Has anyone replaced the lower conrod bearing on the evolution 26 gt2, i have had 2 failures of the bearing in the past and i would like to just press a new bearing into the rod, anybody know the bearing number? I want to replace the bearing now it seems to have a little bit of slop and is ticking a bit more than normal by moving the prop hub back and fourth by hand.

The bearing number for most needle roller bearing are the size of the bearing, Measure the crank pin size and the inside of the rod, Most are in mm, Just make sure you buy a needle bearing that is made for two stroke gas engines.

The bearing is a standard INA size.
However, If the bearing has been allowed to deteriorate to failure, the crankpin also is damaged. A new bearing will not last long on a damaged crankpin.
Reasons for damage:
Failure to check increased play.
low quality fuel (<91 octane PON)
low quality oil (< sae30 weight 0r <10cSt@100°)
Too high compression ratio (head needs at least two shims)
Too large props on high compression ratio. Props should run over 8000 rpm.

My head has only one shim, but i run 96 octane fuel. 100 octane and 91 1/2 and 1/2, I run klotz R50 oil. and a 18X6 at just over 8000, i pulled the engine last night, the bearing is a HK0808 8X12X8 mm. PE do you know the exact nominal size of the crankpin? I used to work in small engines, snowmobiles and ect, we rebuilt cranks at our shop and most of the time the crankpins were ok with a slightly bad lower rod. so hopefully mine is within tolerance. It seems like the rod is rubbing on he backplate more than it should. It has worn a probably .010" grove into the back of it. when i pulled the backplate i noticed some small metal shavings on the end of the crankpin, i am wondering if these are entering the bearing and causing it to prematurely fail. The other times the engine has failed it has been under warranty, now that it is not underwarranty i want to catch this thing before so i dont have to do a complete rebuild after the bearing particles ruin the piston and sleeve and take out the crank.

Ok so I was curious so i pulled apart my engine to get a good look, i measured the crank pin and it is exactly at .3147" which is equal to 7.993 mm. and a 8mm bearing is .3149" so my crankpin seems to be good. once the engine is apart any slop in the bearing is not noticeable by look and feel.
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check the surface of the crankpin. It should be very smooth. Any pitting, and it is a discard item.
Smooth the back cover.
Dunk the Klotz oil. It has inferior high temp viscosity of about 6 cSt@100&deg;C you need to use 10cSt or better (SAE 30 grade or better). Be sure to use a fully synthetic oil.
Nominal pin size is 8 mm, so yours seems OK

Ok thanks for the input, the crank is good, i am going to pick up the new bearings this morning, they had them in stock in the local bearing supplier (INA HK0808).  $4.50 a piece not to bad compared to $40 for a rod from horizon.  It is also possible to get one with a oil hole, if i have another one go bad i may try that, most all larger 2 cycle engines i have worked on have them.  I would just need to drill the conrod to match.  Also hear are the specs of the type of klotz oil i am using.   It is rated at 18.2 CST @ 100C.  
<table border="0" cellpadding="3" cellspacing="0" width="311" height="516"><tr><td valign="top" width="800"><h2>Applications:</h2> Motorcycle/ATV: Hi-performance Racing 10K RPM+
Snowmobile: Drag Racing, Snow Cross 9500 RPM+
PWC: Racing 10K RPM+
Kart/Micro Sprint: Hi-performance Racing 10K RPM+
R/C Modeling: Gasoline 30-45K RPM <h2>Characteristics:</h2> </td> <td valign="top" width="191"></td> </tr> <tr><td colspan="2" width="100%"><table border="1" cellpadding="3" cellspacing="0" width="405" height="87"> <tr> <td width="140">Smoke Rating:</td> <td width="98">9</td> <td width="236">1 = fog - 10 = no smoke</td> </tr> <tr> <td>Clean Burn™:</td> <td>9</td> <td>1 = heavy deposits - 10 = no carbon</td> </tr> <tr> <td>Film Strength:</td> <td>10</td> <td>1 = failure - 10 = no wear</td> </tr> <tr> <td>Pour Point:</td> <td>-9°F</td> <td> </td> </tr> <tr> <td>Flash Point:</td> <td>550°F</td> <td> </td> </tr> <tr> <td>Maximum RPM:</td> <td>Unlimited</td> <td> </td> </tr> <tr> <td>Viscosity @ 100°c:</td> <td>18.20 cSt Typical</td> <td>16.30 cSt Min - 21.90 cSt Max</td> </tr> </table> <h2>Instructions:</h2>

Compatibility: Blends with gasoline and stays in suspension.
Fuel Stability: Will dissolve in gasoline at ratios of 15:1 or greater.
2-Stroke pre-mix DO NOT use in oil injection systems.
MX and Dirt Track: Water-cooled engines 60-125cc mix at 32:1, 250+cc mix at 40:1 to 50:1
ATV: Water-cooled mix at 40:1, Air-cooled engines mix at 32:1
Kart: Air-cooled mix at 20:1 to 25:1
Shifter Kart: Liquid-cooled mix at 32:1
PWC: Full mod mix at 40:1 to 50:1
Snowmobile: Full mod mix at 40:1 to 50:1
R/C Model: 2-Stroke gas mix at 20:1 to 32:1 </p></td></tr></table>

My mistake on the Klotz R50, I had the ModeLUBE TechniPlate® Synthetic  on my mind.
Please heat the rod when pushing out the bearing, and also heat it when you press in the new bearing, using a proper tool..
If I recall well, INA has the tool drawing on their web pages.