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OK, now I'm confused...

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After reading all of these valve posts on here recently, and getting ready to do my valves for the first time this winter, I have found myself to be a little confused...

It seems like everyone is either saying SS valves are junk and yamahas can't handle them. Only use Ti valves.

OR

Titanium valves wear out way to fast and are way too expensive, so you should get SS valves.

Well, I'll admit I'm pretty conservative when it comes to revving out the bike although I'll spool it up every once in a while. I'm not made out of money either, so price is an issue.

BUT I can get OEM valves ($45-50) for just about the same price as Kibblewhite SS valves ($40). Aren't the OEM ones Titanium? Is the only benefit of the SS valves the (alleged) longer life?

Any sage advice from those wiser than I?

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Ok, who is everyone? Where is this info coming from? how many people on TT have posted that their bikes blew up mysteriously after changing to SS valves, because unless people who HAVE DONE THIS are posting this information, I don't believe it. And I'll be the first to tell you all if it happens to anyone I know or myself for that matter.

The head has not changed in 10 years, people have been putting in SS valves for 10 years, no one I know has had a head fail because of ss valves (unless they dropped one but that'll happen even more frequently with Ti valves lol).

Talk to an experienced engine builder and get their opinion if you want, but none of my friends or myself have had issues with SS valves in a yamaha head.

Eric Gorr has done quite a bit of work for people I know and myself, HE actually recommends SS valves for longevity over Ti valves and he's one of teh best engine builders around. Some may argue that but I've dealt with him numerous times and he is VERY good.

I doubt Kibblewhite would produce SS valves if they take out your head, it would be pretty bad for their business if the forums filled with bad news about people's bikes blowing up.

Kibblewhite valves are also one piece which means the tip will not break off nearly as easily as on a two piece valve like Ti valves are.

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just use all OEM.

replace the springs and seals as well

kibble n bits require their springs which are spendy and dont let the bike run the way it was meant to run because of the extra weight.

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the weight is negligible, the right springs handle that for you. Unless you race MX2 you aren't going to notice anything. My 400 bored 420 pulled on any modern 450 with 30 less cc and it ran SS valves...for over 200 hours without an adjustment.

Ti may be cheaper to start but SS valves last a whole lot longer, so when you're doing another set of Ti valves, I'll be riding, and when you're doing yet another set of Ti Valves, I'll be riding and then we'll be even on the dollars spent, then maybe, i'll have to shim when you're on your next set of Ti valves.

And if I ever have to replace them, I'll have my springs and my SS valves will be 32 whilst your Ti valves are 50+

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This is what I'm talking about.

So if OEM Ti valves are about the same price as SS valves, and I'll need to replace my OEM springs if I stick with OEM. Will I need to replace the springs each time I replace the valves if I go with SS?

Looks like a full OEM rebuild with springs, guides, and valves is round $350 ish, where a KW SS "conversion" would be around $400 for the valves, spring kit, plus however much for the valve guides.

So the cost is pretty close to the same, unless I'm overlooking something. I like the idea of more durable, but the whole added weight argument seems plausible. Even if the springs are adjusted to keep up with the engine, I would think the extra mass of the valve hammering the head would cause the seat to wear faster? Maybe it is negligible...

I'm not planning on building a crazy high MX monster, I'm just looming for the most reliable option for having fun in the woods, trails, and even the occasional MX track. Since the prices are looking pretty close it's just down to which will work best.

I have another thing to add to the question. I'm considering a 290 kit, if that shows down the RPM a little, wouldn't the extra weight of the SS valves be less of an issue?

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Those are definitely interesting. I would have never thought of "golf balling" a valve but it makes sense to me! Too bad doing all 5 valves would be $500, and that's without springs or anything else. Although if I was going to go with solid TI valves, i would definitely go with those because they're a good $30-40 cheaper than their competition.

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Pro's of Ti Valves:

-Light weight

-Cheap

-Last long with proper air filter maintenance

Pro's of SS valves:

-Last long and can be shimmed until there is nothing left of the valve seat or valve

Con's of Ti valves:

-If air filter maint is not done properly the coating can prematurely be worn off and cause excessive valve wear

Con's of SS valves:

-Considerable heavier when you factor in the possibility of 12,500 RPM!!!

-Valve springs are much stiffer to be able to control valve float due to the extra weight which reduces maximum rpm, slows acceleration minorly, and motor builders OTHER than Eric Gorr will report cases where a rider hard on motors have actually beaten the valve seats into the head from the stiffer springs/heavier valves.

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Well, I wouldn't call aftermarket Ti valves cheap!

I was a little worried about the seats getting slammed with the heavier valves. It makes sense, so I'm not surprised that some people have reported it.

What do y'all think of the weight of SS valves / slower RPM combined with a big bore kit like a 290?

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Well, stock Ti valves are cheap when you get the kit on e-bay for $300 that includes everything.

I don't really get what your asking about the ss valves having to do with a 290 kit?

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Not to confuse you more but check out these!!

http://www.williamsmotowerx.net/valves.htm

Hey Swede, I clicked on that link you gave, and I see this:

● your valves should be replaced every 20 hours, replace them with performance and confidence with Williams Motowerx

O.K. - I understand that is a suggestion; but look at the ad closely, that means any valve (the way I'm reading it), should be replaced at the 20hr mark. Not just his valves, but any valve used I would think; though I feel that design would last longer. That design is really unique, and just makes better sense in motors pushing 12~13G.

Now if the valves should be replaced every 20 hours, how come everyone is getting 80 to 120 hours before their first adjustment to the shims, and then go on to get 200+ hours out of them without dropping one from fatigue failures when they are only suppose to run them twenty hours to begin with?

