Bonneville T120 Compression Test

RickM46 · Apr 18, 2025 at 10:56 PM

Hi Guys,
I have a great running 2023 T120 Bonne; just turned 800 miles (don't get out much).
For the heck of it, thought I would take a compression test; I have a compression test gauge with adapters. The reading might be useful later as a baseline.
Figured the process would be:
Remove spark plug wires from plugs.
Remove spark plugs.
Test each cylinder by pressing starter for a few seconds.
Record reading on each cylinder.
Have not looked up what the factory reading should be.
Any suggestions on the process?

rpg51 · Apr 21, 2025 at 2:22 PM

Cold motor.

243jimb · Apr 21, 2025 at 4:49 PM

RickM46 said: ↑

Hi Guys,
I have a great running 2023 T120 Bonne; just turned 800 miles (don't get out much).
For the heck of it, thought I would take a compression test; I have a compression test gauge with adapters. The reading might be useful later as a baseline.
Figured the process would be:
Remove spark plug wires from plugs.
Remove spark plugs.
Test each cylinder by pressing starter for a few seconds.
Record reading on each cylinder.
Have not looked up what the factory reading should be.
Any suggestions on the process?
Click to expand...

Keep in mind that it uses a decompressor on one cylinder to assist in starting.

Forums

Bonneville T120 Compression Test

RickM46 Active Member

rpg51 Member

243jimb Member

(sold) Boosterplug Triumph Bonneville T120 (2016 - 2020)

My Bonneville T120 Not Getting Started

Triumph Bonneville T120 Recall

Triumph Bonneville T120 Recall

Bonneville T120 2018 - Rear Brake Light Won't Go Out

Share This Page

Useful Searches

Bonneville T120 Compression Test

RickM46 Active Member

rpg51 Member

243jimb Member

(sold) Boosterplug Triumph Bonneville T120 (2016 - 2020)

My Bonneville T120 Not Getting Started

Triumph Bonneville T120 Recall

Triumph Bonneville T120 Recall

Bonneville T120 2018 - Rear Brake Light Won't Go Out

Share This Page