A9 camshaft problem 150 cc scooter

everything is stock except for the a9 cam. my valves are good, they are both set to .004 Please help thanks

[coreyraikes]

Don't know if you fixed it already but your chain tensioner bolt is out😭😭

[mrworldwide]

Everyone keeps talking about his valve clearance but isnt telling him what clearnace to set it to

[nicogarcia]

Check the valve lash before you bend a push rod, you always need to reset the valve lash when you put a cam

[abdiasdalmasi]

That’s chain tensioner mate, adjust it

[piperpilot]

Valves making contact with the piston. No doubt.

[MrJDM-pumh]

Could be valve contact with your piston or your valve screw could be loose bouncing around in the engine I've seen it before take the valve cover off and take the head off and check everything

[mrcleanisin]

Just take the valve cover off and look. Also, you will destroy your motor running it without the shrouding for cooling.

[matthewhumphrey]

the cam sprocket is off on the cam, you could change position on chain and see if can line up more but also can destroy the motor. you can take the stock cam and test link my link see if start sounding like that but also easy to destroy the motor

[christophearcher]

I live in SE Asia, I see this a lot! I respectfully suggest you tear it down and check all settings as many responders have already submitted, but in addition understand this: A9 cams need a much higher ( static ) compression ratio to work correctly; minimum 11:1. Also you must use stronger springs...suggest 2.8, 5 coil springs from Taiwan or Indonesia. ( Nothing made in China) . Finally you must have roller rockers ( known as" silent rockers" clue is in the name!!!. Sock rockers have slightly curved faces for the cam to follow and with the steep closing ramps of A series cams they tend to ' slap' the cam, as due to their shape they cannot follow the steep closing ramps on the cam easily. Best of luck but please, as someone has already asked, let us know how you get on!!!

[heffedirte]

Timing chain tensioner is missing something bud

[patrickfarrington]

But please respond if you fixed it or not, for the viewers and subscribers. Nothing worse then asking for help and not helping others here.

[DahlDefense]

did you put the larger bearing on? i bet your cam bearings one is too small

[rick]

Yeah sounds like valve contact with the piston, upgrade valves to the 69mm valves they have stiffer springs so they pop back faster and puts less stress on the cam and timing chain.

[bluecobalt]

bro...you're supposed to put the chain tensioner back on lol

[jamieleehartley-cs]

You do know you need to adjust your valves after a change of part like that. Did you just tighten the head bolts down and are starting it like that. Also the chain tensioner bolt is out.

[Peckadelic]

For those wondering what the noise is, but never saw the answer. I can say, definitively, this is piston slap or the piston pin slapping the sleeve. It's not valve-piston contact. It's not timing. It's not loose tappets. My Gy6 buggy started with a similar noise, that I ignored as I interpreted it as valve train noise due to the high lift cam and ignored it. Over time, and a high performance head later (it didn't break, I wanted to see if the performance head would improve the noise) the noise from the crank now outpaced the exhaust and piston slap heard here. It would make my ears ring. I figured due to the intensity, maybe an exhaust leak, or variator came lose. I took the cover off, front variator, removed the drive belt, and re attached the muffler. Cranked the engine, let it idle, and covered the exhaust with a rag at RPM. Obvious as day where the noise was coming from, directly on the crank shaft. The noise initially started as what is pictured in the video, but taking apart the top end later on revealed a completely destroyed sleeve which had wrecked the crank bearings. Surpringly it still runs and drives fine, power delivery is normal, but you would literally have to drive with ear plugs in. If you hear this- get ready to tear your engine down, or pay for a new one. I am doing the latter, because I do not care to take apart an engine that I can get brand new for $300..

Hope this helps!

[waynesteinmacher]

thats valve slapping man the piston is hitting the valves

[GermanEngine-Unity]

Chain tensioner bolt isn’t installed…. Can’t believe you didn’t grenade that thing Shit happens mate easy fix

[waynesteinmacher]

yo dude came across you vid and as a scootyer mech you can do qwhat ya did with that set up but judging from that noise you may want to get 64 mm big valve heads the lift on a a9 can cause the valves to slap the piston
and if your going that route set the lash to 0.004 intake 0.004 exhaust to give it a stress free valve lash to break her in then after 400 or so miles set it tio 3 intake 4 exhaust

[xristos_supermoto]

you need reinforced valves springs.use from honda astrea 100cc kitaco valves