I have used my Kapex for about 6 months and needed to have the blade replaced/ sharpened. I went to my local woodcraft store bought a Forrest Chopmaster blade......wrong arbor size....didn't see that coming. I buy forrest blades exclusively because of the quality and the fact there US made. Is there any way to adapt to this saw??
So, was the hole in the Forrest blade larger or smaller than the one in the Kapex?
If it was smaller, as others have pointed out, you could get it re-bored to make the hole larger. See
Kapex and planer for one discussion about reboring blades, which some manufacturers do not recommend.
As an aside, in the UK you can get "blade reducing bushes", which make a hole smaller. The following bushes, taken from the
Axminster website come with a 30mm outer diameter, and with inner diameters of 1/2" to 1" in various thicknesses. They won't help in your case, but they would enable someone to, for example, fit a Kapex blade (which has a 30mm hole) to a saw with a smaller arbor.

I also have problems with the guard not returning, I keep the saw stationary on a bench, and very clean, but the guard doesn't return all the way.
Can you take a photo of the guard?
Can't seem to figure out what is sticking.
There could be several things wrong. For instance, if the saw head does not spring upwards to its fullest extent, the blade guard will not fully cover the blade. Have a look at the thread entitled
Kapex base is not level which has photos of a malfunctioning saw and the cause of the problem.
In another case, I looked at a saw which had an offcut wedged into the space between the guard and the head casing. I removing the offcut and the blade was able to return to its proper position.
I suppose I'll have to take it apart to find the problem.
Most Kapex saws are still under guarantee - can you not return the saw to get it checked and repaired free of charge?
Forrest