rattling noise ?- new motor ?

[jloi]

GY6 150 cc - This new motor has rattled ever since I  first installed  it and drove it . could  use some input from experienced  people please .  is this a common occurrence with new motors ? This is definitely something I should take a look at  right ? and  inspect variator , rollers etc. ? right ? It is definitely a roller type rattle .   Could this be the cause  of carb/scooter running rich.  I have about 200-250 miles  on this motor . Have put in 3rd spark  plug  now, each one has been black.

 Everything  is stock on this scooter . Upgraded to Keihin carb . Just ordered today sliders  for this variator .  12g.  I called where I ordered /bought this motor from , he couldn't tell me what weight rollers it comes with .

 The  old motor never rattled before or  after I replaced the rollers/variator  when the belt  broke . 

   I've seen different vids  including Brents' and Ill be watching  more  to  make sure I get  all this  on right .          

                any input is greatly appreciated since I have  limited exp -         Thank you                       

[90GTVert]

I would guess it's separate from the rich issue. If plugs are black, it should be attended to with some carb tuning or finding out what else is up like a clogged air filter etc... Then see if anything changes. Rattles are not uncommon. I would think it was strange if most of my scooters didn't make some sort or rattle. Could be nothing. Could be a warning sign. Sometimes there's not much you can do other than listen the best you can to pinpoint it and pay attention to exactly what makes it rattle or when it happens and then to inspect areas of the most suspicion.

[jloi]

Dexameth/Tyler has helped guide me a lot on the phone at PFS . Per your vid on rollers/sliders I just installed 12g sliders and I think i'll soon change /upgrade both variator and clutch assembly and maybe belt. I was telling Tyler as far as speed goes I'm only interested in increasing off the line/ bottomend speed. It goes fast enuff for at 55 . Hardly ever do that even . Scary for me . Not a long time rider like you guys . Too old . Told him my whole goal is to convert to Naked so as to make it more attractive/ saleable. I'm a perfectionist to the nth degree so I know I can do a good job. I just don't have tech. knowledge. but I'm getting there nevertheless .
I also went from a 102 main jet yesterday to a 100 . Din't have the desired effect . Also went up and down with the needle sur clip. So still tuning . Do I need to worry about dumping too much fuel into engine from too rich and ruining engine over an extended period of time ?


Thanks soo much for your reply . I remember your a 2t and I guess not especially 150 . so thank you . it helps

I'm not really conversant with the differences between 2t ,4t etc. .

I'm really amazed at the encyclopedic knowledge I see here from the various guys , Especially - OLD GEEK . but many others too . and your vids with your attention to details thru the years

edit:  forgot to mention - adjusted  valves  yesterday too. set both at .004.  sliders reduced rattle/clatter and  also valve adjust helped.

 I asked  in a post , don't remember where  , if I got the timing chain 1 tooth off could that affect  AT ALL   the carb/ running rich?  or otherwise  not timed accurately , maybe  just off the  mark a  little .   an example  of I just don't know . I google things sometimes searching unsuccessfully .