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Is a special wrench required to remove the velocity stack from the Dellorto VHB on my bike? It has four "notches" on it around the edge - like the one in the link below.

http://guzzino.com/devestvhbss1.html

You can use a spanner of appropriate diameter on the notches. I just use a small square of rubber wrapped around the stack to prevent slipping when I unscrew it by hand. Dan

Daniil wrote:You can use a spanner of appropriate diameter on the notches. I just use a small square of rubber wrapped around the stack to prevent slipping when I unscrew it by hand. Dan

It has notches cut in not flats on it. Looks like it would take a wrench like this:



I tried unscrewing it by hand but dont think it has moved in 40 yrs.

" I tried unscrewing it by hand but dont think it has moved in 40 yrs. "

____ By hand has always worked for me, but I've always kept an old cut length of used bicycle-tire inner-tube for getting a good grip on such things.
__ Have you considered trying warming-up the carb-body and then stick a piece of ice into just the stack only, just before trying to loosen it?
(This time of year, you should be able to find an icesickle to cut-down for a near perfect fit.)


-Bob

I wrap a piece of emery cloth around the base of the velocity stack, then firmly wrap my hand around the entire diameter of the stack so that the emery cloth does not slip and mar the stack, and so as not to compress the walls of the stack while squeezing it so unevenly that I risk cracking it (if it is a plastic stack.)

The threads are fine pitched, and the oil, fuel and dirt of ages is just holding you back.

Once you get the velocity stack to budge it will unscrew the rest of the way rather easily. It may feel like there is gravel in the threads as you unscrew it, I would expect that if it has not been moved for decades. You can flush the threads with WD40 after the stack is removed and it will thread back on smoothly.

I will give the by hand methods a try. Will report back with my results.

DewCatTea-Bob wrote:" I tried unscrewing it by hand but dont think it has moved in 40 yrs. "

____ By hand has always worked for me, but I've always kept an old cut length of used bicycle-tire inner-tube for getting a good grip on such things.
__ Have you considered trying warming-up the carb-body and then stick a piece of ice into just the stack only, just before trying to loosen it?
(This time of year, you should be able to find an icesickle to cut-down for a near perfect fit.)


-Bob

have done this with fuel drained of coarse...

Was able to remove it easily. A flat blade screwdriver in the notch and a few tabs of a mallet on the screwdriver. Once the "seal" was broken, it screwed right off.

I don't have a velocity stack on my 250 bitsa but I think a strap wrench would do it. They can be purchased from Harbor Freight. They're inexpensive and sold in pairs, small and large.
Wally Anderson
ducmotorcycles@aol.com