stripped threads

[Gerry B]

Hello,

I have a little problem. I have a 2000 YZ 426. On the oil filter cover there are 3 bolts that hold it on. Well, The bottom bolt is stripped on the case side and is leaking oil everywhere. What's the best way to fix it? Thanks!!

[misfitracer32]

If it is stuck in there then either drill it our or pull it out some how..Then rethread it.. Make sure you get all the metal shaving out though!! Well good luck!! PEACE OUT

Misfitracer32

02 YZ250F

[biznet1]

You may want to use a heli-coil. You can get them at some autoparts stores.

[Slowmotion426]

....helicoil worked on mine...

[Daz_426_02]

Depends on that is striped?? Is it the head of the bolt where the Allen-key goes in? Or is it the tread on the bolt or the thread on the case.

If it’s the tread on the casing then a helicoil would be best. If the tread is striped you shouldn’t need to drill it out get a good pair of vice grips on there and pull it out while turning it and it should come out. Replace the bolt as well any way.

If it’s the head of the bolt try the vice grips again…

Good luck.

[WheelsUp]

Be extremely careful on that one. I'm not positive on the 400 series engine, but on the 250, the bottom hole goes all the way through and into the case.

Look at the bottom of the filter compartment. If there's a small hole a half inch or so back, then it probably does.

My buddy discovered that when he was having a hard time getting the screw in. It must have been hung up on the O-ring, even though it appeared to be clear. We thought the threads were fouled, so he shot some WD40 into it to clear them.

When no WD40 came back out, we knew something was up.

Pulled the case drain and voila... WD40.

Needless to say, you do NOT want any chips to get in there

The risk of damage is minimal, as the case oil is pumped back to the frame, where it has to pass through the screen before hitting the primary oil pump, but chips from threading or HC installation could foul the return pump.

I think this is more than a 2-beer job.

[Ga426owner]

There is plenty of info on this - do a search - TymeCert is better fix than helicoil -

?

[grayracer513]

A Time Sert might be tough to use on that particular hole because of it being recessed. Time Sert require a little extra space because the tool that re-cuts the threads also spot faces the top of the threaded hole. But as it's set up for a shouldered bolt, there could be room.

I would definitely remove the cover to fix it though, so the debris could be dealt with safely. And run a die over the threads on the bolt to clean it up, or replace it with a new one.

[Gerry B]

I was thinking of just drilling the hole a size bigger then re-tapping it. The hole that I stripped is the filter drain screw on the cover. It's the bottom bolt of the cover. behind that bolt is an O-ring.

[grayracer513]

Your best repair will be one that restores the threads to their original size. Use either a heli-coil, or, if possible, a Time-Sert.

[redright]

Just for future reference, invest in an inch pounds torque wrench. Your manual has all of the torque specs so this won't happen again. Just a suggestion.

[Gerry B]

I just spoke to the dealer and they told me that I had to replace the whole side case because I couldn't put a helicoil because I would be blocking some oil passages with the helicoil on that bolt. Is that true?

[grayracer513]

The hole in question has a passageway drilled into it at a near right angle from the oil filter cavity. The intent was to provide a means of draining the filter well, presumably so the oil in the well would not run down the side of the engine when servicing the filter. It does that anyway because scheme doesn't really work. If you think about it at all, the passageway could not be critical to the engine since there's a bolt in that hole when the engine is running.

Lube oil flows into the filter well from the oil pump through a large passage in the floor of the well. You can see it with the filter out. Then, it flows through the filter and out the passageway in the filter cover to two oilways in the case cover, one goes directly to the crank, and the other splits off and feeds the top end and transmission. If you remove the cover, you will find that the bolt hole where the allen bolt lives just drops out into the clutch case.

[Gerry B]

Thanks Grayracer!

I thought so. Thanks for the great input! I will be using a timecert. Thanks again.

[Ga426owner]

The hole in question has a passageway drilled into it at a near right angle from the oil filter cavity. The intent was to provide a means of draining the filter well, presumably so the oil in the well would not run down the side of the engine when servicing the filter. It does that anyway because scheme doesn't really work. If you think about it at all, the passageway could not be critical to the engine since there's a bolt in that hole when the engine is running.

