OMC King Cobra - Ca-thunk on starting attempts

[dougbreault]

I've got an OMC 262 King Cobra I/O on an 89 Four Winns Horizon. The boat hasn't been started in about 2 years.<br /><br />The electrical system (stereo, lights etc) I got running after a litte work and luck. <br /><br />The battery is fully charged. <br /><br />Turning the key used to make a single "click" noise. I whacked the side of the starter with a hammer and now when I turn the key, it goes "CA-THUNK!" once and does nothing else.<br /><br />I pulled all the plugs and fogged each cylinder for 2 seconds. Replaced all the plugs with new ones gapped to .035 as the manual specs required. <br /><br />Cleaned the positive battery terminal connection at the solenoid (if that's the little barrel-like thing on top of the starter with terminal connections on it). <br /><br />I've not cleaned the negative battery terminal yet, it's somewhere in the back of the engine I think, the wire goes back there anyway. Will have to remove a panel to get at it. Also haven't cleaned the negative terminal on the selenoid, it is a little 3/8 nut on a small post with a small black wire going to it. It looks pretty rusty.<br /><br />I sprayed a tiny bit of carb cleaner in the carb. <br /><br />Before the new plugs went in, I was able to manually crank the engine with a wrench and it was hard at first but now turns OK. <br /><br />Any ideas what the "ca-thunk" might be? It doesn't make the normal motor starting noises, just goes "ca-THUNK!". I believe the voltage across the terminals on the little barrel thing (solenoid) was about 5.6V. <br /><br />Thanks for any and all advice. This board is fantastic. <br /><br />Doug<br />dougbreault@yahoo.com

 

[tommays]

Re: OMC King Cobra - Ca-thunk on starting attempts

http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012808 <br /><br /><br />this is a guide to most starter systems but it sounds like your not getting full power to the starter<br /><br />the first step is really if the batterys are good after sitting 2 years<br /><br />a load test at a battery place would rule this out and let you work from there<br /><br />the batterys should hold about 12.8 volts when fully charged<br /><br /><br />tommays

 

[dougbreault]

Re: OMC King Cobra - Ca-thunk on starting attempts

I've tried two batteries, both have been fully charged on a charger, and both light up all the lights on a battery tester. (The first battery is the one that came with the boat, it could be a little old. The second one is a year old battery I use for my electric trolling motor for my jon boat.)<br /><br />Can a condition exist where the voltage reads properly yet the battery does not have enough juice to start the motor?<br /><br />Thanks a lot for the help,<br />Doug<br /><br />PS. The OMC 262 King Cobra is a 4.3L, forgot to mention that in the original post. Also, striper season is in high gear right now here in Massachusetts, so sorry for not reading all the manuals first. Was hoping to catch a few good weeks of fishing. And, this is my first powered boat, as you can probably tell.

 

[olbuddyjack]

Re: OMC King Cobra - Ca-thunk on starting attempts

Originally posted by DougBreault:<br /> <br />Can a condition exist where the voltage reads properly yet the battery does not have enough juice to start the motor?<br /><br />

Yep. An easy way to confirm this is to borrow the battery from your truck and try it in the boat. If you still got a problem its not the battery.<br /><br />You can bypass the hidden ground connection with a jumper cable clipped to the block and the neg. battery post.<br /><br />If your sure the wirings good pull the starter and see if it works off of the engine. The "clunk" sounds like the starter drive is engaging but not turning the engine(brushes could be corroded).<br /><br />Something thats bothering me, when you cranked the engine manually it was "hard at first."<br /><br />If there is significat rust in the cylinders the engine may be too tight for the starter to spin. You may have to pull the plugs again and work a little more at freeing it up.<br /><br />Good luck!

 

[dougbreault]

Re: OMC King Cobra - Ca-thunk on starting attempts

Thanks. I fogged the cylinders for about 1.5 seconds each. To free up the engine more, what is best? Should I re-fog and recrank the engine? Or is there something else I should lube or spray?

 

[Lou C]

Re: OMC King Cobra - Ca-thunk on starting attempts

I have heard that people have freed up engines that have not run in a while by putting some Marvel Myster Oil in the cylinders. So you could get one of those oil squirt cans, fill with the oil, remove the plugs, squirt some oil in each cylinder, let it sit for a couple of days, then try to crank it with the plugs out to eliminate the resistance of compression. If you can crank it over by hand with a wrench on the crankshaft pulley but it won't crank with the starter, you need to go back and trouble shoot the starter system. If the motor was fogged properly when last winterized is should not be locked up, but I guess anything can happen.

 

[olbuddyjack]

Re: OMC King Cobra - Ca-thunk on starting attempts

I've heard of using tranny fluid and penetrating oil(PB Blaster)also but I like Lou's idea better.<br />Make sure the starting systems ok then put the starter back on and try it with the plugs out. Don't crank it more than a minute or two without letting the starter cool or you'll wreck the armature. Oh, and don't forget to ground the coil too.

 

[mkast]

Re: OMC King Cobra - Ca-thunk on starting attempts

If you can turn the engine over by hand, any working starter with a charged battery will turn the engine over, starter has a little more torque than your wrist. Remove the starter, insp for corrosion esp. in the drive area. Bench test starter, good battery and jumper cables. Parts houses like Auto Zone will test the starter for free. After you verify the starter is operational and you can turn the engine over by hand, reinstall the starter. Remove the spark plugs, crank the engine over acouple of times to evacuate the cylinders, before you reinstall the plugs. Any corrosion in the cylinders won't get better with more lube, just more lube in the cylinders, you already have the engine turned by hand. Prime the carb, turn on the water, and cross your fingers.