Intake boot "softness"

[Skinner]

I use softness for lack of a better word. How about pliability? Anyhow, my intake boots (81 650GL) are original and seem soft and pliable to me. I can squeeze the sides toghether and they return to shape. They don't feel as soft as the airbox boots, but the intake boots are much thicker. So how does this compare to a brand new boot? How hard is too hard? I have nothing to compare to so don't know if my boots are good or not. I realize by the age of the boots it's probably more toward the "not" side. But like I said, I have no basis for comparison. Can anybody shed some light on this?

Thanks.
K

[tkent02]

If you can bend them they are fine. No cracks or anything?

[Skinner]

Nope. No cracks. They are not hard or rigid like I said. I'm having issues with a high idle when the bike is warm. New o-rings, completely disassembled and dipped carbs. I'm aware of the boots and o-ring issue being a common cause for a hanging idle, but the rings are new. So I'm thinking it may be the boots.

[loud et]

If you can stand on them.....yup too hard. lol
Seriously though, if they are generally flexible they should be ok.....Its obvious when they are just too hard.
We have all heard about soaking them in ATF or Wintergreen oil to restore softness or some crap like that. Eh....not too sure about that.
I will say I soaked my boots in ATF for a couple days. The soft boots or soft areas of the boots MAYBE got a bit softer but once they are hard, there is no recovery. The rock hard ones remained rock hard.

Once the carbs are installed and you are all lined up and ready to tighten the clamps down you could try a good heating with a heat gun to soften them up seconds before you tighten the clamps to help them relax and squeeze and seat against the carb throats

[loud et]

One other really stupid thing that caused me a hanging idle one time was that the #3 intake boot clamp was rotated too far inboard and the long screw on the clamp was rubbing on my throttle cam mechanism between the carbs. Caused hanging idle.
Not likely your problem but its just a quick look to make sure.

Also throttle cable hanging up. Sometimes they feel like they operate smoothly but there is a small snag inside that catches occasionally. Or its gummed up inside. Remove, flush out with cleaner/kerosene and re lube it.

[Skinner]

In my case the clamps are all set with the screws on top and not interfering with anything. I adjusted the idle with the main screw then vacuum synced the carbs. I then adjusted my pilot screws and all seemed well. But today when I rode home for lunch and then back to work the idle would not drop below 2500-3000. I'm thinking I may have to start at square one - check vacuum sync and adjust pilot screws again. Thoughts?

Oh, BTW - I checked and adjusted the valves, airbox boots are in excellent condition, and I'm using the stock airbox with a K&N filter (came with the bike). The airbox lid seals up quite nicely. New o-rings on the intake boots and carbs. Carbs were completely disassembled, dipped, new float valves installed, floats adjusted to spec, new float bowl gaskets. All passages were checked with either carb spray or compressed air. The bike pulls like a train when I'm on the throttle so those main jets are doing their job!

That about covers it!

K

[tom203]

"......Oh, BTW - I checked and adjusted the valves, airbox boots are in excellent condition, and I'm using the stock airbox with a K&N filter (came with the bike). The airbox lid seals up quite nicely. New o-rings on the intake boots and carbs. Carbs were completely disassembled, dipped, new float valves installed, floats adjusted to spec, new float bowl gaskets. All passages were checked with either carb spray or compressed air. The bike pulls like a train when I'm on the throttle so those main jets are doing their job!"

You've probably lavished too much attention on it! As to high idle stuff- you sure your "choke" is fully disengaging at carbs ?
My boots are original and are still squeezably soft, but #3 seems to be getting weak at the flange mount- I saw some 100 % silicone wrap stuff recently that claimed it was good to 500 degrees F

[Skinner]

As to high idle stuff- you sure your "choke" is fully disengaging at carbs ?

I believe so, but I will check tonight to make sure.