Kawi KIPS exhaust valves woes

[roosteater]

Hey all,

I'm going through the top end on my 98 KX 250. It, of course, has the KIPS exhaust valve system. I've run into a problem that I've seen before, but I'm still uncertain how to conquer.

This is in regards to the actuator arm, which I think is termed a "pinion shaft." To fully disassemble the valving system so that all parts can be cleaned, one has to remove a small, gold-colored, aluminum, phillips-headed screw. This screw holds this pinion shaft in place. Once you remove the screw, the shaft pulls out and you can get the last remaining valve parts out of the cylinder.

However, as the screw is made of really weak aluminum, the phillips head strips very easily. This one already shows evidence of wear and is very tight. I'm fearful of just cranking on it as I'd probably just strip it out the rest of the way. So, I'm thinking of heating the area up with a torch to loosen it up a bit. If not, it seems that I'll be off to the machine shop to have it drilled out.

Questions:

1) Any advice on how to get this bugger out?
2) Why do these moron engineers use such a crappy fastener on a spot where the fastener is naturally going to tighten over time?
3) What can I do to avoid this crap in the future? I'm thinking of finding a substitute fastener with either a hex head or an allen head that won't strip out when I have to remove it in the future.

 

[David Trustrum]

1. Make sure you have many karma points built up, help little old ladies cross the road, pick up rubbish etc. Ok then apply a bit of heat. Use an impact driver (buy one if you don’t have one -they are cheap), but first give the bit a good smack with a hammer to shock the threads loose a bit, then use the driver. Then take it to the machine shop when that all fails & remember next time not to have impure thoughts about the neighbour’s daughter before attempting this type of work.

2. Because Kawasaki accountant hates you. It’s personal see?

3. Stainless Allen head, mmm.

 

[e.c.bert]

Yea So There! That's what I was going to suggest without using the torch though.

 

[David Trustrum]

What? including the bit about the neighbour’s daughter? Hey man you are physic!

 

[roosteater]

Thanks guys. You're right about the neighbor's daughter. I also like the stainless allen idea.

I'll heat and apply an impact driver tonight. The bugger is coming out!!! If not, I'll be visiting a machinist on Monday.

 

[Solid State]

Had a similar problem on a phillips head used to align the power valve shaft on my YZ. Gave it everthing I had with my best #2 phillips and nothing.

Tried penetrating oil and heat from a propane torch. Thought the philips was going to strip and just about gave up. Then, I tried a hardened steel phillips head bit and an electric cordless screwdriver. Put all my weight on it being careful to keep the bit straight, hit the trigger and BINGO!

The jerk from the tool broke it free. To re-assemble, I used a new OEM screw with lots of anti-seize.

Good luck.

 

[roosteater]

Ok...I picked up an impact driver. Three good strikes and it came loose. That thing is sweet!!! I'm glad I bought this tool. It had the carbide #2 phillips bit. It got very good bite and knocked it loose pretty easily.

I got the valves out, cleaned them good and alreay have the top end back on. Thanks for the advice.

 

[cr25096er]

yep those impact drivers do wonders

 

[David Trustrum]

Yeah just don’t go crazy tightening things with them, as you can imagine.

 

[OKKX'er]

I'm glad it worked out for you. I couldn't find my #1 bit for my impact so it tried to make the # 2 work, then the easy-out broke off. I had many, many, many, minutes of drilling to reflect on my good decision.

 

[David Trustrum]

Oh yeah when replacing impact bits, as they eventually fail. Don’t buy cheap replacements or worse yet screwdriver bits -as they will cheese sickeningly quickly.