is it normal for there to be Cracks or cracking on exterior of engine case? 1992 XR600L Motor

I am looking at an available XR600L motor from 1992. Both for spare parts and in case I ever want to do an e-start versions of one of these bikes. Also interested because the bikes I am working on are pretty thrashed and having spare motors never hurts.


this motor is from a parted out 1992 XL600R.  I have seen forum posts referencing cracks like this and the fact they are, or might be, mold marks.


but these seem pretty deep or heavy to be mold marks only.  I wonder if this bike got hit in or around the shifter and flexed the case here? 


Any reason to be concerned about this part of the motor? I am pushing him on price, he was not negotiable at all earlier so I left him alone. he called me back and asked if I was interested still and he's negotiable.  I posted about this motor earlier but I got to see it up close this time.


the starter looks pretty good but the brushes are just toast. 


I couldn't turn the motor over as it's out of the frame, so head/etc is suspect. he claims he saw it run and run well before it was pulled to make a cafe racer of some kind. The project died and he still has the motor.


I could get the crank turned with a socket and compression feels solid, but those cracks/checking on the side case worry me....



I'd be careful with that, some of those cracks are pretty deep looking

You referring to the first picture being the worst............normal,they all have that..not cracks..flow marks through the sand when casting..



Those are not cracks, but lines from the casting process that have been stained with dirt and oil. I can see where they are raised and not deep, but stained and protruding from the excess metal.  Run your hand over and feel the raised bumps.  Mine has them also.


Just curious about a 92 XR600l and XL600R terminology.  Just want to make sure you understand there was not an e-start made for the XR600.  I think we talked about this before, but it just isn't the case.  If it has a starter, its a 650L.  In fact, I am looking at one of the pics you sent and it is stamped with 644 cc on the side (look under the cylinder fins on the right side).  So, this is from a 93 or newer XR650L.  Let him think what he wants, but just want you to realize that.


How much is he asking?


You also noted you couldn't turn it over because it was out of the frame, but that you could with a socket.  Which one is it?


These can be risky or also a diamond in the rough.  I just wouldn't take too much in what the guy says as he is clearly clueless.  He can't get the model or year correct, so can you really trust someone about if it ran or not.  And if the bushing are toast on the starter, how did it get going in the first place?  Did he bump start it?


Worst case scenario, its a parts engine to make a little more money that what you bought it for.  Best case scenario, you scored an engine at a decent price that actually runs.  Fingers crossed its the last one because that would be a nice find.

ah,   you're totally right, It's actually a XR650L,  and that's what he's selling it as,  I have been doing so much research trying to get my new-to-me XR600R's running I just transposed the numbers and put them in wrong. 


He does say it's from a '92 though so he does at least have the year off.  


I am still worried about those "Cracks", as my other two bikes don't have them there. they appear to be either machined or polished off of the exterior of the case.  these are pretty bad ones, but of course,  as a total newb,  I trust you guys that have more experience. 




As far as turning it over,  we couldn't turn it over quickly with a kick start or e starter to hear how the machinery is moving against each other, but I did get a socket and slowly rotate the engine. Unfortunately all he had was an SAE socket that was slightly oversize so I was being very gentle with it.   it does appear to have decent compression, as good as my currently running 92 and feels like maybe a little better.  


he's asking 350 but would take 250 and a bike. Seriously. he wants a road bike of any kind to get around campus at college. for 250 I will take it no matter what condition, so I'm currently trying to find a cheap decent bike.  haha

I would just offer 300 with no bike and call it good.  In parts alone you could probably triple your money if the inside is decent.  And you never know, it could actually run for you.

As was stated, those are just casting marks, nothing to worry about.  And $350 is a good price even if it doesn't run.  Most good running singles fetch at least five or six hundred, guys on ebay are asking more than a grand for these in particular.  Hell, I once ebayed a Kawasaki Sherpa 250 single for $600 and it sold in a matter of weeks.  He must not have it advertised or is in a big hurry to sell if he called you back, but still, if you want it then don't mess around and get on that thing.  If I lived in Utah I'd would have already bought it for $350 without a blink.

Edited by Carter Pewterschmidt

This has been covered before just like the blue crankshafts and I'd be able to find those threads if the search engine on this forum was worth a damn. The old vBulletin one was.


Bottom line: it's not cracking. Cracks aren't raised above the surface. What those marks are from is surface cracking on the casting die. It is not at all uncommon for high production die-cast parts to have those marks. I'm also pretty sure that the only sand cores used anywhere were for parts of the cylinder head.

Yes, they are just casting marks.  A true test is to add oil to the case.  If those were cracks then they would flow oil.  The other thing is that if they were actually cracks then there would have already be catastrophic failure of the case.  I would not worry a bit about the casting remnants/features.

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