I have run Primo on one of those headunits. I used i3 (9.6.5.245577

Baz

Edit: It was on an Ersin, but should be ok.

I see alot of advice, but which version of IGO8 or Primo is stable with the Eonon Gm5151? I am still confused about the versions . Is there any updated North America Maps for either one of these? Thanks

The answer about the software is given higher: any iGO8 should do.
Primo can be more difficult because it's more memory hungry. Nevertheless the i3 version is better suited than others. What is not mentioned higher is that some "add ons" are culprit for memory consumption - I think of TTS, 3D, DEM files, large speedcam files, .... Also setting up a route from New York to Los Angeles eats more memory than from Manhattan to Brooklyn.
Thus "user "behavior" is important too. What works for one doesn't for others.
As an advice, I would say stick to 8.3.5.

The maps are the same for iGO and Primo, no worries there. Just look in the map section : maps-buildings-dem-poi-f82/

Still failing. I'm trying the Primo 2 as the look for IGO isn't to my liking. I have loaded the maps as suggested but get the error of cant find maps.I'm wondering if the sys txt is not allowing it to follow the right path. Any suggestions? Is there a way to load it with default settings?

I can't tell what Primo you downloaded exactly, but a decent advice is to always delete the save folder until iGO or Primo works. It will be recreated so deleting it is no problem.
Read this : how-to-f128/guide-install-igo-primo-devices-with-windows-core-t3521.html
and this : maps-buildings-dem-poi-f82/where-put-map-related-files-igo-primo-t11326.html

That are the basics. You may have done it this way, then you only loose a few minutes. If not, then you learn something.

There seem to be some problems with some new maps lately. The given solution is to replace the global_cfg with the latest one. You find that file here : program-data-zip-branding-zip-license-f83/various-global-cfg-t13758-15.html#p124926.

Finally succeeded to combined Primo 2.4 which is not crashing in EONON D5152 - WinCe 6.0 thanks to:
http://www.navitotal.com/general-discussions-about-igo-core-f87/primo-crashes-when-picking-roads-avoid-t12466.html
replacing the files with : http://www.upl.me/4bHmRp
link: http://www.upl.me/ytUinU