Spark plug gap - Onan 5000

[Fredk20716]

I've replaced the sparkplugs, filters, etc on my genny. It is hard to start and diesels somewhat when shut down. When I spoke with Onan they stated the plugs come pre gapped at .035 however I've read somewhere that the proper gap is .025. Well which is it?

Onan 5500 Marquis Gold

[LJowdy]

Correct gap is .025

You can go here: https://www.cummins.com/generators/motorhome-and-rv and look up your generator

[tmw188]

.025 on mine too, but to get them there they seem close.