BMS evo 150cc issues....HELP!!

[rockfish]

bought a evo 150 from an estate sale for CHEAP!! 150 BUCKS!!

having some issues though that I need some help with
got the scoot to actually run for about 5 minutes YAY for small victories......BUT.....there is a HORRIBLY LOUD tapping sound as the engine is running. TAPPING not knocking!! I know the difference in the two! Obnoxiously loud.....Could this be the valves are set too tight?? or too loose even?? also once it reaches operational temp it will choke and die

I wanted to post some video of the actual issue so you can hear for yourselves but due to the INSANE weather here in NY I haven't been able to get any video of the problem up BUT my engine sounds IDENTICAL to this one.....to the T!!

this guy states however that he had a broken inner valve spring

could this be a possibility as well??



thanks for all the input guys....you're all lifesavers

[Rebel]

Welcome to the forum.

The springs on these do break. I'd go ahead and just pull the valve cover off and have a look. WhenI frst started reading the post, I was thinking, adjust the valves.

Go here to download service and owners manuals for the scooter, similar scooter anyway.

scooterrebels.proboards.com/index.cgi?board=manualsreadonly&action=display&thread=1320

[rockfish]

thanks for the info......what should I be looking for when I pull the head cover??

is there anything obvious that will tell me the valve spring is broken??

[Rebel]

Usually it is the inner spring, from what I've seen posted. You may be able to look and see if it is broken. If you can not see I think I would adjust the valves and see if it runs better, they may just be out of adjustment.

[rockfish]

thanks for the info......two more questions

is it wise to just replace the spring or the entire head??

and also....what do you think about the scooter choking out and stalling at operational temp??

could it be related to the valves or is the stator bad as well??

thanks for the help.....I'm pumped to be on this forum!!

[Rebel]

well to change the spring, you have to pull the head off. These heads are not all that expensive, you might want to just replace it. If you pull it off, it might be the time to consider upgrading, porting and polishing the head, big bore kit. all kinds of fun stuff. You'll find all kinds of threads here about pumping these things up a bit in power.

You might have a bad choke causing it to not run well after it heats up.