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Valve removal/cleaning question

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I have the head off my 2001 DR-Z400S, (4000 miles)to replace the head gasket. Yep, it was bad, evidence of lots of leakage.

Anyway, looking from the intake port, my intake valves look worse than this -

http://home.earthlink.net/~natedog224/valve.jpg

Lots of black soft buildup on the back of the intake valves. I just bought this bike, and the air cleaner was dripping wet with heavy sticky oil. :thumbsup:

I don't think it needs a valve job at this mileage, and wonder whether I can remove/reinstall the valves to clean the back without a problem (re-cutting)

Actually, I'd prefer to clean them in place, if anyone has an idea how to do it. Can they be rotated in the seats without incident ?

Thanks

Bob

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Mine had less way less than 4000 miles when this happened

head1.jpg

Do yourself a favor and replace the valves, springs, retainers, seals, and cotters (keepers). I have bd kw's in right now but am going to swap out for a set of ferrea from rhc this next winter.

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Good luck cleaning in place. Yes the valves can be rotated if that helps any. No problem removing the valves. Just put them back in the same seats. You will need a valve spring compressor. This idea that over-oiling the filter carbons the valves is new to me. Not saying it is wrong, just never thought of it. Anyway, if there is a lot of carbon under the valves I would replace the stem seals.

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Mine had less way less than 4000 miles when this happened

head1.jpg

Do yourself a favor and replace the valves, springs, retainers, seals, and cotters (keepers).

Did that happen on a stock motor? That's pretty bad. I was not aware these engines failed like that so early. Is that common?

Bob

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I've been told that the two piece stock valves do not like to be ran with aftermarket cams? was this the situation?

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Good luck cleaning in place. Yes the valves can be rotated if that helps any. No problem removing the valves. Just put them back in the same seats. You will need a valve spring compressor. This idea that over-oiling the filter carbons the valves is new to me. Not saying it is wrong, just never thought of it. Anyway, if there is a lot of carbon under the valves I would replace the stem seals.

OK, thanks for the help. The seals being bad makes more sense to me. I was basing this, and got the pic from this thread, but no one really confirmed it there either

http://www.thumpertalk.com/forum/showthread.php?t=400348&highlight=air+filter+valves

I'll get a compressor locally and remove the intake valves and post the pic here today or tomorrow.

I'm trying to get back on the road ASAP, and will put off big replacement until this winter, maybe a big bore kit and all new valves, springs, etc.

Bob

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This idea that over-oiling the filter carbons the valves is new to me. Not saying it is wrong, just never thought of it. Anyway, if there is a lot of carbon under the valves I would replace the stem seals.

The other thing mentioned in that thread with similar deposits on intake valves was overfilling the oil. I'm starting to think this was much more likely, and oil was being sucked into the engine through the breather > intake boot.

I'm used to wet sump engines, like my older XR250R - was suprised when reading the manual that you need to check the oil immediately after running the engine, as it is a dry sump engine. If not, (or you don't know this), you will think it is low and overfill it (the oil leaks down to the engine sump over time when not in use).

Nobody would unknowingly overfill an engine by a quart of oil, but I can see how it could happen on this model if you never read the manual, and then simply check the oil on a cold engine. Then you ride the bike, and it all spews out the breather into the air intake. I would imagine it would smoke pretty bad, though.

Bob

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Did that happen on a stock motor? That's pretty bad. I was not aware these engines failed like that so early. Is that common?

Bob

Had just installed hot cams and had muzzy exhaust. The bike was 7 months old, yep one month over the warranty on the dirt model so I was on my own for repair.

Not very common but it has been known to happen, there have been quite a few broken valves documented here on TT.

I've been told that the two piece stock valves do not like to be ran with aftermarket cams? was this the situation?

Yep, hot cams were installed. But they were just installed a ride before so it wasn't a long term stress thing.

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The other thing mentioned in that thread with similar deposits on intake valves was overfilling the oil. I'm starting to think this was much more likely, and oil was being sucked into the engine through the breather > intake boot.

I'm used to wet sump engines, like my older XR250R - was suprised when reading the manual that you need to check the oil immediately after running the engine, as it is a dry sump engine. If not, (or you don't know this), you will think it is low and overfill it (the oil leaks down to the engine sump over time when not in use).

Nobody would unknowingly overfill an engine by a quart of oil, but I can see how it could happen on this model if you never read the manual, and then simply check the oil on a cold engine. Then you ride the bike, and it all spews out the breather into the air intake. I would imagine it would smoke pretty bad, though.

Bob

Nope, the procedure is to run 3 minutes and then off and wait 3 minutes. If not done properly you will not get an accurate reading.

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