2003 lx225 OX66 knocking sound

[tritoony]

I can hear a slight knocking sound in #6 cylinder when turning the motor over with the starter and the spark plug installed. A Remove the spark plug and the knock goes away. I have tried all of the other cylinders and it only occurs when the plug is installed in # 6 . Any thoughts about the cause of this .

 

[99yam40]

wrist pin or lower rod bearing maybe

 

[jerryjerry05]

Compression test?
Bore scope/camera?

 

[flyingscott]

Run the piston to just beyond TDC on the down stroke. Take a pencil and push on the piston, if you hear a clunk take the motor apart.

 

[tritoony]

all pistons, bearings have just been replaced, I even took the motor back apart and checked everything again. I can not find anything out of spec . I put it back together and nothing changed. I did put a borescope inside cylinder and everything looks as it should . The piston is tight, makes no movement when just beyond tdc .

 

[tritoony]

update on my 225, I swapped out another powerhead because I could not determine what was wrong with the original one. This powerhead has 100 psi on all 6 cylinders. It starts and runs fine up to 2500 rpm, then it shuts off, like turning off the key. It starts back up instantly, will run great below 2500 . I have replaced all of the filters, fuel pumps, plugs, caps . I dont think it is a fuel problem because I sprayed a gas mist while running and it died instead of picking up and going. It runs up to 5000 on the hose in my driveway. Any ideals to get the rpms up to normal ?

 

[99yam40]

sounds to me like you cannot get the RPMS up due to VST running out of fuel if the motor will get up with no load on it.
takes more fuel under a load.
does it help any when pumping the primmer bulb?
or turn the key off as soon as the motor dies and then drain the VST to see how much fuel comes out

 

[tritoony]

sounds to me like you cannot get the RPMS up due to VST running out of fuel if the motor will get up with no load on it.
takes more fuel under a load.
does it help any when pumping the primmer bulb?
or turn the key off as soon as the motor dies and then drain the VST to see how much fuel comes out

I put a fuel pressure gauge on it and while idling it reads 35 psi ,At 2400 rpm.it reads 36 psi and then dies, still has 36 psi when dead, I drained the vst and there was 12.5 ounces of fuel in it. It did not help when pumping the primer bulb, it still dies