Kerbal Space Program

Couple of questions/comments.

The output of the engine in the first screenshot is about 12kN, under those conditions it should be making 60kN. So that's odd.

Does the engine from the first screenshot have fuel to feed it? I realize the vessel has plenty of fuel, but if the tanks feeding the engine are empty, then the only source of fuel is coming from the ISRU, which doesn't have enough output to keep the engine running at full throttle.

Without testing, I would guess that the odd numbers are mainly because some of the fuel from the ISRU is feeding the engine or engines directly, thus their final fuel flow value is going to be different than expected. That said, I'm curious if everything still adds up after taking account of the ISRU output.

Even with the curious reduced thrust of the LVN to ~12kN, the fuel flow would still be higher than the depicted value unless the ISRU is providing fuel to offset the burn.

Subject: Fuel flow bug while converting ore to fuel

Description: Fuel flow and therefore a thrust is reduced when conversion is happening. For Atomic Rocket Motor it's happening only when converting ore to liquid fuel.

Expected: Fuel flow and thrust is normal.

Result/Observed: Fuel flow and thrust is reduced.

Notes:
I did additional testing today. It's related not only to ore conversion but also to "Mk2 to 1.25m Adapter" (maybe to any empty fuel tank in the chain). On this video https://youtu.be/hHqytIg025w you can see how flow is being reduced while converting which if fine until fuel in "Mk2 to 1.25m Adapter" ends. In the end of the video I'm trying to show that bug is independent on each side.
Additionally I have attached a craft to help you reproduce the bug.

I can confirm that your observations do indeed match my own. I have updated the original description with your new additions, and have added a reproduction recipe. I also attach the simpler craft that I have used for confirmation, as well as a slightly modified version of your own craft so the test can be run statically on the pad.

The Mk2 to 1.25 adapter observation is related to it being the furthest from the engine. Once this is depleted, the engine will lose thrust while the converter is running. The other engines appear to suffer as more tanks are depleted. The simpler craft demonstrates this, and other engines can be swapped out to verify it affects all LF engines (except Jets) to some degree. The NERV is a particularly good example, and shows the effect well, as it has a fuel flow close to, and slightly above the conversion rate. This leaves more time to observe the effect.

Thank you for bringing this to our attention on the tracker. We have been aware of anecdotal reports on the forums, but a proper report has been elusive. This comprehensive report can be passed on to the Developers for attention.

This should have been fixed, please retest.