application/x-shockwave-flash" allowfullscreen="true" allowScriptAccess="always" width="425" height="344"></embed></object>
 
the 2 155z's you speak off, did they break on a mx track or motard track...
reason i ask is i wondering if these tranny related issues are due to countershaft flex from the chain running too tight on big jumps.. its maybe even flexing the whole engine and causing the crankshaft to run out...

its no secret that these bikes have sht swing arm geometry. the more the swing arm goes up the tighter the chain gets....

iv seen alot of these engines on mx tracks and if there were issues then i guess people would be complaining but there isnt that iv heard of...

by the way im not doubting what your saying. its just hard to take in because we dont have the problems here..
 
these trannys are garbage, you notice how hard it is to get it in neutral? thats just the beginning. the problem lie in the cogs between 2nd and 3rd gear, they rip right off and then you dont have a tranny.

I went out and tried , and neutral is the easiest gear to get it into?

Thanks for finally telling us what you no.

So 5 engines in a month! that you have seen with your own eyes? that just seems like a extremely high number for 1 person to experience.

Out of how many engines? like how many DID last lol....

i have had mine over a month , and it runs strong as hell.. probably 15 hours on it?

only thing i have noticed so far is a couple false neutrals .. but ive experienced that on pretty much every china engine i have ridden.

so i still have faith ... i mean how hard was these test riders riding??? i dont treat my engine like i should , i try and get it as fast as it can go .. WOT shifts , lots of decompression locks , thats just how i have ridden all my engines and they have never failed.

and im quite surprised this z155 hasn't , after hearing that you have personally seen 5 grenade?..




And if my engine ever fails , it will be straight up in a new thread!
 
ahh me and wogtaz are in the same boat.
Despite hearing your stories. I have faith in these engines.
If pitster pro can back then up then im not worried.
I will look after it so i dont see it failing any time soon.

I just paid SAGAONE for it :D looking forward to it!

Will be racing it on the 31st at the dirtmax cup!
 
apparently they've addressed the issue now but who knows still overpriced
 
yer definitely puts the daytona out of the question , if your looking for a new Crate engine..
no matter what it does , just cant justify that price .. and its been a long time with no price drop , so.... dont think it is gonna.

Did i read in hackmunch post , they updated the cranks?
 
i'd run 1 for a decent price IF they're proven to hold up but after the early problems i think it scared alot people off from spending big $$$ on their engines.
i heard a few people hint there maybe a price drop around the corner but again who knows
 
Last edited:
well in our area, like i said 5 have broke and none are still running, everyone went a different engine route. all we mx, none were minimotarding. if you guys are having good luck with them then thats great but there is no way in hell i would sell a bike with them in it. just spreading my opinion and letting people understand what we came across while testing these engines. yes daytona upgraded crank and tranny in the last 90 days. my 02 cents.
 
On MX tracks lousy riders can allow the engine to rev in the air ... then when the wheel bites on landing it shocks the crap out of everything ... Long stroke motors are worse in that situation since the greater crank leverage strains things a lot more ...

You'll notice that professional riders hold a steady part throttle in a taller gear over whoops ...

I don't like the 155Z's because they're STILL using a ball bearing on the clutch side of the counter shaft ... that shaft cops the most load and ball bearings aren't designed to handle heavy loads ... ie conrods run needle rollers because they spread the roller contact area over a wider surface whereas balls tend to impact and indent when they cop a shock load ...

Has anyone ever thought of WHY Honda went with a 43.7 mm stroke on their CRF150R race bikes ... yet they've gone with a 57.8 mm stroke on their sedate lower revving trail plonker CRF150F's ? ...

And IF these Daytonas make 22 rear wheel HP then they should hang with a CRF150R in a drag ... IF not then the power rating is merely BSHP ...
 
Back
Top