dangers of regular oil in a motorcycle engine?

[apopleptic]

OK, I know this is a stupid question, but I'm going to ask it anyhow so bear with me.
I have drained the oil out of my bike while de-greasing and then thought about checking for other leaks aside from my clutch oil seal.
I am wondering if I can use some cheap automotive motor oil and the old filter since I won't be riding it. I know that motorcycle oil is pretty specific due to the clutch being lubed by the engine oil, but I can't be paying for any wasted motorcycle oil which is quite expensive comparatively, especially since I have some new unwanted 5w-30 car motor oil since my newer car has been on synthetic since purchase. Can this motor oil be used for a 15 minute run to determine leaks? or will this be a catastrophe?
I basically only want to check to see if I need to order any more gaskets, I will not be riding the bike with this oil, and it will be drained right away. I'm thinking about taking the engine out so I can paint the frame, so like I said I don't want to waste the motorcycle oil. If I have to use the bike oil, I will be leaving it sit empty/disassembled until my new clutch oil seal arrives which just seems like a waste of time.
Thanks for your CONSTRUCTIVE feedback.

[Nessism]

Look on the circle label and if it says "energy conserving" don't use it. It can contaminate your clutch with low friction additives. Otherwise it will be fine.

BTW, diesel engine oil is great for motorcycles. No worry about the clutch, lots of zinc and phosphorus (high pressure additives), and much cheaper than motorcycle oil.

[cal_look_zero]

I went so far as to run rotella synthetic in my CBR. tired of paying $42 a gallon for my motorcycle blend that actually caused clutch slippage!

[Flaming Chainsaws]

If it does not say energy conserving on the back and is the same viscosity, it should be fine.

When you go out to buy oil that you will be using to ride, get Shell Rotella 15w-40 heavy duty engine oil. Works great. It's even JASO-MA certified!

http://en.wikipedia.org/wiki/Shell_Rotella_T

[SVSooke]

Another Rottela convert here.Much cheaper than MC oil but with all the stuff MC engines like.

[mike_of_bbg]

I'm less concerned about it being non-MC oil (I too use Rotella T dino 15W-40) than it being 5W-30. In all likelihood that will be API energy-conserving with anti-friction additives. Though, I doubt it would be harmful for you to use for a short period of time.

[pete]

We don't have Rotella here unfortunately, so I've gone with Castrol GTX Diesel 15w40...

[Johan Dubs]

I'm only here to agree with everyone on the Rotella 15w-40 Diesel oil. I switched to it at my last oil change. I have no complaints as of yet. It seems to work very well... I ran it in my truck too haha

[Whitedog]

Same here run Rotella T 15W-40 or Mobil Delavac 15W-40 diesel oil. Works just fine. Lots cheaper than motorcycle specific oil. Only bike that does not get one of the above is the '79 Sportster, it likes 50W racing or aviation oil. Runs smoother (if that's possible for a Harley) and leaks less at the push rod tubes.

[kawfeedave]

Last week a gallon of Rotella was $12 at Walmart, cheap enough to use for leak detection. Also, no reason you can't re-use it after you drain to replace gaskets. Install a new filter when you put in the new oil, run it to look for leaks, then leave the new filter in there and funnel the oil back in to the bottle to re-use after gasket placement.

Watch the engine temp if you're going to run the bike on the stand for 15 minutes. Try to do it outside so there's some air movement from wind, and put a strong fan blowing across the front of the engine/exhaust header area to carry some heat away.

[apopleptic]

Thanks for all the feedback. I've picked up the reccomended diesel oil and appreciate the savings!

[John S]

Newbie Here... just checking... my owners manual recommends using an SE or SF SAE 10 W-40 motor oil for my 83 GS 750 T. Just got the bike... haven't had to change the oil yet. But, when I do... can I use the Rotella T 15W-40 or Mobil Delavac 15W-40 diesel oil in my engine?

[cowboyup3371]

Hey John, read above. We are big converts to diesel oil since it's much less expensive and like Nessism says still maintains all the properties of "motorcycle oil"