[[email protected]]

They e-mailed me the same thing when I was trying to figure out where all my compression went !
You can sure try it though. Doug

[gprodick]

Well, I guess I'll get to the bottom of it, when I do the install. Considering your experiences, I will at least be prepared to go to plan B, if it turns out to not work at the stock setting.

Thanks, again.

[xman]

Make sure you have a shim kit handy. Unless you have a decent dealer around you.

[xman]

As promised, I checked the clearence on my decompressor this weekend. With the exhaust valve at a perfect .011, the decompressor is at .022 .
Hope this helps you.

[gprodick]

Thanks, Stuck In Vegas. That's right about the stock setting.

[xman]

Thanks, Stuck In Vegas. That's right about the stock setting.

It's close, but you still want to do the whole back it out till the starter dosen't turn thing to make sure it's right.

[[email protected]]

Yes you do, because a little bit makes a differennce.
If your bike doesn't want to start, and spins and spins a lot longer than what it did before the install, you'll know your compression is down. Doug

[[email protected]]

Did you have to change a shim SIV ? I did not. Doug

[xman]

Did you have to change a shim SIV ? I did not. Doug

Only the exhaust, and they were only off a little. I'm just a little anal that way.

[[email protected]]

Well now SIV you've got a lot of company here on that anal part ! Doug

[RottenRob]

Well now SIV you've got a lot of company here on that anal part ! Doug

Someone moderate him quick, this is getting disgusting

[[email protected]]

By the way. what's recommended is .025 in, SIV has .022 in, and when you feel the difference between those two clearances it's more signuficant than you might think.
When you look at it you'll see that .022 would have the valve tighter against the intake than .025 would, and that's the reason we were so far down on compression at startup. Doug

[Mikie1]

Actually, .025 clearance would have resulted in higher compression. At .025, The decompressor would lift the exhaust valve .003 LESS...

At .022 the valve would be lifted more, opening slightly earlier in the power stroke, and closing slightly later in the exhaust stroke; resulting in LESS compression.

Now I'm REALLY confused...

BTW-- The clearance you're measuring is the distance between the valve and its opening mechanism when the valve is closed, not the tightness of the valve against the valve seat. That is determined by the stiffness and preload of the valve spring.

[gprodick]

I suspect, and it has been my experience, that the gap for the decompressor does not have to be that exact. It will function well over a much wider range than either the exhaust or intake valve settings, which are infinitely more critical.

If the decompressor gap were way too much, the poor little starter motor would probably have a hard time turning the engine over.

On the low side, the decompressor seems to work fine. .022" is not enough to make a difference, in my opinion. While trying to remedy a starter motor problem, I ran mine well below .022" and had no problem. I've heard of others who tried .015" or below and it seemed to work.

I'm not saying it should be set low. I'm just saying I don't think it has to be that exact. It should not effect how the motor runs once started, as it should be disengaged at that point.

[xman]

I suspect, and it has been my experience, that the gap for the decompressor does not have to be that exact. It will function well over a much wider range than either the exhaust or intake valve settings, which are infinitely more critical.

If the decompressor gap were way too much, the poor little starter motor would probably have a hard time turning the engine over.

On the low side, the decompressor seems to work fine. .022" is not enough to make a difference, in my opinion. While trying to remedy a starter motor problem, I ran mine well below .022" and had no problem. I've heard of others who tried .015" or below and it seemed to work.

I'm not saying it should be set low. I'm just saying I don't think it has to be that exact. It should not effect how the motor runs once started, as it should be disengaged at that point.

Have you tried it with a Stage 1 or 2 yet? It seems to me that all this back and forth won't mean crap until you do. Otherwise, we could debate this until the end of time and still have two different opinions.
Install your Hot Cam and then we can have a conversation built on actual experience and facts, not just theory and opinions.
Oh, and have a nice day.