Maintenance adventures of Shadow and his futile battle against the cursed KX

[SachsGS]

Helicoils are horrible things and I believe they are stainless steel so basically non magnetic.Helicoils don't stand up well in situations where the fastener is frequently removed and reinstalled.Try flushing the gearbox with solvent.

What I've done in the past is chase the damaged thread with an Imperial thread tap (coated in grease to capture the filings). Sometimes you may have to redrill to the correct tap diameter.Your KX probably has a 10mm drain bolt thread so try a 7/16 NC tap - not perfect but it will get you back in the races.

[Shadow]

Fortunately not all stainless steel alloys are nonmagnetic. The only problem is, that I can't find a small enough magnet I could get pass the 5mm or so space that's immediately after the hole.  "Made for picking up tools and bolts from hard to reach places" my ass. All those tools get stuck on the small space.

Had some leftover fork oil that I used to fill the gearbox almost completely to try to flush the bit out but no luck.


Sachs, my first try on fixing the issue was using a thread tap but the threads were so badly stripped that there wasn't enough material anymore for working M10 thread. The helicoil seems to work fine, at least for the past dozen or so bolt removals and reinstalls.


Seems I'm starting to run out of options, unless you gentlemen might have any suggestions.

[SachsGS]

I know some of the cheaper grades of stainless are somewhat magnetic.Usually you can tap a stripped drainplug thread to an imperial size in between the existing metric thread and the custom heli-coil thread.

You probably have some "crud" on the base of your transmission and some old gas or solvent might allow you to dissolve it and flush it,and that pesky heli-coil tab,out.

[citabjockey]

if you do in fact get a coil frag to flush out of there, are your SURE that there is not another piece in there? Could have shattered into a few small pieces -- any one of which could cause plenty of further grief.

Only

One

Way

To

Be

Sure


split those cases. And then you are free to drill and tap to your hearts content to put a real replacement plug in that silly hole.

Just my $0.02 (and worth every cent).

[Shadow]

Well don't I feel stupid now. I was taking another peek up the drain hole and noticed that the end part of the helicoil hasn't actually snapped, it was simply bent to the side that it looked like it was.



True about splitting the cases though, would've been next on my list.

[Coop]

Hang in there man. We have all made mistakes and pulled moves we laugh about now.

This will make you feel better:

The very first time I was ever tearing a bike down (CR125) to split the cases I had the cylinder off (but piston still on the rod) and realized I didn't loosen the flywheel nut. Without even thinking I grabbed my air gun and spun the nut off, but in the mean time smashed the piston down into the case breaking a huge chunk off the piston  . That was almost twenty years ago but I still laugh about how dumb that was now.

[KX250]

Start by checking the route of your throttle cable, it could be a little twisted and cause the bike to rev.  Mine revs a little high at first and I know that's common but it settles down after it has been ran and warmed up to operating temp.  Something more technical, did you mess with the power valve? You may be off one tooth causing it to be more open which may cause the bike to rev higher.  As for the leak, is it weeping where the actuator goes into the motor by the counter shaft sprocket?  The in a rubber seal that sits down in there and that might need to be replaced.

[Shadow]

Thanks but those two things have been solved for a while already.


Coop, haha damn! That must've produced a few minutes of swearing.
Speaking of case splitting... The curse just hit my 125 while I was at the track, and either the shifter pedal or transmission went kaput. Will take a closer look at it after the weekend but I did notice the bike leaking transmission oil between the front chain gear shaft so at the very least its seal has gone bad. I might as well split the case though as it's not been done for the past 8 years. 
Might be a good time to learn to do that.