Head Work

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

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.

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

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....

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.

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

I'd get the seats cut and valves lapped. Why not go for the best possible seal while its apart?

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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