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Head Work

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I need to clean the head on my '98 WR 400. If I disassemble the valve train do I need to Lap the valves in when I re-assemble?

Also, does anyone know a source for rebuilt cranks?

Thanks

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Your 400 has steel valves right? If so I 'think' you lapp them but I'm not 100% sure, you will need to cut the valve seats and who ever does that will know.

I ended up just buying a new crank, as getting one rebuilt was only $75 cheaper and was faster and more reliable than getting one rebuilt.

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Thanks- Did you go OEM or aftermarket? If you went aftermarket, where?

I went OEM. The aftermarket I believe are simply rebuilt cranks and not newly designed and tooled components. But I'm not certain....

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If I disassemble the valve train do I need to Lap the valves in when I re-assemble?
You don't NEED to, but it's very cheap and easy to do and it won't hurt. Also, you don't need the valve seats re-cut unless you are having seating problems. Lapping will help determine if the valves are not seating properly.

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Only STEEL valves can be lapped. If you lap a Ti valve you will ruin them, it damages the hard Ti coating.

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Thanks for the info guys. I think I am going to part out the bike. I got it cheap and it need a whole new bottom end, crank, bearings, etc...

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