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The truth about honda valves

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In general, a good article.

One of the reasons given in the article for only intake valves having the problem is dirt coming through the intake. I question that, because the dirt does not go away with combustion. It would still be in the exhaust stream. Perhaps dirt affects the intakes more than the exhaust, but it is still in the exhaust stream.

I continue to think that there is a clue in the fact that it is the right intake that tends to go to zero. That might indicate an uneven cooling pattern in the head.

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You said to Replace with OEM or Kibble White Valve kit. My ? is, Kibble White is that titanium valves or the SS valves :) . By the way, nice simple explanation on why the valves are doing what they are. :)

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I have a set of Kibble White valves in my RMZ. They are SS. I do not know if they make a Ti valve or not. :)

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Fairly good article but......

1: Eating dirt or dust coming thru the air filter, bad seal on the air filter or air boot.

2: The profile of the cams intake lobes, very tall with a short duration, is causing the valves to slam shut.

3: Some aftermarket valve companies are claiming that Honda has poor grade of titanium.

4: Very high heat from unleaded race gas such as Ultimate 4, or lean carburetion.

Very high heat from unleaded race gas such as Ultimate 4,

This is a Very false statement. U4 has 4.2g/gal of lead. 6.2% Oxygen. It can run lean but the 04 CRF was real lean from the factory. The 05 is richer across the board and still has issues. IMO this statement can be discarded... all else seems be possibilities.

I still feel that it is a combination of can lobe design and spring issues at a certain RPM range. I wonder how the aftermarket Ti valves and OEM seats are holding up with all else being the same.

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my theory is surface rust developing on seats which in turn screws up the coating on intakes--air filters collect moisture after power washing & if valves are open , seats are prime for surface rust which happens in short time. Dust would affect all valves equally one would think so the right intake is propably heat related or maybe more likely to condensate moisture on its seat if in open position. I for one am guilty of putting bike away after washing without warming it back up---but now will protect air filter when washing/ warm bike up/ & leave it at top dead center[all valves closed] as preventative maintenance---

It would be interesting to find out if guys running with the bronze, berillium, or other non-corrisive seats of how their valve trains are holding out----

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You said to Replace with OEM or Kibble White Valve kit. My ? is, Kibble White is that titanium valves or the SS valves :) . By the way, nice simple explanation on why the valves are doing what they are. :)

the Kibblewhite valves are SS, but they are not out yet. but supposedly due out by at least May, I've even heard as early as mid March, but who really knows? :p

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So for those having problems, will replacing the entire valve fix it or will there need to be work done on the head and valve seats?

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From what I understand its a combo of things. For Ti vavles the seats that Honda uses are a bit to hard. So I think the best route is to change out to a softer seat and then go with a aftermarket valves. I am personally going with a RHC coated ti valve.

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good thing crfs don't have valve problems, otherwise someone may have to write an article explaining why they do :):):p:D

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I heard the knobbys are wearing off the hondas tire faster than some other brands does any one have a therory on why this is happening.

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The knobbies are wearing off faster because there is dirt getting in the knobbies.

I don't know why you guys are all making a big deal about the knobbies, I don't think this is just a Honda problem. Go check out the other forums, the Yamaha and Suzuki guys are wearing their knobbies too.

2000 miles and no knobby problems!

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In my area the water is soft, you must have hard water...thus your knobbies wear out quicker due to the higher concentration of minerals. If you coat your tires with a special lubricant, such as vaseline, it will help fight the hard water minerals from heating up your rubber compound and prematurely wearing the knobbies.

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That all may be true, but since Honda advertises more in the magazines, they won't report the knobby issues that Honda has that are way worse than the other brands and continue to rate them higher even though that everyone knows that they have this issue blah, blah, blah

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Honda puts Formula 1 technology in their knobbies, and you guys complain about wear. What do you want? 100,000 miles from them? I mean, there's just a certain amount of maintenance required.

As for the ice racing guy, I'll bet his knobbies were out of spec from the factory... He should have checked them before he started riding...

2,000 miles and no knobby problems!

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I checked my knobbies right after break-in and they were still in spec. Then I rode a bunch more and the knobbies went down to nuthin'! This is definatily a design flaw. Plus, there was dirt and dust all over my knobbies. I'm thinkin' class action suit here guys! Who's with me! (Tarzan Yell!!!) :)

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