I don't know, maybe I'm just imagining everything I read on TT, or maybe; just maybe, we are all getting lucky and that was a typo in the ad :worthy:. From the way that is advertised, that would be the equivalent (almost) of us running a stock piston only 10 hours and pitching it, instead of the known 50~60 hours of good use we know we can get out of them. Now I am the one that is confused, because that is the first advertisement I ever saw, in which it is recommended that valves should be changed out at twenty hours - or lets just say, that early.

How come everyone always tells me about those kinds of hours (80~120 hrs. before a first shim adjustment is needed), yet someone that has twenty plus years experience in the industry, is advertising that the valves should be changed out at 20 hours? Now I don't feel so bad about the hours I'm getting out of Ti valves, matter of fact, I'm somewhat rather :thumbsup: joyous and overly happy, because no one on TT EVER told me to replace them at twenty hours, they told me to check clearances every 20 hours or so. Now I come to find out that a valve should be tossed at twenty hours of use - What to believe, What to believe :ride::worthy: :worthy:. I just know that I have used valves more than twenty hours; but to find out that there is an actual service limit recommendation that short - What's going on here?

I'm really considering his valves also, but like I said, all that whining I did about my shim adjustments happening too rapidly (I guess in reality, they weren't, according to the: Pitch them at the 20 hour mark recommendation) - I don't feel bad at all reading something like that - makes me realize how lucky I have really been running stock Ti valves past a certain recommended service limit, if indeed 20 hours is the point you should toss a valve. Sometimes, the stuff I don't read or hear, is a blessing :worthy:.

Edited by nokickstandsallowed
I just thought of a comparison.

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They are probably talking about the hardcore racer types that rebuild their engines after every race... Or they're trying to sell more valves!

Well, stock Ti valves are cheap when you get the kit on e-bay for $300 that includes everything.

I don't really get what your asking about the ss valves having to do with a 290 kit?

What I'm saying is everyone says the heavier valves rev slower, so if you combine that with a big bore kit that revs slower does that compound the problem or just make it less noticeable?

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where i noticed the ss valves is when i kick start the engine dosnt turn over as freely. if i was to do it again i would go back to titanium.

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What I'm saying is everyone says the heavier valves rev slower, so if you combine that with a big bore kit that revs slower does that compound the problem or just make it less noticeable?

Well, the 290 kit dosen't actually rev slower, the 83mm aftermarket pistons are actually lighter than the stock pistons :thumbsup: The issue with boring out any 4 stroke is that the meat of the power gets lower in the rpm's as the bore size goes up. Torque goes up, but the "powerband per se" is lowered. This is because of the stock port configuration is designed for 250cc. A quality port job/carb bore/cam combo and you wouldn't even know the bike has a big bore.

My bike has a 290cc motor with absolutly every mod/part/service williamsmotowerx offers, my issue was actually having to add a heavier flywheel because it was too damn snappy haha

"Nokickstandsallowed" Those 20 hour change intervals defintely don't relate to meer mortals, I have 60 hours on my dimpled valves thus far, no issues. It probably has more to do with the factory teams that use them, I think I remember seeing something where a factory mechanic talked about the normal rebuild process of the new race 4 strokes and he said friday's before the races the motors would get taken apart and picked apart with a fine tooth comb, but all that they would replace every time no matter what was the valves and piston.

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Well, the 290 kit dosen't actually rev slower, the 83mm aftermarket pistons are actually lighter than the stock pistons :ride: The issue with boring out any 4 stroke is that the meat of the power gets lower in the rpm's as the bore size goes up. Torque goes up, but the "powerband per se" is lowered. This is because of the stock port configuration is designed for 250cc. A quality port job/carb bore/cam combo and you wouldn't even know the bike has a big bore.

My bike has a 290cc motor with absolutly every mod/part/service williamsmotowerx offers, my issue was actually having to add a heavier flywheel because it was too damn snappy haha

"Nokickstandsallowed" Those 20 hour change intervals defintely don't relate to meer mortals, I have 60 hours on my dimpled valves thus far, no issues. It probably has more to do with the factory teams that use them, I think I remember seeing something where a factory mechanic talked about the normal rebuild process of the new race 4 strokes and he said friday's before the races the motors would get taken apart and picked apart with a fine tooth comb, but all that they would replace every time no matter what was the valves and piston.

Well, that's good to know about the 290 kits! I would love more bottom end. I really love the feel of the bike as it is right now, but I think a little more oomph in the bottom would be nice. I was riding it a little today in the forest and started going really slow, just barely crawling along and I let out the clutch a little too much and killed it. "This ain't the trials bike!" I said to myself!:thumbsup: I think with the 290 kit and maybe WR gears and this thing will be epic in the woods!

I think I might stick to OEM for the time being. I think the spreadsheet I had going put a full OEM valvetrain including the timing chain at about $375 whereas the SS valves and all the conversion doodads Would be closer to $520.

Can you use OEM seals and guides with the SS valves? That would save quite a bit, I think they want something stupid like $20 for a seal where OEM is like $4! Do you need to replace the guides every time or just when they are out of spec? I haven't torn into the engine yet so who knows what sort of condition it is in...

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The seals and guides should stay the same if you go SS. They get replaced when they are out of spec. That's the stuff I let Jesse handle at williamsmotowerx.

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That website was old, from 05 I think. (it's updated now)

The 20 hour thing came right from Kaw/Suz manual for the 250f. Never applied to the YZF's.

I see a lot of heads, the SS valves are very hard on seats. If you putt around they're fine. But if you are over 10K RPM... best advice is Ti. Valves are much cheaper than a head or seat replacement!

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