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MrDefine "slight resistance" --- a shimming we will go!

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I always here that when checkin valves make sure the feeler guage goes in with "slight resistance" when finding measurement. What the heck does that mean? If I have to push a little Anyway, just checked my valves at 50 hrs. Last check all in spec for the most part. Now Im looking at:

INTAKE

Left: .004

Right: <.0015 (that was the lowest feeler I had and it would go)

EXHAUST:

Left and right: .080-.085 (depending on definition of slight resistance)

Im shiming all but the left intake right?

Thanks gang!

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well a .006 will bend with slight resistance. I pull the cam sprocket off and tie it to the frame with the chain. Now the cam turns about 20 degrees pretty freely. Now wjile pushing the gauge between the cam and bucket i wiggle the cam back and forth to help ease it in. You will still get accurate readings and if you cna get it in then you are set. There is no way a skinny ass feeler gauge will force its way under the cam and push the valve down and give you a false reading. You dont have to worry about the cam being 100% lined up when doing this because when it is lined up it will have the biggest opening.

I hope i explained this good enough.

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btw, your valves are leaking with that sort of reading, shim them and start saving your money for a rhc valve job

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btw, your valves are leaking with that sort of reading, shim them and start saving your money for a rhc valve job
:thumbsup:

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btw, your valves are leaking with that sort of reading, shim them and start saving your money for a rhc valve job

Whats that going to cost? :thumbsup:

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The options seem nearly endless Todd. I spent hours combing through past posts and even threw a few of my own inquires out there to get edumucated. Talk to 10 different people you'll get that many different opinions. I don't think anyone would argue RHC's coated Ferria (sp?) valves are one of the best routes to go. Personally, I went the el-cheapo route and bought OEM's from Motosport and had MXTIME cut the seats and install. It's was a bit over a couple hundred bucks not counting gaskets and such. Hard telling how many hours it will last- but the bike flat out rips. But if you have the dough, get an 07 head from Ron with his valves and springs. I've learned through observation to call him on the phone. Primative method of communication, but I hear it works :thumbsup:

Keep us posted on the route you go. BTW, you can shim that the first go-around. For several bucks you'll get about 10 additional hours of riding. The stock shim is usually a .188 and I replaced it the first time with a Hotcam .160 to get it in spec.

The second shimming I had to go clear down to a hotcam .135 shim. It lasted 5 hours.

Good luck brother.

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The second shimming I had to go clear down to a hotcam .135 shim. It lasted 5 hours.

Good luck brother.

www.ronhamp.com He will take care of you. This is very true about the second shimming. It goes quick. I shimmed mine the second time and road for a few hours at hollister and took the bike up to sand mountain and it wouldnt run. There was no way in hell that i was going to open up the top end in the sand dunes so it basically caught me off gaurd.

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The best way to know if you have the right size shim is as follows:

If you are going for .006" for example, a .006" Gage will fit and a .007" will not. Always consider the size to be the one just below the one that won't fit. Now you can't force them in, when done right the right one will fit nicely and the next one just won't go in, it's that simple. Most shims come in .002" increments so you may not always be able to get to the exact size you want so go to the tighter side. I know that is different than most people think but is the right way to go, the bigger the gap the more closing velocity and the more stress to the valves. The idea in theory is to gently lay the valve on the seat not drop it from far away. Now I know we are only talking about thousandths of inches hear but you would be amazed to see how a little bit can effect the pressure put on the the valve at high rpms. Now at 13000 rpms all bets are off, and most valves are just bouncing around out of control, that's why it's so important to keep everything as close to like new spec as possible. :thumbsup:

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well a .006 will bend with slight resistance. I pull the cam sprocket off and tie it to the frame with the chain. Now the cam turns about 20 degrees pretty freely. Now wjile pushing the gauge between the cam and bucket i wiggle the cam back and forth to help ease it in. You will still get accurate readings and if you cna get it in then you are set. There is no way a skinny ass feeler gauge will force its way under the cam and push the valve down and give you a false reading. You dont have to worry about the cam being 100% lined up when doing this because when it is lined up it will have the biggest opening.

I hope i explained this good enough.

That would be great, but the 250 has a pressed on cam gear. Remember these motors are similar but not the same.

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www.ronhamp.com He will take care of you. This is very true about the second shimming. It goes quick. I shimmed mine the second time and road for a few hours at hollister and took the bike up to sand mountain and it wouldnt run. There was no way in hell that i was going to open up the top end in the sand dunes so it basically caught me off gaurd.

IS Ron used to buy the new valves and springs?

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