Engine Compression- how many PSI or BAR it should be?

CRM250Mongolia · Post by **CRM250Mongolia** » 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

Post by **fallenmikethebike** » 30 May 2016, 08:50

Hi Ank, 10/ 11 bar should be OK. Is there compression on the kick start?
It sounds like the mixing of LED lights has upset the PGM, It's worth taking out those updates to see if the bike will then run correctly.If the engine can run properly, which it is doing at times, the fault isn't continuous.
Mike

CRM250Mongolia · Post by **CRM250Mongolia** » 30 May 2016, 09:40

Hi Mike,

Thank you very much for your reply.
Yes there is compression on the kick. i took out the sparkle and kick it, it blows.

That's one thing that never come in to my mind. Surely i will take out led reconnect the old light.
The reason i put LED is that when i turn on the Head light, factory one, engine will turn of few moments after.
I tried putting the magnet (generator), which locates on left side, with old CRM250's but it runned worse. power was down. So i'm thinking there is problem with my magnet maybe its aged or there is a some wire cut open and causing issue.

Please advice me your thought.

Thank you again.
Ank

Post by **fallenmikethebike** » 30 May 2016, 11:47

You will need a flywheel puller. Remove the flywheel and GENTLY clean the raised pick up/ pulse points, and the fixed pick up points [ the ones with wires going to them].
The 3 phase loom connections could well have corrosion/ dirt on them so a methodical clean from generator up might be needed.
Check the breather hole underneath the generator housing is clear to allow water out of the housing.
The reg/rectifier might be getting weak as well.
Mike

Post by **gregorious77** » 30 May 2016, 20:09

the only problem with the AR is that it is so complicated on the electrics side of things. sounds like to have something going to ground on the lighting circuit or the PGM is dead/dying?
When I had problems with my PGM I had to hotwire the lights as they stopped working showing that the powervalve controller or associated circuitry has something to do with the lights too.
is your powervalve opening as it should?
https://www.youtube.com/watch?v=yNKf8WfzDVw

CRM250Mongolia · Post by **CRM250Mongolia** » 31 May 2016, 02:20

Hello Mike,

Thank you for the reply.
Today i will check and clean the flywheel puller. Also i will try putting different rectifier.

After sitting two days in the garage, i tried to start up the motorcycle and it runs, but when i give 10% acceleration, temp lights keep turning on each time, and when i give 20-80% acceleration it engine dies right away.

I will let you know what happens after checking.

CRM250Mongolia · Post by **CRM250Mongolia** » 31 May 2016, 02:25

Hello Gregorious77,

Thank you for the reply.
I will check the power valve. Video that you have gave me, should i understand standard or ok valve should look like that?
I should make a video and upload it.

I still cant find about PGM.

Thank you

Speeddevice · Post by **Speeddevice** » 31 May 2016, 05:05

Try and get a voltmeter on the 12V output as well.
If you are seeing a fault (the lights coming on) as you increase the revs the regulator may not be regulating the voltage to the correct level which can damage the electronics in the PGM.

CRM250Mongolia · Post by **CRM250Mongolia** » 07 Jun 2016, 02:39

Hello all,

Turns out that rectifier is get old and could not move the RC valve. I'm going to put an order on rectifier.

Thank you for the all advises and it helped lot.

Best regards,

CRM Mongolia

Engine Compression- how many PSI or BAR it should be?

Engine Compression- how many PSI or BAR it should be?

Re: Engine Compression- how many PSI or BAR it should be?

Re: Engine Compression- how many PSI or BAR it should be?

Re: Engine Compression- how many PSI or BAR it should be?

Re: Engine Compression- how many PSI or BAR it should be?

Re: Engine Compression- how many PSI or BAR it should be?

Re: Engine Compression- how many PSI or BAR it should be?

Re: Engine Compression- how many PSI or BAR it should be?

Re: Engine Compression- how many PSI or BAR it should be?