Engine Compression- how many PSI or BAR it should be?
Posted: 30 May 2016, 08:11
Hello all,
My English is not good and i tried my best. Apologies if there is mistakes. I hope you understand.
This is my first off road motorcycle and i'm very happy that i bought Honda. I'm learning new things on each step.
I bought a CRM250 couple months ago. On the paper it says manufactured in 2001, but i think it is some where between 91-96 MK2. On the frame there is a color badge says it is CRM250AR. Condition and way she is stored is very good, no rust at all. Everything is fully operational except front light. I changed to LED.
Recently i having a difficulty to find what happened with the power. At the beginning power was so good, but the day i put LED light bar, Temp light turned on when i started it and then there was no acceleration for few seconds. Also rear light was gone. I guessing there could be electric problem. I will check each wires on weekends. i'm hoping no series thing happened. Mechanics here in my country couldn't find the problem.
Since that day, power get very bad, very slow on the acceleration but when i give full acceleration sudden, it runs like before(on 1st -3rd gear). but when gear goes up to 4th an 5th, there is power.
Here are what i have done so far:
-I checked if exhaust chamber and silencer blocked, they ok
-I changed air filter
-I changed sparkle to Iridium
- cleaned the carburetor
- There was a crack on the air reed, but i put new one (really hoping this was causing problem but it is not)
- checked and put transmission oil
- Checked oil pump, it is working, but i'm not sure about ratio.
- Drained out all the coolant and put knew one
my plan is to check pressure of the compression of the engine, but i don't know what psi or bar it should be.
So, please advice me what to check next.
Best regards,
Ank
My English is not good and i tried my best. Apologies if there is mistakes. I hope you understand.

This is my first off road motorcycle and i'm very happy that i bought Honda. I'm learning new things on each step.
I bought a CRM250 couple months ago. On the paper it says manufactured in 2001, but i think it is some where between 91-96 MK2. On the frame there is a color badge says it is CRM250AR. Condition and way she is stored is very good, no rust at all. Everything is fully operational except front light. I changed to LED.
Recently i having a difficulty to find what happened with the power. At the beginning power was so good, but the day i put LED light bar, Temp light turned on when i started it and then there was no acceleration for few seconds. Also rear light was gone. I guessing there could be electric problem. I will check each wires on weekends. i'm hoping no series thing happened. Mechanics here in my country couldn't find the problem.
Since that day, power get very bad, very slow on the acceleration but when i give full acceleration sudden, it runs like before(on 1st -3rd gear). but when gear goes up to 4th an 5th, there is power.
Here are what i have done so far:
-I checked if exhaust chamber and silencer blocked, they ok
-I changed air filter
-I changed sparkle to Iridium
- cleaned the carburetor
- There was a crack on the air reed, but i put new one (really hoping this was causing problem but it is not)
- checked and put transmission oil
- Checked oil pump, it is working, but i'm not sure about ratio.
- Drained out all the coolant and put knew one
my plan is to check pressure of the compression of the engine, but i don't know what psi or bar it should be.
So, please advice me what to check next.
Best regards,
Ank