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View Full Version : Ok plz help. 250sx



Headsup
03-25-2011, 12:09 PM
Ok i am, trying to do sum maintnence , like adjust valves and such, My question is what the hell is compression stroke? and how do i get her there she is an 85..

also when its idle i hit throttle quickly and she bogs on me. Must slowly give er gas

thanks

Xpress
03-25-2011, 01:50 PM
The compression stroke is the stroke after the intake stroke. So watch your intake valve when you rotate the cranks. The piston should begin to go down, then the intake valve will open then close once the piston nears the bottom, the following stroke, where the piston rises back to the top is the compression, and neither of the valves should be open.

(it goes intake, compression, power, exhaust- all 4 strokes :) )

As for the carb issue, sounds like you have too big of a jet, or the jets are dirty, so clean the carb thoroughly (soak the jets overnight in cleaner) then see if that made any difference.

250Eddie
03-25-2011, 02:23 PM
^^^^ clean or fully rebuild your carb, these engines are hard to blow up so they hardly ever need anything done to the engine unless it was ran the wrong way.

Thorpe
03-25-2011, 02:31 PM
rtfm
They arent as bad as one would think... I would suggest reuilding the carb (not "cleaning" it) as it doesnt seem to work as well... The SX has a pretty much bullet proof motor, so treat it good, and it will do the same back....

250Eddie
03-25-2011, 04:02 PM
The SX has a pretty much bullet proof motor, so treat it good, and it will do the same back....
Vouch to that.

Headsup
03-29-2011, 10:05 AM
Ok wow guys, thanks for teh advice.. I think from i got the valves right from xpress..

Figures i thought it was pretty tough..

Also just wondering,

When my trike is in idle, If i hit the gas, and let it off i hear like sumthing drop? when the rev slows down? is that like a pump or sumthing fallen back in place??

Not sure if this is a major issuie//

Thorpe
03-29-2011, 10:33 AM
Cant say I have ever heard my motor make a noise like described, but I would look into your cam chain and tensioner for wear...

tri again
03-29-2011, 03:45 PM
The bog blah off idle is usually the slow jet.

They are only like the smallest small guitar string (.008)
so they plug easily.

The 'f' mark, or better yet, 'tdc' on the flywheel if you can find / see it
tells you where the valves are.
Both cam lobes pointing UP is the classic check IF you can even see them

That clunk you mention when you let off the gas?

is it just when sitting and revving or riding??

I know lots of people upload videos, but wouldn't it be nice
to be able to upload a simple *.wav audio file?

Headsup
03-30-2011, 12:50 AM
Ok sounds good, Its nighttime here so tomorrow ill warm it up and get some video.

Seems to be just when i am sitting in N is when it seems to make then noise, Like when i hit gas sumthing raises, when i let off it clunks back down. So to check valves i need both valves to be up as far as they go?

I notice when i rotate the rotor the valves go down and then back up. Is that the spot , when it comes back up