2007 450 sx-f engine issue?

[canucklehead]

I found vertex piston for $190. It is high compression 13:1. I think it is also forged. So if you are certain this is the best route, I will splurge and skip the wiseco.

[tye1138]

Originally Posted by canucklehead

I found vertex piston for $190. It is high compression 13:1. I think it is also forged. So if you are certain this is the best route, I will splurge and skip the wiseco.

Yep, Vertex is the OEM manufacturer and they are based in Europe and made in Europe. So its a win-win, sure its more money then the Wiesco, but trust me you will be happier with the vertex.

[canucklehead]

i'm ordering parts today.

are the KTM cam chains prone to stretch/wear? (the Z400 cam chain was famous for stretch & rattle). it'd be easier to replace now, but a waste if I don't need to do it.

thanks.

[tye1138]

Originally Posted by canucklehead

i'm ordering parts today.

are the KTM cam chains prone to stretch/wear? (the Z400 cam chain was famous for stretch & rattle). it'd be easier to replace now, but a waste if I don't need to do it.

thanks.

I'd replace it just since it obviously skipped a tooth.

[canucklehead]

I will replace it. I should have a good look at the cam chain gears aswell. I can't find the shim for the valve that is at issue. Guess I'll be searching hard inside the crank case.

have you ever dealt with the coolant tube that runs inside the frame? It has a "T" at the top. I pulled the 2 rubber boots off of both ends of that T. Now I'm worried I won't be able to squeeze those press fitted boots back on. So I'm trying to figure out how the tube disconnects from the T. I think I'll replace the T, and possibly the tube.

I'm a dumbazz for not just removing the motor in the first place. I will before I reassemble it. I learn the hard way.

[canucklehead]

valve guide was broken aswell. valve was bent. I removed engine and when I got the exhaust pipe out of the way, it had a chunk of the valve guide inside. Still haven't located the valve shim. Wondering how many other pieces of broken valve guide and valve collets might be floating around elsewhere.

so on that note, should I be splitting case to go fishing for broken pieces? will they only be in the crankcase area, or could they float through oil passages to the clutch, tranny, etc..? this is ugly.

oops, forgot to mention. re-assembly of the cams is different. I need to press gear off old one and mount on new one, then check radial clearance of bearing and adjust. Intimidating. i might take that part to KTM dealer.

[tye1138]

Yea, usually the valve guides get destroyed.

Again, I'd send the whole head to a KTM expert, they will put in the new guides, they'll get everything setup for you properly and you'll be all set!

I'm trying to think of someone who specializes in KTM 4 strokes, all the guys I know are 2 stroke guys! EEK!!! I'll keep looking!

Ohh and in terms of trying to find those bits of metal, I don't see how they would get past the piston. They probably blew out the exhaust. You might need to send the cylinder in to get re coated, that can be done by millennium. http://www.mt-llc.com/

[canucklehead]

I have the head at our local guy that does machine work for the local KTM dealer. He doesn't get into the re-assembly, only the machining. So maybe I'll take the head to KTM to deal with the radial clearance of camshaft bearings. Can they also set valve lash at the same time? The lash is based on the cam position. Or does the pressure from piston being at TDC affect the lash at all? It'd be nice to just bolt head back on.

The valve shim and other metal pieces could fall down through the timing chain passages. On our 525 KTM (on my son's Outlaw quad), the decompression lever broke off the cam. I was super lucky to find the broken piece stuck inside the magneto. I will start my search at the magneto, and also plan to filter/strain the old motor oil to see what I find. I might remove clutch cover and other side covers to see what I can fish out. I don't want to split cases to go fishing, but maybe I need to do that. Leaving chunks of metal in there would be an expensive disaster.

I discovered I need to buy a special tool for the coolant tube removal. It runs up the centre of the frame, to a "T". That was a $100 mistake. If I'd have pulled the motor out in the first place, I'd never have destroyed the "T" connector.

I also wondered about the cylinder's Nikasil. It only needs to be honed. Or does that remove the coating?

[canucklehead]

5 pages later...it's probably only Tye and me reading this thread. but it is back together and running (finally).

so what about these oil pumps? I'm told it's only a couple of pieces that need to be replaced, and it's a quick, easy fix.