bottom end condition?

[knobbyboy]

Bike was still running strong so I had not checked it. I could not get much if any up and down on the lower rod bearing, of course it has some side to side movement. I can get some movement on the main bearings by grabbing the stator. Should i be very concerned about the lower end?

[twowheels]

Originally Posted by knobbyboy

Check out the vid- wrist pin is in bad shape. Has a notch cut down into it. Question is the bottom end. All that metal went someplace before it left the exhaust. Bike was still running strong so I had not checked it. I could not get much if any up and down on the lower rod bearing, of course it has plenty of side to side movement but i think that is normal. I can get some movement on the main bearings by grabbing the stator. You'll see. So what y'all think? New top end and ride? Should i be very concerned about the lower end?

http://youtu.be/FMpr4JxfbuQ

What you guys think? (Bike is an 06 but was brand new 27 months ago.)

27 months - almost 2 and a half years. How much did it get ridden in that time period?

And where did that part of the wrist pin go (and likely parts of the the needle bearing too)? I'd be a little curious and use the time of heavy snow to split the cases.

You can satisfy your curiosity for the cost of a couple gaskets and potentially save a really big bang from happening at some inopportune moment in the near future.

[knobbyboy]

I have rode it a good bit. The needle bearing was intact, looks like the metal went away on the wrist pin. The bore and the piston look good. There is no snow here in NC/SC, next enduro race is in 4 weeks! thanks

[twowheels]

Originally Posted by knobbyboy

I have rode it a good bit. The needle bearing was intact, looks like the metal went away on the wrist pin. The bore and the piston look good. There is no snow here in NC/SC, next enduro race is in 4 weeks! thanks

Better get busy then A couple hours for the supercross Saturday and then back to the garage for you!

[robicon]

If that was mine I would want a new bottom, but it would really depend how far away the parts were. If I had a race coming and no parts I would ride it and hope for the best!

[desertgasser300]

With 4 weeks to go, if you can get the parts rebuild that bottom end and the top for piece of mind. Splitting the cases is easy and a complete rebuild can be done in no time at all. Then you can hit that enduro without the worry of, "my bike may blow up any minute!"

[knobbyboy]

main bearings i could do. rod and lower rod bearing- not sure about that, doesn't the crank have to be split somehow? i have no experience with that...

[HenrikSchmidt]

You can do it yourself, but you'll need acces to a hydralic press, and alot of other special tools, like a lathe or something to true it, to run within 2/1000mm.
But it's fairly cheap to get it fixed at any near by "motor machine shop"(or what it's called)..

[pscook]

Where are you located? RB Designs rebuilt my crank in less than two days turnaround, I was without my crank for less than seven days total including shipping. Cost was ~$70 (including return shipping) not including rod, I believe that Ron might have those in stock. If not, it's a CR250 rod and those are easily sourced.

Drop Ron a note and see what his schedule is like. I see that he will be closed at the end of January, but you should contact him for best results. Ron is located in Portland, Oregon.

http://www.rb-designs.com/

If that doesn't work for you, another option is Mr Crankshaft
http://www.mrcrankshaft.com/
I had him rebuild my YZ426 crank, again with quick turnaround and great service and communication. He is located in Benton, Kentucky.

Good luck, and don't forget that this forum has TONS of info and helpful members to get you sorted out and back running again.

[knobbyboy]

Have taken in lots of advice on this lower end condition. It has a very slight up and down movement but no fore aft movement and no in out movement. Just gonna do the top end this time. My neighbor works at an aviation engine shop and we measured the bore yesterday, it has very little wear from original. He thinks the wrist pin had a flaw in it that caused it to fail. I got my forks back from the suspension shop and they're back on the bike. Shock should be back later this week. Hope to be riding it by this time next Sunday.