YIKES and Oh no. Piston is squeeking?....

[tackhammerjr]

BOAT MECHANIC REQUEST PLEASE<br /><br />I put a new piston in a 3 cylinder (middle) 1995 Force 70hp motor. Like magic, it started with the first crank. All 3 cylinders testing about 110 PSI. <br /><br />I finally got everything back together including the throttle cable adjusted. I've been letting it idle and only increased the RPM a few times so the rings would break in.<br /><br />For 3 days now, I've been very proud of myself for the motor to be running so smooth since I'm not a mechanic. <br /><br />I was actually thinking of putting it in the lake tommorrow and putting around when I heard a squeek sound. I killed it immediately, took the plugs out and tried to spin the crank by hand. Sure enough, it sounds like metal on metal .<br /><br />It's too hot to look at closely and don't even know if it's the one I replaced yet. Once it cools down, I can listen and identify it. I even put the oil mix a little higher for lubrication until it breaks in.<br /><br />The guy that had the motor before had the top water jet outlet plugged by putting a screw in the end of the tube. Did I make a mistake of letting that jet out? The water is pretty hot that comes out of it. I actually don't know where it vents to. The other outlet at the bottom of the motor case is warm but not hot.<br /><br />What would cause the piston(s) to try and freeze?<br />YIKES. Please help???

 

[tackhammerjr]

Re: YIKES and Oh no. Piston is squeeking?....

Funny. I'm answering my own board messages. Posting this because you might be able to use this information too?<br /><br />Found the squeek.<br /><br />Here's a tip and a trick for anyone that is having piston problems (at least on a FORCE). You can take off the intake manifold and see the Piston rod. In fact, you can remove the rod from the crank and slide the piston right out the top of the motor if you have the head off - without dismanteling the block!!!<br /><br />Ok, so I pushed my luck cheating and used the same cage bearings where the rod attaches to the cam. It got so dry that it cooked the bearings. Literally pieces were rubbing on the cam.<br /><br />So, good news, I can put new bearings in. Bad news, why did it toast them? It looked dry like no oil getting in there like the other two cylinders. Or it could be that the oil just fried. <br /><br />I'll order and put new bearings in but any idea WHY it happened? Think the old rollers got out of order or the cage was reversed and that made the difference?

 

[emckelvy]

Re: YIKES and Oh no. Piston is squeeking?....

OK, think about what you said; dry, like no oil getting to the bearings. Since the only way a 2-stroke like this gets oil is in the gas, it stands to reason the cyl in question is getting no fuel. <br /><br />Check that carb for plugged jets, or other problems causing a no-fuel condition. Also you very likely toasted the piston, cylinder, rod surfaces, and crank journal if you ran with no oil.<br /><br />G'luck.........ed