KX Riders

Maintenance & Technical => KX450F / KX250F => Topic started by: ToomanyKaws on April 21, 2009, 06:02:21 PM

Title: Stock piston and wrist pin in 06 450f
Post by: ToomanyKaws on April 21, 2009, 06:02:21 PM

Engine was a making some noise at 9 hours.  Had changed the oil twice already.   Tore it down.  Wristpin was a little scored.   Typical of the 06 as reported.  Put in a new Wiseco kit.   Bike feels a little more responsive.   Don't really like 4 strokes much, but like the bikes handling and chasis.    Even went back to stock gearing.   Its down for top speed compared to other 450's but works better for me with the 50 tooth rather than the 48.    When this bikes engine really lets go it will get a 500 motor to put in.

Title: Re: Stock piston and wrist pin in 06 450f
Post by: hughes on April 21, 2009, 11:52:42 PM

I'm no expert on four stroke engines but a scored wrist pin doesn't seem typical for any manufacture in 9hrs of use. You got an hr meter on the bike right?? Hope the new parts serve you well.

Title: Re: Stock piston and wrist pin in 06 450f
Post by: jfabmotorsports.com on April 22, 2009, 01:47:13 AM

Don't wait for it to let go. It is worth more running than it is broke. Sell it and buy a 500 engine.

Title: Re: Stock piston and wrist pin in 06 450f
Post by: ToomanyKaws on April 22, 2009, 03:24:50 AM

I tried to sell the engine brand new, when the bike was new in the crate.  Had it on ebay for $2400 or offer.  Most anyone offered was $800.    Had it sold for anything close to $2000 could have found a decent KX500 and been building the AF.
If you search the 450F forum on thumpertalk.  Pretty common for the 06's to have wristpin problems.   Dealer fix at first was to use an updated part number, then an 07 part number.   Most guys who do their own work, like me.  Just put in an aftermarket.

Yes the bike has an hour meter.