Crank Bearings

[Ponchojuan]

I'm rebuilding an 89 40HP VRO evinrude twin. After tear down the problem was a badly scored #2 cylinder. Likely culpret was the VRO unit. The mach-shop was able to bore to .020 and I ordered a rebuild kit from powerheadkit.com. Nice folks.<br /><br />They supply a new lower crank bearing, but do not include rollers or cages for the center and top bearings.<br /><br />Should these be replaced? All the crank bearings appeared to have little wear.<br /><br />Your help is appreciated. Poncho.

 

[rodbolt]

Re: Crank Bearings

if they are in good shape they can be reused. I always replace the lower ball bearing. usually if it was a lubrication failure the bearings get wasted. why do you think it was a VRO failure ?

 

[Ponchojuan]

Re: Crank Bearings

The internals were very dry when I disassembled the engine, although the bearing surfaces, were only slightly discolored are not blue or scored in any way. The oil consumption seems to be lower than normal for the number of hours I've run this summer. I have to tear down the vro unit still to check the diaphrams. I'm tempted to just can the VRO and run mixed fuel. I just could not find any diffinitive problem to cause the serious scoring in one cylinder. I suppose it could just be wear.<br /><br />Do I need to crocus cloth the crank surfaces or should I just leave them alone?<br /><br />poncho

 

[Silvertip]

Re: Crank Bearings

If only one cylinder developed a problem you can't blame the failure on the VRO. More than likely it was a lean mixture problem on the bad cylinder. When were the carbs rebuilt last? Be sure they are squeeky clean and install new kits, then do a link & sync before you put the engine back into service. Run a pre-mix as well as the VRO until you have determined the VRO is or is not working properly.

 

[Ponchojuan]

Re: Crank Bearings

thanks for the tip. The lean mix sounds likely. I did have a problem with the lower carb early in the season.<br />I did get carb kits and plan to rebuild them this week. I will be sure to take my time a do a good job on them.<br />I was planning on running pre-mix through the brkae in period. I will likely rebuild the VRO anyway since the kit is not that expensive.<br /><br />I will also make sre to check the oil tank for water.

 

[Solittle]

Re: Crank Bearings

When you get the carbs squeeky clean blow alll the tiny passages out with high pressure compressed air - no rattle cans.