How many of you have thrown a crank/rod/crank bearing

[fitethesystom]

Whos done any of the following, how, and what did it cost?

-Thrown rod
-Crank out of round (symptoms?)
-Crank/connecting rod loose/slop
-Crank bearings
-Bottom end trouble

[yamablaster24]

out of the 5 400ex's i have owned the only thing i have ever done to a motor was stretch the timing chain. If you keep the motor oil changed regularly these things will run forever. I MX'ed a 1999 fully uncorked and it never game me any problems. Now if we pull yamahas into the pictures, i have ruined about 4 blaster motors. :eek2:

[fitethesystom]

oh yeah those blaster's are not yamaha's best work that's forsure
however the warrior and yfz engine appears to be really durable much like the honda TRX400 engine.

[fitethesystom]

Also who has replaced their cam chain, and WHY?

[FoxRacing81]

My rod went bad in my bottom end. Whenever it has side to side slack, it is fine, but whenever the rod has up and down slack, that is not good. (Don't hold me to that, I know it's either that or the other way around.) Well, mine did, so I needed a whole new crank. I also had to replace my timing chain because it was stretched and would jump time.

-Justin

[fitethesystom]

That's bad, man. How much can I get a cam chain for? I have no idea what's involved in getting it off/on the lower sprocket...
Someone said you can use a 450 camchain for 30 bucks, anyone know?

Let m know.

[FoxRacing81]

The 400ex cam chain is around 90 bucks. The 03 CRF450 cam chain is the same as a Heavy Duty cam chain for a 400, and yes, it is only around 25 bucks or so. Might wanna double check that it is the 03 cam chain, but I am pretty sure it is. You can get this through servicehonda.com

As far as changing them...no clue man.:confused: My mechanic does the bottom end stuff for me. Someone on here will let you know. If you don't have one already, however, pick up a Clymer ATV manual. Soo helpful. It will explain it to you.


-Justin