How To Do A Compression Test On A Motorcycle?

Just thinking aloud, never doing a compression test on a motorcycle or any engine, I figured I would do a little more profound research on how to do this test before touching my TBR7.

So I did a web search How to do a compression test on a motorcycle and found so many results. I now am taking that information and applying it to my TaoTao TBR7 motorcycle.

I have the engine compression test kit ( Got A Super-cheap Motorcycle Engine Compression Tester, From Amazon. ) and plan to use it soon since the TBR7’s engine crankcase vent expelling lots of gases is a concern. Do I have worn piston rings?

My New Motorcycle Engine Compression Tester Kit
My New Motorcycle Engine Compression Tester Kit

A Motorcycle Engine Compression Test Seems Simple.

At least my motorcycle testing should be more straightforward than doing an engine compression test on one of my cars. My cars have small engines, but they have four cylinders even though they are small. My TaoTao TBR7 has only one cylinder. It’s a thumper. 😀

A simple post, hoping if I go this wrong, someone will provide feedback before I commit myself.

How I Am Doing A Compression Test On My TBR7 Motorcycle.

  1.  Safety first and do the obvious steps to ensure working on a safe surface, working with hand and eye protection, and fire safety. My Motorcycle Garage Safety Rules – FAQ & Gather Must Have Tools For Motorcycle Owners.
  2. Turn off the fuel supply by closing the fuel petcock.
  3. I am turning kill-switch to ‘kill’ to prevent ignition sources(or remove ignition fuse if the bike has one).
  4. I am removing all spark plug(s). TaoTao TBR7 motorcycle only has one spark plug.
  5. Assemble the compression tester and size up the spark plug hole adapter to port size and thread by hand. I found an o-ring that seals the connections, so no torquing is required.
  6. Reset the pressure gauge by pressing the reset button to release pressure on the gauge.
  7. Wide-open throttle and crank the engine(or use kick start) till the pressure gauge needle stops increasing.
  8. Record the highest pressure result.
  9. (Optional) If I had a bike with more cylinders, I would repeat steps #6 till #8 till completed.
  10. Clean up equipment and restore motorcycle back to running condition.

What To Do With The Engine Compression Test Results?

Well, compare the compression pressure results to the motorcycle’s service manual.

What TaoTao TBR7 Motorcycle Service Manual?


Exactly, still looking for one. I understand the TaoTao TBR7’s 229cc motorcycle engine is based on the same design as the Honda CG-125/150 engine. However, is the cylinder compression specs in the Honda’s manual could be different from the increased cylinder size of the TBR7’s engine?

I don’t know, still looking. If you have any feedback on where I can get a service manual that applies to my TBR7 motorcycle, leave a comment. Please leave a comment if you know the cylinder compression specs as well.

Thank you!

Click To See My Recommended
TBR7 Upgrades

Picture of me, as a New Motorcyclist.
Just Me…Newly Licensed.

Hi I’m Tom, A New Motorcycle Rider and Blog Author.

I am a new rider(Pa Learners Permit at the end of 2020, and I received a Pa Motorcycle License in 2021 after passing a Motorcycle Safety Course).

I bought my first motorcycle, a TaoTao TBR7, at the beginning of 2021 and have been doing upgrades on that motorcycle since.

I added to my motorcycle collection by buying a Boom Vader Gen 2 in 2022, and that Grom-Clone motorcycle has been upgraded by me as well.

I continue to ride my Boom Vader Gen 2 motorcycle as well as my TaoTao TBR7 dual-sport bike.

Read more on my About Me page.

Fun Fact: I’ve only been on one group ride.

Leave a Comment