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I'm hoping there is an Engineer or some such out there can answer this question about the TW 200 rocker arm configuration:

When you look at the factory parts schematic you will see that the rocker arm is cast with a stub that protrudes maybe half an inch or so past the valve adjustment bolt - screw hole.

I'm thinking that this is quite a bit of mass to hang out there, particularly with a high revving engine such as the TW's. In the extreme, I'm wondering if this could potentially cause valve float, or perhaps some other kind of stress on the valve train - again, given this mass right at the end of the rocker arm.

Yamaha engineers obviously aren't stupid so there must be a reason that the rocker arm is made this way. Does it have to do with oil drip to the valve stem perhaps, or what?

Paddy
 

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Very interesting now you have me wondering myself..I almost put them on a grinder to correct the problem..
Then I thought Yamaha just might be smarter then I am... LOL
I hope you find the awnser you seek...
Mike
 

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Discussion Starter #3
Very interesting now you have me wondering myself..I almost put them on a grinder to correct the problem..
Then I thought Yamaha just might be smarter then I am... LOL
I hope you find the awnser you seek...
Mike
To give us sump'n to grab on to see how loose our tappets are? hehe..

Paddy
 

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On some ATV engines, there's a compression release on the exhaust valve cover that presses against that tab. I added one of those to a friend's high compression TW engine, so he could use his kick starter. Yamaha probably just has one rocker arm casting for these engines, so they all come out the same. That's my guess, anyway.... :unsure:
 

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Ask any question you get an awnser...
There's a deep well of knowledge here....
You gotta love this forum.,.
 
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