KX5 drain plug repair

[KXsidecar]

Hey all,

I have a '91 KX5 engine that took a rock to the drain plug. Broke the drain plug and threads completely out. Is it possible to repair the case or do I need to replace? I can't post pic yet. Soon I will have enough post and will post a pic.
I loved this motor and want to run it again.

Thanks for any help,

KXsidecar
or Mike the Tall

[Friar-Tuck]

  Mike,
Cases are pretty pricey new, you may be able to find a decent used set,
But have you considered "Helicoil" or the like?
    There are several other "JB Weld type repairs. Usually a two part epoxy type deal.
 I think that would be great as a band-aid to finish a race however welding and re-tapping or helicoil type insert would be the best bet.
 (I am no expert by any means, but I have used the helicoil on a friends stripped drainplug and held great for three years and then the guy sold the bike.)
 http://www.youtube.com/watch?v=RFYa6sjhh_E&feature=related

http://www.amazon.com/Helicoil-5334-14-Thread-Thread-Repair/dp/B0002SRF4O

http://www.youtube.com/watch?v=RvmL0pEphQI
http://www.timesert.com/

[cbxracer30]

I've already had nickle size holes repaired in sets of cases. You need it find someone in your area thatis very skilled with a tig welder. This person should be able to fill the hole right in, but you will have to retouch the area with a file and or retap the threaded hole. For best results you should split the motor , the case welds best when its all cleaned up.The last time I priced cases ,and you must buy them as a set they were over $300. and that was at least 4 yrs. ago

[barryadam]

Mike,

Where are you located?  If you need a guy to weld repair that in S. California, I can give you the name of the guy who did mine.  He was in Vista / Escondido area.

Barry

[KXsidecar]

Thanks for the responses,

The heli coil is not an option. The rock(not sure it was a rock) busted out almost all the threads. I went to remove drain plug and the case/drain plug threads came with in multiple little pieces. All that is left is 1/4 of thread on 1 side and a jaged hole. It would be easy for some one to weld if I didn't need to drain oil again. I am thinking replacement cases are the only option.
Are all cases the same from year to year? Should I replace as a set? Are case halves matched sets?

I have never had my lower ends apart so forgive the dumbass questions.

Barry I am in Lost Angeles area.

Thanks for your help,

Mike

[stewart]

cases are in matched sets,,91 and up will interchange,,i have seen cases welded on drian plug spin shift drum bearings etc so i wont run a welded case

[barryadam]

cases are in matched sets,,91 and up will interchange,,i have seen cases welded on drian plug spin shift drum bearings etc so i wont run a welded case

In general, I agree with Stewart.  In my case (pun intended) , I had a guy who really knew what he was doing, the damage was limited, he used the proper heat sinks, and I inspected, measured, and matched the cases afterward.  I had purchased a brand new set - just in case (ha ha) .  But I would not recommend buying welded cases that are unknown.

So, it's been a month.  What did you decide to do?

[TheGDog]

My K5 some some kind of JB-Weld/Helicoil repair for its drain bolt.  (Was like that when I bought it.)

Works OK... but I can't seem to stop the super-slow drip leak when the drain-plug is tightened on.

I tried putting a (sorta thick-ish) copper washer in there... didn't seem to help.

I was thinking it might be helpful if perhaps I tried smearing a ring of the high-heat silicone around the underside of the washer so that when it's tightened down it can maybe seal better?

This sound OK to do to you guys?

[barryadam]

Depends on where it is originating from.  Helicoils do not seal themselves, so unless the gasket/washer is sealing on the cases outside of the diameter of the outer helicoil threads, that won't help.
Check to see if the helicoil is protruding slightly past the face of the washer/gasket surface as well.
Maybe there's some leakage in the JBweld to case area?
Is the gasket surface on the case perfectly flat and perpendicular to the bolt cenerline?

How about a picture?

I've switched all my bikes to a Zip-Ty drain plug.  It's aluminum, so the risk of damaging the case threads is greatly reduced.  Plus the bright blue anodizing provides a nice farkle factor.  With a skid plate to protect the bottom, it's all good.

[TheGDog]

I'll try to see about draining her oil and laying her on her side, removing the drain bolt and snapping a pic.

From what I remember when I inspect the previously installed (much thinner washer/gasket) you could tell that the matierial closer to its center hole was pulled-in from the tightening of the bolt pulling the head of the bolt down past the flat plane of the bottom side of the cases.

So to answer your question I DO NOT believe the installed fix-it solution provides a surface to tighten up to that is flush with the otuside surface of the case(s).

That is why I was asking if it should be no problem if I tried to use a bead of high-heat silicone gasket stuff around that new thicker copper washer i tried putting on instead.  My thought was that it could smoosh in there to seal whatever micro-scopic gaps there are. I figure it should only take the slightest amount applied to that washer.  I just haven't tried it yet because i wanted to find out if that gasket stuff would dissolve if it came into contact with the oil... and maybe move around and gum-up something internally and really cause me some heart-ache.