Why do I see soo many dropped valves?

[1579]

Just curious, seems like quite the trend with the YFM350. I was wondering if there was a concensus on WHY and how we can avoid dropping valves.

I have personally never dropped one myself but I have bought a few dead four stroke yamahas (warrior x2 and xt250x1) with dropped valves and major carnage.

Opinions? Damaged hot cam NO!!

Thanks
Brandon

 

[beastlywarrior228]

Dont over rev it

 

[E36graduate]

I have a 2001 WR426 and a recent 2003 YFM350. My opinion, seeing I bought a YZ426 bottom end and found a piece of a valve in it, LOL.....is basically that a lot of owners (no offense) probably never have checked and adjusted the valves on their aging quads/dirt bikes....basically just change oil now and then the engine eventually goes kapoot.

If you are taching the piss out of the motor, maintenance is needed more. Maintenance (if you are beating the crap out of the engine) is not just checking valve clearance...but also ripping apart the motor, checking ring gap and other wear items.

I have seen many engines with proper maintenance go for a long time.

 

[Gen1Pat]

Worn timing chains, and continuing to run it.

 

[warriorgirl09]

just face it... People DO NOT take care of a quad or bike the same way they'd take care of a car. and no offense but alot of kids have these things and they just flat out dont care because mommy and daddy will fix it when it breaks

 

[Gen1Pat]

Very true. But, most people don't take care of their cars either. I work on that crap all day. Lol.

 

[warriorgirl09]

Very true. But, most people don't take care of their cars either. I work on that crap all day. Lol.

take better car of them than they do they're quads lol

 

[E36graduate]

GREAT.....i just get a new-to-me warrior and in the same day my electric water pump on my twin turbo bmw is toast.....$600 part....guess I'm getting under the car today instead of riding the warrior....

 

[Gen1Pat]

Replaced a few of them on older beemers. Ya know what BMW means right? Bring Money With! I' never own a european car...

 

[E36graduate]

This is my 4th BMW (bring me woman....not break my wallet...lol)....this was the first bmw with electric water pump. That thing was burried under the engine....got it all set up and back to the warrior.

Got the valves all dialed in. Having a intermittent misfire/backfire/pop...hard to explain but usually at very low throttle. Recleaned the carb and air filter....still have this odd problem. Thinking its the throttle saftely switch...will take a look tomorrow.