Tecate Cylinder Head question

[Frankencelery]

I was finally putting my new piston and cylinder in, which is done. However, the head has this material that won't come off. It FEELS smooth, but sure doesn't look like it is. I used a razor blade, some Scotch-brite, and even a wire brush, and this much remains. Will it still seal?

232399

[RIDE-RED 250r]

Is it material or just staining of the aluminum???

You might have luck with a die grinder with a gasket removal abrasive disc. The material of those discs are not unlike scotchbrite material. Use a VERY light touch with low RPM and this method should get the rest. But DO be careful with how hard you go after it, the die grinder and gasket removal wheel will take aluminum as well if you push the issue too much and that can leave you with a head gasket mating surface that is no longer uniformly flat and prone to leakage/blowing the head gasket.

But I would bet that head will seal if you do your part during installation to clean any and all residue from the head and cylinder deck with brake cleaner or a similar solvent.

[Frankencelery]

It might be just staining...That's what I'm starting to think anyway. If that's all it is, then I'll just put it back together... It shouldn't be a problem. Like I said, I can't feel anything on the surface.

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[atc007]

Glassboard or a fine sheet of sandpaper on a hard surface, and lap it in a figure 8 pattern, she'll be shiny and hopefully clean in no time. you will also know it is not warped.

[christph]

Glassboard or a fine sheet of sandpaper on a hard surface, and lap it in a figure 8 pattern, she'll be shiny and hopefully clean in no time. you will also know it is not warped.

My thoughts exactly. A sheet of 1500 grit sand paper on a flat surface. I use a plate of glass. I strongly recommend against using any handheld electric grinder. I don't care how careful you are, grinders have a way of getting away from you. If you make that surface uneven you're going to have sealing problems and make it leak compression, coolant, or both.

Judging by the pictures, it looks like you can use it as it is. When I do rebuilds the head usually has discoloration here and there. So long as they are not raised you should be fine.

[Frankencelery]

1500 grit? Wow, I would have used something like 400, but I admit I'm clueless! That's why I come here and ask questions like this.

It really does feel smooth, so I may just try to put it together as is.

[yaegerb]

good info in this post if I do say so myself....
http://www.3wheelerworld.com/showthread.php/173994-ATC-250R-coolant-leak-leads-to-enlightenment-Hand-Lapping-and-Time-Serts?highlight=leads+to+enlightenment

[Dirtcrasher]

I've used fine honing stones for decades. You can see he high spots disappear.

Stones with WD40 smooth out surfaces very well...

[86125m]

We use a brass wire wheel on a table grinder to remove a lot of our gasket material it works well . I think it would seal as it is however.

[RubberSalt]

If it's stained, then try some brake clean. If you can feel it, sand it.
Glass/Granite and some sand paper. Depending on how smooth it is, I'd smooth it out with at most, 600 grit.

I go with a wet/dry paper and a dish soap water solution. The paper cleans up fast and you can keep using it about 30 times longer. You will need some tape to hold it down!

I'd start with maybe 320, then 400 then 600. I haven't looked at the specs for the head on these as for smoothness, but i always step it up in increments.

The link posted by Yeagerb looks to be a good read and looks to be an improvement over the method I've used.

[Frankencelery]

Excellent posts. Thanks guys.