2003 STX 12F engine knocks in left turn - PWC Forum: The best hang-out for Personal WaterCraft enthusiasts

g3326m · 06-04-2009, 09:52 PM

I recently got a 2003 STX 12F with 67 hours on it. it is a 4 stroke fuel injected. runs strong. I chnaged the oil and filter after a brief maden voyage. I didn't notice any issues other than slugish power from the old gas. I changed the oil and filter and now I have a knocking noise when I make a hard left the gets loader the more rpms it turns while in the turn. Quiets down as soon as I straten it up. Does not do this during right hand turns. Doubled checked oil level. looks good. Thought it may be that the shop gave me the wrong oil filter. I asked the shop and they are puzzled. Any ideas on this one?

Thanks, G

**JayDawg** · 06-05-2009, 12:56 AM

Since it only does it on left hand turns, turn the ski to the left when running and see if anything is binding up or is causing problems such as the jet nozzle. If you are 100% sure it is the motor and not something else, does it do it when the ski is turned to the left or when you are leaning and turning to the left?

g3326m · 06-05-2009, 06:56 AM

To be honest, I haven't thought of leaning the ski at speed while going straight to see. I have only noticed it while leaning to the left while making a hard left turn with the rpm's up. I can say that the noise is loader, the higher the rpm's. I plan to change the oil filter and top off the oil this weekend and take it out if it will ever quit raining here in GA. Thanks for your reply, food for thought, I will determin if it is the turn or the lean that causes the knock. Any ideas as what the cause could be in either situation?
G

**JayDawg** · 06-06-2009, 02:03 AM

Without looking at it and being there, I have to be honest that I have no clue?

AKnight007 · 08-07-2010, 01:20 PM

Hi, I have the same 2003 Kawasaki STX 12f with the same problem. I have good news for you. The problem is not the engine or an engine knocking noise. The knocking noise you are hearing is coming from the the water jet out the back hitting the reversing gate on the left hand turn. Mine did the same thing and I thought is was the engine also. See if you have some play in the gate with it locked up in the forward position. It may just seen lose but is enough for water to be hitting it. To check this use something to hold the gate tight in the locked forward postion like a large thick rubberband, string or wire just for a test. Run the ski in a hard left turn and you will suprised that the knocking is gone. Or you can hold down the handle tightly for the forward/rever level while making the same turn. The noise you are hearing is coming from that handle knocking caused by the gate moving back and forth fast. If you can screw in the end nut of the cable on either end at the gate or handle lever you may can take up the slack. I didn't have any more trhead to take up on mine. So, I took several large thick rubber bands, attached them to the level in the the cable. Ran them over to the left side to hold tension on the cable which pulls and holds the gate tight. You have to becareful so that in the nutral position with the engine at idle the handle lever might walk to the foward position. I garauntee the water hitting the gate and making the level handle knock is your problem.