Bent valves

9 replies to this topic
  • CanadianWR450

Posted November 19, 2012 - 02:49 AM


My bike jumped timing, and the piston contacted the valves. I got off very lucky stalled while on a nasty down hill, and I was going very slow. Hit the Estart and it made bad, bad tried it again after that.
Took it apart and the timing was completely out to lunch, bent valves (intake took the worse), but no other damage! You can see where the valves "cleaned off" the carbon on top of piston, and some very, very minor contact impressions on piston itself once we cleaned it. I have to say, I'm pretty impressed with the Athena forged pistons in their big bore kits.

So, I need valves, and get the seats redone, timing chain (Timing chain was the culprit was bad).

OEM valves, or SS valves? If SS Kibble White still the best going?
I only trail racing, no track, etc.

  • MANIAC998

Posted November 19, 2012 - 04:47 AM


Sounds like you did get off lucky!! From what I've heard, you will lose just a smidgen of performance from installing the SS Kiblewhite valves. Barely enough to notice. And if that's the case, I say go for it!

  • CanadianWR450

Posted November 19, 2012 - 05:07 AM


Thanks Maniac, lucky indeed, and I'm going SS valves...
Anyone have a opinion as to pro-X vs Kibble White?

I'm REALLY impressed with the Athena big bore kit....the cylinder looks like the day we put it in after 100 hours on it! The forged piston as mentioned hardly has a mark on it from hitting, you can barley see the slightest of impressions from the valves.

Thank god I only tried the estart and heard the horribly sound instead of it jumping timing under power on the uphill portion! Timing chain will now be changed every second season at least no matter what, and maybe every season depending on how much riding I get in.

  • Just_a_trail_rider

Posted November 22, 2012 - 09:42 AM


WHy not OEM valves. They last forever, don't they. Why do something different?

  • CanadianWR450

Posted November 24, 2012 - 02:12 AM


Simply a matter of $$$, and I certainly won't notice, or need, any performance drawback of going SS over titanium.

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  • MANIAC998

Posted November 25, 2012 - 04:31 AM


If it's a matter of money, I believe your going to find that sticking with OEM is going to be cheaper than switching over to SS.

  • CanadianWR450

Posted November 25, 2012 - 05:23 AM


KW SS valves - $48 each - $240.00
Spring Kit - $288.00
= $528.00

Titanium valves - $156 each
= $780.00

Now, the titanium valves are wisco, and I have not priced OEM yet.
Once I do, if they are a lot cheaper then aftermarket titanium, I have no issue going oem valves. The current set lasted a LOT of hours.

  • MANIAC998

Posted November 25, 2012 - 07:58 AM


I forgot how expensive parts are in Canada! Here in the States, OEM valves are about $50 a piece.

  • CanadianWR450

Posted November 25, 2012 - 10:51 AM


Welcome to Canada, or as I like to call it "How can we tax and overcharge you ada"

  • revyrider

Posted November 26, 2012 - 07:25 AM


I buy most of my parts & gear online through Ebay etc.If you make sure they are shipped with US postal service they rarely go through customs checks & NO Canadian taxes are charged!Much cheaper


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