When is it time to do the Bottom End?

3 replies to this topic
  • TIG88

Posted February 24, 2009 - 12:45 PM


Hey guys. Was wondering when its time for a new bottom end, and if anyone had done one. Im a trail rider and never at any sort of track, so most of my riding is low rpm (usually below half throttle), with the occasional WOT passes through a field. What gets replaced typically? Just the bearings or the whole crank assembly?

I ordered all my top end parts off of the TT store a few minutes ago, so while im in there this weekend (or next), what should I look for?

  • JSanfilippo

Posted February 24, 2009 - 01:36 PM


Slop in the crank/conrod assembly. Specified limits are in the manual.

Another thing you should look at is the gear on the crank that drives the cam chain (you did order a cam chain, right?) If the teeth are rounded off or show wear the whole crank needs to go. The gear and the crank are essentially the same piece (nice design huh? :lol: )

Failure to replace the crank in that kind of situation may result the timing chain to slip causing the cams to jump time and punch a hole in the piston with one of the valves causing $expensive$ damage.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • TIG88

Posted February 24, 2009 - 02:41 PM


Yeah man I ordered the chain and the tensioner assembly just incase.

What I didnt get was a flywheel puller :lol: I'll stop down to the dealer and see if they have one.

On a side note, can the service dept. at the dealer hone the cylinder?

  • JSanfilippo

Posted February 24, 2009 - 10:18 PM


On a side note, can the service dept. at the dealer hone the cylinder?

Yea but they'll likely charge you a full hours labor.

You can de-glaze it yourself and run a light hone through it for alot less than most shops charge for an hours worth of labor.

Related Content


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.