1985 85HP Force Question's

[Jaymz007]

I bought a 16' Bayliner Cobra with a 85 hp Force engine this last weekend. I had it out and was following a friend in his boat (tri-hull with 140 Johnson). We were in a no wake zone for around 2 miles, and our over heat alarms went off at the exact same time. We sat it out for 30 minutes before trying to restart. My boat started, his did not. I towed him back through the no wake zone, and my alarm never went off. Once we got through, I ran a thousand or so more RPM's through it. About a mile later, he got his boat going, so we were on our way. We dropped his boat off, and I took him skiing through a pretty weedy area. This went on for about a half an hour. When I went to pick him up, I shut the engine down. It was off for around 5 minutes. When I went to start it again, it would only start if I put it in neutral and gave it full throttle and tap the choke. When I would throttle back to engage the gear, it would die out before it would "click" into nuetral. He went and grabbed his boat and towed me to his dock. It sat for around 1.5 hours since it smelled pretty loaded up, I thought I would let it sit. When I tried to start it again, it acted the same way. I could only start it in neutral with full throttle. I let it run for about 5 minutes like that, thinking to burn out any extra fuel. (???) I dropped it into gear, it stayed running, so I took off. It was not running even close to full potential. When I got about 1/4 of a mile from the dock, it sputtered and died and the over heat alarm came on again. <br />1. At an idle, the water was just barely spitting water out of the vent holes on the back of the engine. I changed the impeller, the old one had one torn fin, and the others had flat spots worn into them.<br />2. I changed the plugs. It had Champions, I replaced with NGK's. The bottom cylinder's plug was pretty clean. The middle was fairly gummed and the top one was very gummed.<br />Since doing the work, I have not had a chance to test it. Any thoughts on what happened and did I take the correct course?<br />Also, where is the heat sensor suppose to go?<br />Thanks for your help, James

 

[12Footer]

Re: 1985 85HP Force Question's

The clean plug bothers me. compression test, and you may find the problem. Overheating to the point of hearing that buzzer has a bad effect on these engines.It tends to melt a hole in the piston,if it is operated past hearing that sound.<br />I'm concerned also, about where that one impeller vane ended-up in the engine's cooling circuit.<br />Sputtering water out of the exaust ports in the leg is normal,as this engine has no real telltail.<br />Test the temp with your hand.Touch the block in many areas,and look for hot spots. You should be able to hold a finger anywhere on the block for 3 seconds on a warmed-up engine.If you get a 3rd degree burn, (JK,bot they can get HOT ), you have circulation problems.<br />If the compression test comes up good to go, and you don't have overheating problems, give it another go. It couldn't hurt to decarbon it,if you haven't lately.

 

[Jaymz007]

Re: 1985 85HP Force Question's

Hi, <br />The impeller vein never broke all of the way off. It had a big crack about 1/4 inch from the end. <br />The engine may have run 20 seconds after the alarm sounded. Since this is my first boat, at first, I didn't even know what the heck it was (Duh!)<br />I was only going no wake speed at that time. <br />The tank had a half tank of gas in it when I picked the boat up. The guy I bought it from took me out on it to show me everything worked. So, I don't know if the gas was in question or not. I'm hoping the plugs help out though. I'm also thinking about dumping all of the gas just to get a fresh start. <br />By the way, how do you de-carbon the engine?<br />Thanks, James

 

[rogerwa]

Re: 1985 85HP Force Question's

I'm not sure I would change the plugs to NGK. The ones that are spec'd fit a certain heat range. If you are have cooling problems, I don't think you want a hotter plug.