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Most of you change your own oil like I do. I found this last oil change that I did and around the filler cap was wet. So I wiped it off and it was oil. I thought I didn't tighten the oil filler cap tight enough, I checked and I did.
Tonight I changed my spark plugs and I noticed that it was wet around the oil filler plug again. My dealership was still open and I called them and told them about it. They said to send a picture. So they said it could be loose, a bad O-ring or it's cracked. Upon further inspection, I found the cap was cracked. I sent another pic and they said they are going to order a new one. So be careful tightening this plug. The service manual says tighten to 7.4 lbs. This cap is cast aluminum. In my opinion and my experience in being over a 20 year machinist, this cap should be machined out of a solid piece of aluminum. It would be stronger!!!
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interesting!

the oil fill cap on my two Vstar bikes are designed to be put on with fingertips

I always feel a bit insecure doing that, and use a crescent wrench to nudge it down just a bit, and to take it off

going to stop doing that now - would have been worse if the engine case cracked!
 
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Most of you change your own oil like I do. I found this last oil change that I did and around the filler cap was wet. So I wiped it off and it was oil. I thought I didn't tighten the oil filler cap tight enough, I checked and I did.
Tonight I changed my spark plugs and I noticed that it was wet around the oil filler plug again. My dealership was still open and I called them and told them about it. They said to send a picture. So they said it could be loose, a bad O-ring or it's cracked. Upon further inspection, I found the cap was cracked. I sent another pic and they said they are going to order a new one. So be careful tightening this plug. The service manual says tighten to 7.4 lbs. This cap is cast aluminum. In my opinion and my experience in being over a 20 year machinist, this cap should be machined out of a solid piece of aluminum. It would be stronger!!!
View attachment 91045 View attachment 91046
I was the first in the Southeast to get mine and had run into that problem LONG ago. I posted something about it stating back then that the torque spec for that cap was incorrect. I was using a torque wrench putting it on and mine snapped the top flange of the plug off LONG before I reached the reported spec.
That plug is made out a cast aluminum (poor design) and you really need to stop at about 2.5. Fortunately I was able to extract the threaded portion and not have it drop into the crankcase. That would’ve really ticked me off.
What I did do was to get a regular automotive hex head oil plug (has a flange top) with gasket to have as a backup just in case. It was silver so I had to paint it black. I used it until the new part came in.
Ever since I started torquing it at less than HALF the book spec, I haven’t had a problem NOR have I had any leaking.
 

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after reading about this, I think from now on I will put mine on finger tight (with the flat tabs on my bikes)

and make it part of my morning pre-ride check to test it with my fingers to make sure its not loose
 

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after reading about this, I think from now on I will put mine on finger tight (with the flat tabs on my bikes)

and make it part of my morning pre-ride check to test it with my fingers to make sure its not loose
Just to be clear @KCW, it’s the crankcase plug that’s the issue (cheap construction). The one in the main oil reservoir is plastic, but definitely more robust material.
 
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