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Exhaust valve wear with only 60hrs

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I have a 05 450x with approx 60 hrs. I checked the valves. The intake valves were perfect, no wear. The exhaust were suppose to be .011 and I found them to be .003 and .007. I was shocked because I have taken exceptional care with air filter changes, etc. It starts easy, runs great, idles great, etc. Am I a fool for keep on running it and waiting for it to run poor, or should I get it into the dealership. I've heard that shimming the valves is only a temp fix and it will be back in the shop soon to have the valves replaced.

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Do you have prior measurements showing that the exhausts were in spec?

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Everything on the bike is stock, the only mistake I made is not measuring the valves eariler so I would have a base measurement. I didn't know if I would damage the engine by continuing running the engine and taking another

measure in 10 hrs.

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This is very odd, as the majority, including me, lose an intake valve while the steel exhaust valves stay in spec... Now, most people have modded their X to a big breathin' gas suckin' cooler runnin' machine....Not a lot of stockers out there with owners on the forums, you know? My early hunch is that a stocker runs so hot, as to actually burn up the exhaust valves, before grinding away the heat-treated coating on the intakes. Does this sound like a possibility?

Since you're losing your exhaust valves, maybe due to extreme heat, instead of fine dust grinding, you probably have some more miles available.

When the intakes go, its very fast, 50-100 miles maybe.

paul

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Without a prior inspection we don't know where you are at but usually the inlet valves go first,so if they are right then the exhaust is probably where it came stock or very close to it as there has been no change in performance.I would at least shim the lot write down the figures and ride.

Actually that is what i would do.

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Hey threecrf's, don't go digging in and shimming anything yet. You're not at TDC bud, no way.

What you're showing is highly unlikely, and nobody I've ever heard of had had such a weird combination .

Check this :

http://i86.photobucket.com/albums/k98/rhansen450x/ValveClearance-Marks.jpg

Unless you swallowed dust or dirt there's just no way, and to think that just the exhaust and not the intakes would be affected make no sense at all. Check them again, making sure youre on the right mark per the photo, put a wooden dowel in the plug hole, whatever you can to be sure you're at TDC.

Also, you need to get that jetting fixed. You don't need to do a big list of mods, but a JD jet kit, opening the airbox, and bypassing the smog device will do wonders for your bike, and as pointed out your bike will run noticeably cooler.

Let us know how it turns out. Doug

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Am I a fool for keep on running it and waiting for it to run poor, or should I get it into the dealership

And no, you're not a fool,and absolutely don't take it to the dealership.

These bikes do not run as well as you describe yours with valves that far out of whack,ever, especially the starting right up.

A lot of guys have never checked theirs,and that's okay. When they need valves shimmed or replaced these bikes let you know, and the way they do it is they don't want to start. You're not hurting a thing either, the valve seats should be re-cut anyway anytime valves are replaced.

Your bikes valves are fine or it wouldn't be starting so easily and running well.

Wait until you get that jetting squared away, then you'll really be happy !:applause: Doug

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Hey threecrf's, don't go digging in and shimming anything yet. You're not at TDC bud, no way.

What you're showing is highly unlikely, and nobody I've ever heard of had had such a weird combination .

Check this :

http://i86.photobucket.com/albums/k98/rhansen450x/ValveClearance-Marks.jpg

Unless you swallowed dust or dirt there's just no way, and to think that just the exhaust and not the intakes would be affected make no sense at all. Check them again, making sure youre on the right mark per the photo, put a wooden dowel in the plug hole, whatever you can to be sure you're at TDC.

Also, you need to get that jetting fixed. You don't need to do a big list of mods, but a JD jet kit, opening the airbox, and bypassing the smog device will do wonders for your bike, and as pointed out your bike will run noticeably cooler.

Let us know how it turns out. Doug

This is correct. I had assumed you were on TDC. Use the timing marks on both sides of the engine, as described in your Clymer manual. When 180deg out from TDC, the exhaust rocker arm is tight, when correctly on TDC, you should be able to actually rock the rocker arm by hand. Check this for TDC insurance.

paul

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Threecrfs - As noted above, make sure you're using the right timing mark. It's very easy to use the wrong one and you'll be 60 or 70 degrees away from top dead center. It drops your exhaust valve clearance down into the range you are experiencing.

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When 180deg out from TDC, the exhaust rocker arm is tight, when correctly on TDC, you should be able to actually rock the rocker arm by hand. Check this for TDC insurance

Pauls right. You are 180 degrees or so out, that's why you can only get that little .003 gauge in there, giving you the false reading.

Incidently,gprodick had the same sort of thing happen thing happen,and hooked us up with that photo I posted.

This news should be making your day ! Doug

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Yes. This did happen to me and I felt pretty silly, but damned relieved.

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Now that you know you don't have to do anything to your valves, do yourself a favor and buy one of these :

http://www.crfsonly.com/catalog/product_info.php/manufacturers_id/112/products_id/1093?

If you just do nothing but follow the directions in the box, nothing else, you will be rewarded with a bike that runs a lot cooler, and while you do pick up a little power it's more linear and smoother as it comes on. You won't be sorry.

If you have an evil smog device, here's a great article by skoot22, where for the price of JB weld you can eliminate it, have your bike appear stone stock to the Nazi's, and be done with decel popping :

http://www.crfsonly.com/forum/viewtopic.php?t=9509&highlight=

I was keeping track of how many people gprodicks photo has saved from panic attacks, and I think we're at 6 or 7 !

A Clymer manual is really nice, the stock owners manual isn't bad at all, and this article, though for an R , is excellent, the job is identical even though it's for an R :

http://crfsonly.com/howto/450r/valve-check/450r-valve-check.php

Just pay close attention to the photo showing which mark to use.

Doug

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Doug, I'd like to take credit for those photos, but, honestly, somebody else posted them originally.

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My 2006 CRF450X had perfect intake clearance but very tight exhausts from the factory, I adjusted them before I even put gas in the bike. After 10 or so hours the exhausts tightened up slightly again. Since then the valves have always stayed perfect, no more adjusting required.

That one photo of the 3 punch marks on gear where you set your TDC would be very confusing. I am pretty certain mine does not have any additional marks on that gear.

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That one photo of the 3 punch marks on gear where you set your TDC would be very confusing.

My X had all 3 of the marks, and it doesn't look confusing to me, but hey...

Not as confusing as thinking you're at .003 clearance on your exhaust valves with a new bike !:applause: Doug

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Thank you everyone. When checking it with a dowel pin I found I was not

on TDC (The pic was great). The valve clearance are in spec. I am feeling alot better. I appreciate the advice.

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Thank you everyone. When checking it with a dowel pin I found I was not

on TDC (The pic was great). The valve clearance are in spec. I am feeling alot better. I appreciate the advice.

Use a straw instead of the dowel pin. I had a dowel break once and had to go fishing. Boy did I feel like a fool.

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