Possible Crankcase Crack Issue Needing Advice

[DaveBrit]

I'm hoping someone can provide some advice on a possible crack in the crankcase, i.e. is it an issue I need to be really worried about?  I have highlighted the area of the crack in the picture and the crack goes about half way down the recess in the case that holds the oil pump.  I noticed it after assembling the two crankcase halves however it was there before (have disassembly photos to prove it, honest!).  The crankcase bolts are all torqued correctly according to Randy's advice.
Thanks - DaveBrit

[ribbert]

I'm hoping someone can provide some advice on a possible crack in the crankcase,

Is it definitely a crack or a surface casting flaw? They can look like a crack if you haven't seen one before.

Noel

[yamaha fj rider]

+1 Looks like a casting flaw to me but hard to tell from just a picture.

Kurt

[FJ_Hooligan]

Try gently running some fine sandpaper over a small section and see if it disappears.  If it does, then it's just a casting mark.  Could have been a stray strand of debris during the pour.

[DaveBrit]

Thanks for the suggestions.  I tried the sandpaper recommendation and it does really seem like a crack (see picture below). It's too fine to get anything in the crack such as the smallest feel gauge or a cigarette paper.  My question is can the bike be used and just live with this crack or is it more likely to cause something catastrophic?

[FJ_Hooligan]

I'm not sure of the location, but if it's not a stressed location and if it doesn't have pressurized oil behind it, slap some JB Weld on it and keep an eye peeled.

[DaveBrit]

Just to update this thread with where I landed on this.  Based on some offline advice by a seasoned FJ mechanical type person I just bolted the thing up and didn't worry about it based on the fact that both sides of the metal surface are internal and in oil and therefore not pressurized.  The bike seems fine for it at the moment but will report if it doesn't like it in the future.

Thought you might like to see the thing back together...

[ELIMINATOR]

 

[Joe Sull]

Quick, shut the door before the police drive by

I figured you just got back from a beat session