Looks like a quality product. I didnt have a chance to run fuel through it before Spruce asked for a review. NOTE: the square protrusion may require alteration for replacement of older primer. I had to make room for this on on my Corben BabyAce.

Tango L Verified Purchase

ACS Engine Primer 10920

Was compelled to buy this product due to having an earlier design of same which failed in service due to known fault. Hope this one proves more reliable.

John T Verified Purchase

ACS Engine Primer 10920

Worked out perfectly. Identical swap out for the primer that was in my J3.

Nice quality primer with a positive lock. Installed this unit on my experimental Super Cub using the standard 1/8 fittings off the old primer. Works perfect and I really like the locking design.

It works and the OEM Essex (aka Kohler) K2403 is no longer available new. The CRITICAL thing everyone needs to do is read the Technical Drawing pdf that is listed in blue on the Aircraft Spruce product page. The operation of this locking mechanism is very different from the OEM ESSEX primers push it in and twist a little. Failure to follow the ASY locking directions will cause a siphoning of fuel from the primer lines into the carburetor while flying that will cause the engine to run rich and foul the spark plugs. The original ASY technical drawing did not have these directions! Only four stars for not highlighting this critical difference better.

Looks like good quality, but could not use because line fittings are 5/15-24 course thread. All normal primer line fittings (AN805-2) are 5/16-32 fine thread. I will be talking to ACS about a path forward.

Lasted a bit over a year in an experimental cub. Never filled properly, and in 40 years of flying Ive used plenty of primers that didnt fill on the first stroke. But this thing upon installation would fill zero on first stroke, then half full on second stroke, and a full shot on third stroke. But then it degraded further, and about a year after initial installation (and 60 hours) it no longer works at all. Disappointed. I guess all I can do is buy new O-rings and install but will they last? Will work with ACS to see if they have solutions.

It is not expensive and looks good but my primer is leaking. I have to plug the priming line to eliminate rough running.

Good: It does have a positive lock, which was nice. Bad: Short stroke so doesnt move much fuel. Aluminum, so it wants to bind and gaul. Worked adequately for a couple of years, now wont draw in any fuel. Ill be removing it to re-install the old Lukenheimer primer I had replaced with this one. Disappointed for the cost.