KX Guru Racing

Yes, the kx500 has a 86mm bore and stroke.
That is why anything beyond about 10,000 rpm get's scarey on the K5.
I know some guys that run beyond that RPM but only for short periods of time.
So, if you do get a Carrillo rod you should be fine as long as you stay reasonable on your boost pressure.
What is reasonable

Reasonable is unreasonable to some. And selected engine parts.
But it's the revs of course that will do the most harm to the rod and big end. With the bigger turbo though the boost should be there when the revs are high. It's probably all, not going to be the best for the engine but what the hell, it might hold long enough for someone to get a video of me with the front wheel clawing the sky.

Well I kinda fancied doing a little machining today, I decided to make the spacers for the sprockets, the front spacer was just a little ring made out of a bit of stainless left over from making the exhaust it ended up 5.12mm when I parted it off the bar which is near enough to 5mm not to need to try to alter it. The front sprockets have a shoulder on the outboard side of them which I have machined off, a shit of a job, they are hard and I wrecked a few carbide tips over that! I have a 15t and I bought a 16t one too just so I could fit it if the bike can pull it, both are now ready to go. The rear I made a 5mm spacer out of a bit of 6mm plate, machined to size and bored and skimmed to 5mm, holes drilled to 8mm. Also I cut the back sprocket, 38t, to 4mm thick in the middle, from 6mm just so the sprocket nuts and studs can clear the swing arm ok, it means I need +3mm studs not +5mm.

Yep... some front sprockets are very hard...
I made my rear sprocket spacer for my kx from another old sprocket.
It's somewhat crude but it worked

That's a neat one. Mine will be visable from the sprocket side.

Cool.
Are you gonna home anodize it?

Little bit of progress on the plenum and intake tube. Got the two halves welded up and tidied up inside with the power file, then the two halves welded together and cleaned up. I had to cut another notch to tilt the tube downward at the back, it will clear the induction tube better and give more room for finish welding.

Then marked out and notched a hole for the tube to enter the plenum space.

Need to fit the access door now.

Sandblaster wrote:Cool.
Are you gonna home anodize it?

This build is going to take long enough without trying that. There is a anodised bolt on the oil feed but that was just because it was the cheapest I saw. I don't know where this build will go though so never say never.

Progress is looking great as usual.
Yeah, you have your hands full but you never know from the beginning the conclusion.
My bike continues to morph

Another thing I was concerned about was the tube coming from the turbo pulling one way or the other when welding, alloy is a pain, it distorts a lot when welding and it's certainly something to keep in mind. So I made a little gusset out of plate and folded a flat on the edge. It helped the stiffness and I hope it helps keep everything in place.

Then on went the W/M jet access door, with a little tab down to the induction tube just to add a little more strength to it all, also on this subject was the side-panel attachment point, I thought it would be good to extend this through the plenum to the other side to add stiffness to the structure. There will be a bit of force on the sides of this plenum. If I can get up to 15psi boost, it will be over 1000lbs(450kg ish) on the square area of each side of the plenum, thankfully of course it's distributed evenly over the whole side and not on any one point. Also this is going to be in the way of the end of the induction tube, so I waisted it but left a base on the end so I could get a generous blob of weld on it.

Then the application of a blob of weld, BZZZZZZZZZZZZT, ok another one BZZZZZZZZZZT

Next up I cut out a bit of plate that would more than cover the side and started to trim and fold it to shape pausing only to fillet my thumb, the saw kicked back and pushed a sharp edge of alloy at me, quickly, it wasn't the slightest bit sore, strange. It was a tricky job that needed a bit of time to get right, or near enough right to do, when I got as near as I could to right, on with the alloy glue! I have continued to adjust this welder as I go and it's going good again now. Even this 2mm plate, you can have a butt join with a gap and still weld it nicely without it blowing holes everywhere or sitting on top like bird sh!t. In this next photo you can see the folds and the end of the bar for the sidepanel attachment bolt.

And another view.

And with some clothes on.

Now there's a mistake, I sized that door to clear the access door then as I went along I thought it best to move the door further to the rear, I forgot about the sidepanel then becoming a problem.

So there it is for now.

Still loads to be done. The left hand side of the subframe has a bit of work to finish it off. And the piping for the W/M system, I am going to try to make a system for that so the pump cannot suck a air bubble. If I'm relying on a water pump to keep the engine from melting I better let it do it's job. I will make a small reservoir at the bottom of the plenum to trap the bubbles and put them back to the tank.

Yet another thing that's been in my thoughts is the carb, I have notched the frame a little around the shock mount but it still looked a tortured route for the air entering the carb, the carb sits in the wrong place. I am thinking the solution is to make a different attachment for the carb to the engine, do away with the carb rubber mount, and make a alloy one, matched to the carb mounting spigot and attach them both with a bit of rubber hose and two clips. The carb could then be mounted flatter and slightly kinked to the right hand side. But as usual there will be no hard copy plan for that and it remains to be seen how it might turn out. IF.... I had thought about this before I went with the idea of lifting the tank, seat and bodywork 15mm I might have seen this was not needed, OH WELL, never mind.
BTW, I will weld up that notches in the frame before completion. I think I will also put the wossner forged piston in and the KLX "R" intake cam I have and also I have a Carrillo rod on order too, 6-7weeks and that will be here. So for all that the engine will be out of the frame. You never know I might even paint it!!!!
If anyone wants to click on this it's at their own peril. It's my thumb post accident. Enjoy.
http://i1243.photobucket.com/albums/gg5 ... k3spsw.jpg