Alrighty then.

I've got this GY6 motor in a scooter ( i know this is an ATV forum but please; bear with me )

Now before having this engine model in a scooter, i've worked on it on gokarts and both problems with those were remedied by a carb rebuild.

For this one however, i rebuilt the carb, redid the oil (gear and engine). It starts and almost sounds like its knocking. It also has pretty low miles ( i believe 2000? )

Before i go and buy rebuild kit with new top end and piston, does anyone else have any other cheaper alternatives? Im not a SUPER engine genious but i've learned everything i've done from Google and commmon sense.


PS I also found a video of a guy having the same issue and his little rocker was SUPER loose; so i recently took the cover off the top and both things were tight. Reading the issues with compression as im seeing; i don't have a way to measure it (or maybe i do; if anyone could enlighten me )

Thx for all responses that follow

 

Welcome to the forum siriontc3!

Wow never heard of a knocking GY6 before...some smoke a little on start up... Im guessing youve checked the valve clearance? Probably more of a tick from a tight valve than a knock though..

 

Well, i took the valve cover off and looked at it. Looks like its got some plate inside of it. Can you show me what the inner side of the valve cover is supposed to look like?

*EDIT*

So apparently its supposed to be there. the "Valve Cover Plate for 150cc and 125cc GY6 4-stroke engines." is what it is. However this one has a rather large bend in a part of it and looks as though it was glued on and not "screwed in" as this one shows. Pictures anyone?

*EDIT2*
Heres a picture. Not only does the inside of this thing look sorta mangled but it also looks as though the plate that was ORIGINALLY in there was never removed, and a new one was put atop of it. THEN the original owner i guess decided to put some sort of expoxy or some sealant (idk TBH)
Check it out:





For those who cant see.
http://img121.imageshack.us/img121/4205/0104101242.jpg
http://img526.imageshack.us/img526/9692/0104101243.jpg

HALP before I have to pay someone to do this or scrap it!

 

Just popped the valve cover off one of my GY6 engines...wish i had my camera at my shop... Mine has a 2 layer metal plate...very similar if not exactly like yours, but with no abuse.. and no epoxy....Ill grab my camera later today and post a pic..

 

Thank you. I've since popped the thing off. IDK what it is. I want to take the thing out of the scooter but im just worried about it and no shops around here do work on them. For me while its starting the noise isn't there (very smooth and as its supposed to sound), and as soon as it comes up, it starts and makes this horrible knocking sound. Im thinking as though its a piston/crank issue at this point since i can't think of antyhing else. I also replaced the spark plugs (however it made the sound before i put the new plugs in as well)

 

I would try taking a short piece (3 feet) of 1/2 inch tubing (or garden hose) and use this as a stethoscope. Put one end of the hose in your ear and the other at various places on the engine. You should be able to localize the source of the noise.