I need some help, PLEASE!!! 2003 YZ 450

My brothers YZ 450 was leaking oil around the clutch side crankcase cover. I replaced the gasket and put everything to gether.

The problem I ran into was, there was oil leaking out of the oil sopply line that bolts on to the bottom of the crankcase cover. I took it apart and cleaned it best I could and reinstalled the hose and bolt. I didn't have a torque wrench with me and when tightening the bolt, I broke it off.

My brother had done this before on a differant bolt, but fortunately it was a crankcase cover bolt and we were able to take the cover off and access the bolt with a pair of needle nose pliers. This bolt is in the crankcase it's self and has no access.

I'm thinking tap any dye is about the only way to get the bolt out. Any other suggestions? Does anyone have a used clutch side crankcase cover for sale? Help please.

Here is a link to the OEM fiche of the parts. The part I need is number 10.


i would use left hand drill bits and an easy out,that works most of the time for me.just make sure it good stuff like snap-on or similar quality

Left hand drill bit will probably spin it right out. What can happen with these fittings is after repeated torqueing, the boss at the end of the oil line can warp and not seal properly. Another common mistake, especially after a complete tear down, is that the wrong dowel is used. There are other dowels with this motor that are only 2mm longer and if used at the oil pipe junction, will not allow the boss to seat. Tdub

Yeah, it was the right bolt. I always put my bolts down in a circle representing the place they go in the case. I'd say it was a warped boss.

I'm just going to tap and helicoil. I have some 7mm helicoils in the garage. That would work, right?

since you broke it tightening it its prob not crossthreaded or anything so it should come right out with a left hand drill bit,drill and heli coil only as a last resort.

try the left hand drill bit first cause like said unless it was cross threaded it should roll right out. you could even try a normal drill bit in reverse to see if it will grab it and roll it out.

Bad news,

He already started drilling the hole out for the helicoil. What should I do?

if ya didnt drill to much then do the process above and rethread the hole with a tap, should be ok

He got about a quarter inch into the case. I was able to use an easyout to back the bolt out. But what should I do now? I was thinking just drill and helicoil, because he used a bigger drill bit than the bolt. He also drilled it off center, so I would have to use the existing bolt holt to center it up. Suggestions?

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