Home Forums Tech Talk Unknown hour rec engine, what to look for to know when to rebuild. Reply To: Unknown hour rec engine, what to look for to know when to rebuild.

#9130
Kirk Deason
Participant

Hi David,

A compression test would be a good start.  I cannot comment with any authority on what you should expect from a Rotax, but when I test my stock Hondas, I expect to see about 120 PSI. Get a baseline and test again after running for a couple days. If the pressure is dropping below your baseline then the ring may be due for replacement and it is probably ready for a new top-end.

You may also want to post in the Rotax specific forum further down the page.