Describe the bug
Every 1 out of 12 times, my trains speed up instantly to anywhere from 300 to 500 km per hour.

How to reproduce
it happens by itself randomly.

Expected behavior
I expected every thing to run at there written top speed

Screenshots
If applicable, add screenshots to help explain your problem.

System Information
OS: [e.g. Windows]

System Memory: [e.g. "8gb"]

Allocated Memory: [The memory allocated to your Minecraft instance where you encountered the bug e.g. "4gb"]

CPU: [e.g. "Intel I7 7700k"]

GPU: [e.g. "MSI 1080 8gb"]

IR-Version: [e.g. "1.6.1_1.12.2"]

Forge-Version: [e.g. "1.12.2 - 14.23.5.2844"]

Modlist
Provide a list of the mods you used. You can either directly write them in here or use an online service like https://pastebin.com/ and provide the link.

latest.log
Provide the latest.log by going into your Modpack_folder/Logs, paste the contents of the file to an online service like https://pastebin.com/ and provide a link.

Additional context
Provide any additional information that might help us fix the bug.

You are on a very old version of IR, stable IR is now 1.7.3, please update.