top end - time? parts? complexity?

[salgeek]

'04 250 Exc. 100+ hours on it.
Time for a top end - no doubt.

How much time will it take?
Is it best to pull the motor from the frame?
Teardown + inspection time est.?
Cleaning + reassembly time est.?

Parts needed? Tough to say without looking at the piston?

Powervalve cleaning - How? Is it really that complex to put back together?

How do I torque the 4 collar nuts on the cylinder base/jug? Will a 1/4 torque wrench with standard socket work? Looks like a tight fit. Do I need a crows foot?

Anyone know of a step by step guide beyond the manual?

thanks - Scott

 

[woodsy]

Wellll,, lets see,, nope - I have never done a KTM top end.. GUess I am not gonna be much help to you.. Maybe some off the cuff stuff would help:
I like to leave the engine in the frame. That way it isnt roling aroundwhile I am trying to work on it!!
Take the tank, seat, platic all off and hit that baby with the power washer,, Payclose attensioni tothe areas abaove the jug - claen now pays BIG later!!
I like pulling the jug with the head intact - it protrects the engine alot, right after removal you should cover the rid and open case area with rags,, That open bottomend is volnerable in this position,, WOrk above the cranck case with a good rag block stopp stuff, Remove the pistoin from rod using a puller - NEVER try to drive it out with a hammer. THis is very tempting but puts alot of pressure on bearings on the big end, Piston off, remove the smal end bearing abd clips while keeping the case coved real well, CLean ALL surfaces clean of any left over gasget material, Heres a hint, even if you didnt damage the old gasget can you reuse it and save some cash/// THe answer is no - put in knew.. Examine the port area in your just for chips in the Niclsil, Look carefully becasuse a simple little nick now is tommorros MAJOR MOTOR JOB!!! Look for aluminum smeared on wall of jug, if you have spots the way to clean them is with Muratic Acid - NOT WITH A HONE STONE!! Put acide on a q-tip and carefully work the spot - dont go beyond the original coating becsue thus stuff dont care what aluminmu it eats!!
Using a dial bore to check the taper of your jujg is a good idea!! THere is a good selection of good pistons out there.. THere is a new on the line that has Tephlon covering the lowerhalf.. Last I heard they are AWESOME!!! I beliefe they are aftermarket Japenese and qujite reasonalble tto.. Watch the ring gap on what ever you use, Also - Cometic Gaskets have givin us fits on fits,,, Vesrha fits much better,,, Of course, OEM works great too!

 

[Fred T]

I'm doing mine now. I recommend KTM vertex piston kit. It comes with rings, wrist pin and circlips. Buy a wrist pin gasket and base gasket. Thats it. DO NOT TAKE THE HEAD OFF WHEN REMOVING THE CYL. That will save you some money. Take the rads off, remove the cyl mounts on frame, take PV covers off carefully so yo can reuse gaskets. There is a clip on the ball push rod on a KTM PV and you pull that clip out and roll the ball to disconnect the cyl. Then you can fit a box end wrtench in there and remove cyl stud nuts.

 

[TCTrailrider]

One of the base nuts on the jug has a very tight fit. You need a thin wall socket or wrench. The bottle opener that comes in the KTM tool kit has the perfect size on the other end.

 

[bbarel]

For my old 98 250 my Caftsman wrench didn't, but I found a real nice Husky wrench at HD that fit in there. My 04 200 was even tighter and I had to grind the head of the wrench real thin.

 

[MWEISSEN]

One of the base nuts on the jug has a very tight fit. You need a thin wall socket or wrench. The bottle opener that comes in the KTM tool kit has the perfect size on the other end.

Shazaam! I always wondered what that wrench end was for! And here I was grinding down perfectly good wrenches to make 'em thinner.

When I asked the local KTM dealer was the torque spec was for the base nuts, he said it was "Gutentite". I used it, it seemed to work fine!

 

[bbarel]

Ok, but how do you get any leverage with a 3" wrench.