The Fruit & Orchards forum is very active even in winter and may attract more response if your cherry questions are posted there.

Without seeing the tree or detailed photos, it is hard to tell you how to proceed :-) That could be why so little response to your question.

Sweet cherries get to be BIG trees and for that reason are almost always grafted to a dwarfing rootstock, if not both that and a second interstock. And it is my experience that grafts on cherries tend to fail more than on a lot of other grafted fruits......one tends to see not a lot of multigraft variety cherries for that reason. And they tend to have a pretty pathetic reputation when you do :-)

The small, dark-fruited cherry you describe sounds very much like an understock that has taken over. Generally with multigrafts, the varieties grafted are at least desirable and/or popular sweet cherry cultivars, not some semi-weedy, untasty, mostly pit type. If that is the case, you will be fighting a losing battle trying to contain this. How old/big is this tree? Might it make more sense to just replace it with a young, new, properly dwarf tree? There are self-fertile varieties of cherry if space is an issue and only one tree will fit. I'd choose a self-fertile type over a multigraft any day of the week.

I have mature native black cherry trees that i would like to graft. I have cut off mature apple trees at 3 feet and bark grafted them. I do inlet bark grafts on larger native pecans. Does anyone have experience bark or or inlay bark grafting on cherry trees cut off at 3 feet?

HI:
For the past two years my cherry trees(5 yr old), Bing, Stella, Montgomery and Black Tartanian blossom, set cherries but the cherries only get a little bigger than the pit.
The tree in the neighbors yard does wonderful.
Any suggestions