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Second Set Of Spent Intake valves

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Yep, 01 wr250f; clearance gone on last shim size (1.2mm). Next will be the third set of three intake valves.

NOTE: Trying to finger out witch would be cheaper maint. costs over 4 years- Two or four strokin.....

Note: Aprox. 8 hours between adjustments. Twisted hard. 1/3 Cut lines, 1/3 single track, 1/3 bush whacking.

Moderators please help. I'm Sick of adjusting. Shims coming out of my ying yang!

I'm contemplating anything other then titanium.

Please coment. :cry:

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Get some SS KibbleWhite valves for the bike. Should end your Ti valve problems. Be sure to get the springs also.

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I'm on my second set of intake valves, but I seem to be having better luck. I just checked the valves the other day after putting (I'm guessing) 15-20 hours on them. They are still perfectly in spec. BTW they are the OEM Titaniums. And those 15-20 hours were all at high revs, so I can't really explain why my first set went so quickly but these aren't.

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no idea why you are having such a problem.

did you replace the springs when you replaced the valves?

re-cut the seats?

air filter brand and oil used?

and most importanly, how often do you reach the rev limiter?

yes, the Kibblewhite stainless steel kit is/has been available for a while now. you can order it and the spring kit (needed!!!) from the TT store.

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i dunno, but i just rode an 05yz250 and those are BAAAAD bikes.

Yes they are!!!

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Springs, yes. Also timing chain & guides (stem seals). And I inquired about lapping valves & cutting the seats (wile this work was done on warranty by cert. mechanic. Thanks AIG) and as told there was no need to re-cut. Just install..?? They did last as long as originals; now we know. I do ride up top in revs often as intended when purchased, just like they said I could(hence the Gold warrenty plan).Funny you question'd air filter oil . No-Toil since 2nd ride. I've questiond this aswell. Alcohol ?? Nah.. I choose running Castrol 20w50 and changing it often too running expensive synthetic and changing it often?? Maybe your advice on synthetic should have been had... Dooh! I'll add that the first season I ran a barrel worth of 100 low lead aviation fuel; just cause it was free and "they" said I could... I guess that wasen't it either.. Now thinking heat/titanium is the problem. Sure liked the email on RPM's Cool Blue. That induces $bad$ vibes. Now I'll end up with the same problem I had with my '94 WR ; too fast too ride. And thanks for the add-vice. I'll contemplate RPM's tallent & a couple of electric fans to smash with my rads ($second set$).......Yes and synthetic oil. :cry:

Nice Work here guys.

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if you are going to run in the upper rpm's and see the rev limiter a lot, you WILL have to replace the valves more frequently than most people. face it, at 13,000 rpm the valves are opening and closeing 108 times per second. the faster you spin it, the more frequent parts are gonna wear out. period. no way around it.

be glad you are on a blue bike, because if you were on another color bike, you'd be on valve replacement 13 and not 3. :cry:

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face it, at 13,000 rpm the valves are opening and closeing 108 times per second.

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My calc says 216.

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sorry to butt in but ,i have an 03yzf and i only ride motorcross. Are you saying im doomed because i always rev it hard,not on the limiter but i try and keep it in the power band at all times.

i had to replace my intakes about 6mths ago and i suspect the only need ajustment now(getting harder to start).

what is the estimated survival time on valves? :cry: oh i try change my oil every 4-5 rides with silcolene semi synthetic

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Change your oil more often, clean your filter every ride and run filter skins and remove them religiously mid to late ride.

I ride mine hard near the limiter , I run two filter skins, so I get three clean filters on a 200km ride. I change my oil every 150-200km and every race day. I know have over 4000kms and shims dont need doing yet. Oil and filters are cheap. Ive used almost 28 litres of penrite oil and 6 filters at a cost of around $320, this is way cheaper than having done a set of valves + other engine wear. Even changing oil at this rate the oil is stuffed when I take it out.

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what is the estimated survival time on valves?

About a month on hondas.

The valves will tulip over time and will eventually break if not replaced. It's a trade off from using titanium. It has nothing to do with keeping the air clean or changing the oil often, although both should be done as a religion.

If you have to reduce the shim size more than 10% smaller than it was when the valve was first put in. Replace the valve.

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Another thing that does in the intake valves is chopping the throttle at high rpm's. If you chop the throttle at high rpm's, the engines compression "slams" the intake valve back into it's seat causing more damage over time than if it was allowed to somewhat gently arrive back on it's seat with a partially open throttle relieving some of this pressure. Of course, gently being a relative term at 13,500 rpm's!!! Maniac :cry:

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face it, at 13,000 rpm the valves are opening and closeing 108 times per second.

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My calc says 216.

hakka,

it's a 4 stroke. the intake valves open every other revolution. same for the exhaust valves, just happens on the next revolution. so the original number of 108 is correct if you consider a single valve.

jim aka the wrooster

'01 wr250f

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I guess I have a Monday bike... My 03 has over 120 hours, original valves still dead in the middle of spec. I ride 95% MX, 5% trails.

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I guess I have a Monday bike... My 03 has over 120 hours, original valves still dead in the middle of spec. I ride 95% MX, 5% trails.

This is one of the reasons Yamaha is my bike. I like many properties other makes have, but not having even to think about valves is so relaxing. :cry:

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My 01 wr250f is still a good dual sport with about 150 hours on it. The valve shims are down about 18% though. Will probably rebuild before long.

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It has nothing to do with keeping the air clean or changing the oil often, although both should be done as a religion.

I agree the oil wont improve valve life, but it will improve life of all other engine components including the shims. Its the air filter that is critical to valve life. Open your manual page 3-35 where it says " Proper air filter maintenance is the biggest key to preventing premature engine wear and damage" .

The intake valves wear quicker, because the dust particles are more abrasive when entering the engine compared to when theyve been pulverised by the combustion chamber and spread out leaving through three exhaust valves.

You be the judge but given yamahas track record with valve wear, I think they may be correct in there manual. Your air filter will be critical to valve wear and shim replacments.

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