Preventing Thread Damage to the Lower Filter Cover Bolt

my 06 250f did this on the first or second oil change. didnt know what the problem was. i just ran a tap to clean the thread and sprayed it out with ALOT of brake cleaner. then put some oil in and drained out. never had another problem outta it.

i guess ill be puttin a bearin in as soon as i get my new 450

Is this mod required or suggested for an 09?

Is this mod required or suggested for an 09?

yes....pretty much all '98-09 YZ4xxF and YZ250F too

The ball is only wedged in the hole. Heat could potentially expand the size of the hole slightly. The edge of the hole has to be chipped over with a punch like in the picture to make sure it doesnt come out also. This chipped over piece could come off and go into the engine if not done perfectly and the ball could come out.

I know the factories use the ball method to seal parts like this but I would say they would use some kind of special press not just hammer it in and burr the edge over.

i did this mod without drilling the hole, i used the ball out of an old 3/8 extension and i used a punch to drive it in. ive had many hours on the bike, heat is not going to make the ball fall out.

Is this mod required or suggested for an 09?
Recommended for all YZF/WRF engines.
The ball is only wedged in the hole. Heat could potentially expand the size of the hole slightly. The edge of the hole has to be chipped over with a punch like in the picture to make sure it doesnt come out also. This chipped over piece could come off and go into the engine if not done perfectly and the ball could come out.

I know the factories use the ball method to seal parts like this but I would say they would use some kind of special press not just hammer it in and burr the edge over.

The plugs in your ignition cover and crankcase along the return oil passageway are only "wedged" in place, as are the plugs in the passages of your cam caps, and they are not staked. (see the plugs in the cam caps, above the cams, in the picture below) The expansion plugs in the cylinder block of your car/truck are only "wedged" in place. They are also not staked. The correct term is driven or pressed in, not wedged, and in each of those cases, the pressure behind the plug is pushing out against the plug. The plug in the filter well is being pushed into the bore by the oil pressure, not out.

The "burred" or "chipped over" mouth of the bore is staked. The punch mark at 8:00 o'clock in the picture is a better example correct staking, and the loose chip that resulted from the one closer to the edge was removed. If it had not been, it would have been trapped by the oil filter, like all the other debris found in that cavity.

The ball will not loosen when the case heats when installed correctly, because a hole that size will only expand by .001~.002" at most, and the ball itself will expand nearly half that much. Since the fit I recommended was .007" or more interference, what you fear is impossible.

While some of these plugs are inserted by machinery in parts where enough units are built to warrant setting such things up, but many are set by hand using customized drivers or standard punches and yes, hammers.

lobes.jpg

I just have to say, a fellow TTer had a few extra BB's and he mailed me both the right bit and 2 of the right sized BB's. Just one more example of what a great site this is.

Once again I'm baffled as to why anyone would even want to try something else when Gray's fix is so damn easy and quick?

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