New 175 making weird rattle after it's warm

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no_crf50_here

no_crf50_here

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Anyone had this issue? My new 175 making weird rattle (topend) after it's warm
Seems strange - just been on the fone to they boys at DHZ they were great, but just chasing to see if anyone else has had this issue.

Valves done nothing wrong there.
Taken cam cover off and all looks normal under there
About to pop the clutch out to see if the nut has come loose & remove the head just to be sure every thing is ok.

Any ideas?
 
well if it runs a short skirt piston then the rattle could be piston/bore noise, the short piston tb kits do the same thing.. you swear there going to detonate just by the noise..

hard to tell what the chinese are using in there 63mm bore kits, no one has been game enough to pull one down and do a review..

could also be rocker slap noise(floating side to side) early and some present klx style heads are known for this...

thats about all i can think of at present, all other items should be noisy straight away..

oh by the way is this a standard 175 or does it have a V2 head on it?
 
some of them are just noisey mate

the have a short skirt piston i'll get a photo of my old one

they are just noisy it sounds like a timimg chain noise but it's just a valve running noise and cumbustion run it chuck a screw driver to the ear and have a listen man

they make ya wonder
 
check the other thread going about the z175 engine... i could almost bet my lefty on it being piston noise due to short skirt piston
actually check this out, not sure what brand 175 you got there but..
CHP 175CC Powerful Engine - CHP

also check the thread out that rach made not so long ago regarding big bore kits.
 
yeah my chp makes a bit of noise most of my noise is in the air velocity thru the carby, its not that by any chance?
 
yep the TB 64mm kit sounds the same after its warmed up..

when i first heard it i thought it was the barrel fins pinging but we installed rubbers between the fins like the z155's have but the noise was still there..

its either piston slap or backlash on the crack and clutch gears.. but like i said id almost bet my lefty its piston slap..

could try thicker oil but then you run into clutch slip problems..
 
The short-skirt pistons TB was selling (since mid-summer, long-skirt and quiet), other have started to sell, besides Tak, are just shortened versions of the regular slug. NOT designed to run skirtless, and have too much clearance. A new Tak barely pushes through the bore, while the cheaper versions fall in with nearly .002" clearance. They'll slap some. Worse, once any additional wear happens, they rock in the bore and start tapping the head. Lightly. At first... You can crutch them by setting squish at a MM or so, and they won't tap for a while. Down side is they may go sideways in the bore before warning you with the head-tap.


Just my opinion, based on a bit of experience, with no offense intended to any builder, manufacturer, owner, etc.
Crap. I need to make that line my signature...
 
so he did

but like i say i've had 12 months out of mine and a set of oil rings and piston just because and it hasn't missed a beat so i wouldn't be to worried

not bad for the dreaded ceramic barrel
 
i say ride it like you stole it and fix it when its broke..

there plenty of these engines out there now and no sign of serious failures..
 
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