CRM power loss

[crmgreece]

Hello. I recently bought a HONDA CRM MK3 from a friend in excellent condition. the bike was used for city commuting. he send the bike to change the spark plug and clean the carburetor and he send it to me. i never ride such a bike and i thought that the performance was ok, Until a friend of mine that owns a CRM MK2 ride it and told me that there is a problem with the bike. The performance was bad 130 top speed and poor acceleration. and that was true when i ride his bike! mine wont wheelie even with first gear! we checked the power valve and it is working perfect... something holds the bike and from mid range to top it does not have hard acceleration and when i turn it off after a 5 min ride it makes a fuel stain under it.air filter seems clean. i try it without an air filter and does the same.. i saw with a stroboscope the advance and when we rev the engine the light goes to right. Is that right? my friend told me that he thinks the light must move to the left...

[crmgreece]

And something else that i noticed. I have removed the tail light and indicators because i use the bike only for enduro. the frond turn light are on without blinking. they are always on! is that a problem or because i removed the back turn light worn s me?

[jim157]

The mk3 and ar front indicators are always constantly lit.

[crmgreece]

I didn t knew that. Any idea for the power loss?

[fallenmikethebike]

Start with the basics, what condition is the plug in ? What colour is it ?, Is the exhaust clear and not dribbling out oil?
Check the needle position, it would more than likely take a position raising of the clip, [ this lowers the needle and weakens the mixture allowing better combustion] IF it's not to low already!!!.
The float height might also need resetting, and /or replace the fuel inlet valve if it's letting by.
This may not cure the problem, but it's fairly cheap things to eliminate as the possible cause.
Good luck.
Mike

[gregorious77]

all of the above and I would also do a compression test.
Dribbling fuel could mean the float valve is stuck and it may be flooding the carb and running rich..
another thing to consider could be reeds.

[fallenmikethebike]

Sorry, I just re-read your original post, if the carb has been cleaned by a mechanic unfamiliar with the bike there's a good chance he has reassembled the carb incorrectly, which might also explain the fuel leak !!
Check the carb for correct assembly of all moving parts, seals/ O-rings.
Check also the carb is fitting in the rubber inlet correctly, otherwise there will be serious amounts of unfitered air getting into the engine. and weakening the mixture.
Mike

[crmgreece]

is there any guide how to assemble the carburetor?

[fallenmikethebike]

Photo of carb.


Mike

[crmgreece]

you are the best mike! thank you

[crmgreece]

what is the position of the needle?

[fallenmikethebike]

The middle position is generally standard. Move it one notch at a time, richer [ clip up ] or leaner [ clip down ].
The colour of the plug, and the engines responsiveness will dictate which way to go.
You may also need a main jet, jetting change,one way or the other, which will mean returning the needle jet back to the middle position again .
Mike

[crmgreece]

i hope that the problem is that. do you have any idea when you measure with the stroboscope and you raise the rpm the light must go to the left?

[fallenmikethebike]

I've never checked!! But if it's wrong you're b@ggered as the ignition timing is fixed.
Mike

[crmgreece]

I have the carburetor in my hands and with the first chance i will clean it to be sure that the problem is not from that. I will change the pilot jet. What is the number of the jet that i will buy?