Lube oil flows into the filter well from the oil pump through a large passage in the floor of the well. You can see it with the filter out. Then, it flows through the filter and out the passageway in the filter cover to two oilways in the case cover, one goes directly to the crank, and the other splits off and feeds the top end and transmission. If you remove the cover, you will find that the bolt hole where the allen bolt lives just drops out into the clutch case.

Grey correct me if I am wrong but the "hole" in question gets metal shavings etc...that get into the threads of the allenhead bolt - as you remove it to get to the oil filter. The junk causes the threads to stretch eventually causing the bolt to strip out the case - I always plug this hole and ZIPTY Racing has the kit to do this - ?

[grayracer513]

I've heard the theory (or fact) about debris from the filter well invading the threads of that hole when used as a filter drain. It was one of the first tidbits I picked up off of TT, in fact, and it's another reason I don't use the lower bolt that way. Instead, I stand the bike up straight (sort of. the stand I use actually leans to the right a little) and use a tin foil "bib" to direct most of the oil into a drain pan (another trick from a TT member) and just take the cover off.

As a result of that practice, and the fact that the previous owner apparently didn't drain the filter through the bottom bolt, the threads on the allen in my 250F have always been nice and smooth. The 450 was a little rough when I got it, but I cleaned up the threads on the bolt, and the threads in the case are beginning to smooth out.

So I think you're right. I'll bet the Heli-coil or Time Sert will block off the hole, too.

[biznet1]

I know this is not good practice (ok, it's redneck), so I may get beat up on this one, but mine stripped too, and this is what I did. I bought a new 6mm bolt about 5 threads longer than the original, tapped the hole a little further, and walla! It holds just fine. I didn't have to drill the hole further, and I couldn't see anything that it might interfere with, so yes I did it.

And yes, you will find many rolls of ducktape laying around in my shop ?

By the way, not duct tape, that is used by heating and air guys. Ducktape is for everything else.

[mj2412]

Hello,

mine thread stripped too and i tried different things to repair it. First i used one long helicoil and tried to drill the small hole from the oil filter in the helicoil, but no chance. The helicoil is not able to drill. Then i took the helicoil out and took 2 shorter helicoils. I put one to the end of the thread and the other one at the beginning of the hole. Now the part with the hole form the oil filter is no helicoil and because of the same thread for the helicoil it is no problem for the bolt. It works great for me.

Martin

[MotoGoalie]

I guess I can chime in too. Mine was stripped the day i bought my used 03. Thing is, just the bolt was stripped down. I went and gave mr. Yamaha $8 for another hIgH quality bolt (I didn't use some old hex head bolt as its somewhat tapered and leaked quite a bit). Anyhow, the threads in the case werent too buggered up as it torques down properly.

That is the one big thing about these bikes. The torque specs seem to be very very delicate compared to stuff I'm used to working on ....cars, trucks and XRs. You really must have a 1/4 torque wrench to do anything properly on these bikes.

Didn't know that about the metal shavings but I suspected as much. The first time I changed the oil and i discovered this stripped out bolt, it was full of garbage as was the filter ? I haven't seen anything significant like that in the 2 oil changes since.

[Ga426owner]

I've heard the theory (or fact) about debris from the filter well invading the threads of that hole when used as a filter drain. It was one of the first tidbits I picked up off of TT, in fact, and it's another reason I don't use the lower bolt that way. Instead, I stand the bike up straight (sort of. the stand I use actually leans to the right a little) and use a tin foil "bib" to direct most of the oil into a drain pan (another trick from a TT member) and just take the cover off.

As a result of that practice, and the fact that the previous owner apparently didn't drain the filter through the bottom bolt, the threads on the allen in my 250F have always been nice and smooth. The 450 was a little rough when I got it, but I cleaned up the threads on the bolt, and the threads in the case are beginning to smooth out.

So I think you're right. I'll bet the Heli-coil or Time Sert will block off the hole, too.

The tyme cert works better - and it does seal the stupid debree hole.. ?