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fix for ripped rubber boot on thottle cable at carb
Posted: 07:54 pm Jan 18 2007
by krazyinski
3/4 heat shrink tube works great for a quick repair on the boot of the throttle cable at the top of the carb.
Throttle Cable boot
Posted: 12:27 pm Sep 29 2008
by barryadam
Using Search, I was not able to find any indication this was a common problem, but I discovered that indeed my throttle cable boot was broken open. Thanks for the tip krazyinski. That'll hold me until the new one comes in.
I'm assuming that this air leak through the broken boot into the top of the carb is what has been causing the lean, hot running on my 2001 220. I don't remember from my last carb teardown if there is any other seals for this cable in the top cap, or if the integrity of the boot is critical. Maybe someone has more recent expereince and can comment.
Thanks.
Posted: 01:23 pm Sep 29 2008
by fuzzy
The slide is the seal...
Posted: 03:51 pm Sep 29 2008
by canyncarvr
fuzzy wrote:The slide is the seal...
What he said....
The boot on the throttle cable is not meant to be an air 'seal'.
A problem with the boot can lead to dirt/water/crud getting into the top of the carb....which will 'wear out' the slide..which will lead to a lean condition (air leak).
Posted: 10:03 am Sep 30 2008
by barryadam
I've seen a few different models of carbs and the slide fitment in the body is by no means airtight. The entire upper chamber of the carb housing where the spring is should see the same vacuum as the rest of the body. It is sealed by the boot and the upper cap gasket. Otherwise, it would act as a diaphragm style carb and the vacuum would suck the slide closed.
Don't flame me, I'm just theorizing here. Come to think of it, the cable housing itself would be a conduit to leak incoming air if what I said above was true.
Well, I guess I need to fix the broken boot anyways.
To quote Dr. Bob, "...never say "fixed" to a dog!"
Posted: 01:18 pm Sep 30 2008
by KarlP
I think you are correct in that the area above the slide gets to the same pressure as the throat of the carb, given a constant throttle position. I can't see why not.
I usually find some grit in the slide at the base of the spring and around the little plasic thingy.
I doubt a busted boot would effect running, though. Clearence changes between slide and carb body might but that would be over a long period of time