Oil filter bolt threads stripped...

[yernkie]

When changing the oil on my 400 the front (long) oil filter bolt pulled the threads out of the case. The bolt is fine, but the hole is shot. I tried a longer bolt and was able to get to a good thread but I am only able to get a quarter turn before it bottoms out. What should I do? Remove the clutch cover and helicoil, larger bolt, what? Need thoughts because I am heading to the dunes in 2 weeks.

[BlasterEaten250]

I drilled a larger hole and tapped it. Try not to go too much bigger however because it is very close to the wall of the engine case.

[yernkie]

What size did you drill to? Did you remove the clutch cover or just use a long bit and tap?

[400exmxrider15]

I recommend buying a Time-sert kit. Thats a M6x1.25. for about $40, you can buy the tap, drill bit, and 12 time-serts (from Napa) and you can do it to all on that side of the motor. The reason I took mine to my mechanic was because i stripped some out in the cylinder....

[yernkie]

M6 x 1.25? I thought it was M6 x 1.00?

[BlasterEaten250]

Originally posted by yernkie
What size did you drill to? Did you remove the clutch cover or just use a long bit and tap? I don't remember the size..I'm pretty sure it was just one size up from what is in there now. I kept the cover on and just put a shorter bolt in. It is only tapped in the cover and not the actual engine case.

[CJM]

The long bolt does go into the cases just so you know.

[yernkie]

Originally posted by CJM
The long bolt does go into the cases just so you know.

Yes, that is why I think I am going to helicoil it just to be safe. But is it M6x1.0 or M6x1.25?

[BlasterEaten250]

Originally posted by CJM
The long bolt does go into the cases just so you know. Mine doesn't after I tapped it and put a new bolt in. I didn't want to risk drilling a larger hole in the thin cast engine case and cracking it.

[CJM]

Wish i could tell you but I dont have any of those bolts handy.

Personally I wouldnt helicoil it, I have not had good luck with using them in soft aluminum and your already drilling the hole larger and cutting threads anyways. Buy a tap from a store and just tap it to next size. I got several 7mm bolts from home depot and the tap there iirc, no issues.

[yernkie]

Originally posted by CJM
Wish i could tell you but I dont have any of those bolts handy.

Personally I wouldnt helicoil it, I have not had good luck with using them in soft aluminum and your already drilling the hole larger and cutting threads anyways. Buy a tap from a store and just tap it to next size. I got several 7mm bolts from home depot and the tap there iirc, no issues.

Really? Think I could get a long enough 7mm tap so that I would not have to remove the cover? If it is stripped would I need to even drill to retap to 7mm?

[yernkie]

Originally posted by BlasterEaten250
Mine doesn't after I tapped it and put a new bolt in. I didn't want to risk drilling a larger hole in the thin cast engine case and cracking it.

Any problems with oil leaking from the clutch cover since that bolt also tightens down the clutch cover?

[CJM]

Realistically your not gonna get a helicoil down there either.

Heres really what you need to do:
1. Remove the case cover.
2. Tap out the smaller bolt in the cover.
3. Tap out the one in the case

Gonna cost you some time, money for the bolts, taps and gaskets.

Oh and next time you put the bolts back on-SNUG is how they should be tightened. Not cranked on like they are going outta style.

[BlasterEaten250]

Originally posted by yernkie
Any problems with oil leaking from the clutch cover since that bolt also tightens down the clutch cover? Nope. Not at all. It's been like that for a couple of years.

[yernkie]

Originally posted by CJM
Realistically your not gonna get a helicoil down there either.

Heres really what you need to do:
1. Remove the case cover.
2. Tap out the smaller bolt in the cover.
3. Tap out the one in the case

Gonna cost you some time, money for the bolts, taps and gaskets.

Oh and next time you put the bolts back on-SNUG is how they should be tightened. Not cranked on like they are going outta style.

I think that is what I will do. I have taper taps but no bottoming taps. Should I go with 7mm or up to 8mm?

[CJM]

Id do 7mm if you want to keep it metric or find an inch size thats very close to 6mm like 1/4.

Take into account the bolt head may not be the same small size as the others so be careful what you choose.

Me, Id try and find some hex cap screws since they have a small head and will fit on the case better maybe.

[yernkie]

I just tried something and it seemed to work. I had an SAE bolt that was just a tad bigger. I figured since the thread were trashed I'd try it. It grabbed some threads and tightened. I have to take it back out in a few days since I don't have an oil filter yet but I will reinstall that SAE bolt with some blue locktite and see if it will tighten. This won't be a permanent fix, but if it will tighten I imagine it will hold for the dune trip, then I will retap the hole once I get back and have more time. Cross your fingers for me....

[Honda4LifeWes36]

Sorry to go off topic here but with my oil cover, it leaks a little around the bottom of the cover. I always replace that little rubber seal that goes around it too and still cant get it! Not sure.

[yernkie]

Originally posted by Honda4LifeWes36
Sorry to go off topic here but with my oil cover, it leaks a little around the bottom of the cover. I always replace that little rubber seal that goes around it too and still cant get it! Not sure.

Mine too. It has done it the 5 years I have owned it. Its not bad, but I notice it when I am at the dunes because sand sticks to it. A buddy's 400ex does the same thing. Must be a Honda thing.

[Honda4LifeWes36]

LOL I've heard by over tightening the bolts on the cover will crush the O ring and make it leak. Everytime I do it, evidently it "crushes" it because I can NEVER get it right. Mine isn't bad either. Just can see a couple dribbles on ground if set running.

[CJM]

Never had that issue and I never replaced the O ring either.

Like I said before, snug is whats needed. I use a 1/4 ratchet, no extension and I choke up on the ratchet so my hand is on the head of it.

[yernkie]

Mine isn't that bad, but just doesn't seal right. My buddy fixed his by using a thicker o-ring he made. Seems to work fine. I may go that route once I get the hole retapped later down the road.

[yernkie]

Update: My hack job was getting to me so I decided to fix it right. I tracked down a clutch cover gasket Monday, pulled the cover, and retapped to 1/4 inch fine thread. I used a 1/4 instead of metric because I only had metric taper taps and wanted to use a bottoming tap since it is a blind hole, plus I had a fine thread 1/4 bolt that was the exact length of the factory bolt. The whole job took about 5 hours. 1 hour was cleaning off the factory gasket (I forgot to get gasket remover and wanted it clean), 1 hour was looking for the clutch arm spring that fell out in the yard while I was cleaning the cover (it was midnight), and 1 hour was spent drinking cold beer inspecting my work. All in all it should have been a 2 hour job, but oh well. It seems to have sealed up nicely with no leaks.

I even broke out the torque wrench for the filter cover and installed a new o-ring. Surprise...no leaks :)

Thanks for the tips. Tapping was better than a helicoil because I would have been afraid to drill out the case in that area.

[CJM]

Glad it all worked for ya :)