seized Johnson 200hp

[Scubaonline]

Desperately in need of help and advice. I bought and had a 200Hp johnson fitted to my RIB and after 30 hours use it has seized solid.<br />The dealer claims that water in the fuel was the problem, I am not so sure. All the fuel used was fresh with the exception of a small residual in the tank that was there when we bought the boat.<br />The engine had been running fine and then 20 mins after starting on the day it seized the engine made a strange sound - not easy to identitify the sound but certainly not back firing etc and then seized solid.<br />The dealer at the moment it attempting to free it up by squirting lubricant through the spark plug holes and turn the flywheel with a bar.<br />I feel that something more catastrophic has happended and really would appreciate any advice.

 

[ledgefinder]

Re: seized Johnson 200hp

It has almost certainly scored one or more cylinders, and needs to be rebuilt. Try a compression test if in doubt.<br /><br />Could have run lean on one cylinder (due to dirty carbs and/or fuel), overheated, or ?. Tough to tell from data given. Was it getting enough oil?

 

[Scubaonline]

Re: seized Johnson 200hp

Thanks for your reply.<br />The oil tank was full and no alarms sounded at all from it.<br />One thing that does concern me now is that the dealer installed the oil tank on the floor of the RIB and it would have been subjected to water immersion. Could oil have gotten into the oil tank and thence into the engine that way depriving it of water ?<br />Also when the engine was intalled the dealer wired it up so that a bunch of wires - 6 in total - were left on the floor with their connector block. <br />This did get wet and oily and as a quick fix I had to cut the wires and rewire through crimped connectors and route well above the waterline.<br />Could a fault here have caused a lack of oil do you think ? <br />Although I would have thought the oul alarm would have sounded if this was the case.

 

[NEECAPRS]

Re: seized Johnson 200hp

Other Possibilities: If the crank/flywheel can be turned very slightly-rocking back and forth- the problem may be in the bottom end with a seized drive shaft bearing. ORRRR,it could be the all-too-common dropped top main bearing( and seizure). I'm assuming this is a 90 degree, 6 cylinder. Sorry to hear these symptoms.

 

[seahorse5]

Re: seized Johnson 200hp

Use a turkey baster and "suck up" a sample from the bottom of the tank and squirt it into a glass jar. You will see if there is any sludge or water in the tank, which could have caused your problem.

 

[Scubaonline]

Re: seized Johnson 200hp

thanks guys<br /><br />sucked out some fuel - hardly any water at all in tank but the colour of the fuel in the fuel filter a totally different colour ! Tank is greenish and filter is clearish with a bit of rust.<br />The flywheel is locked solid.<br />Mech tried to free with oil thru ports and bar on flywheel to no avail.<br />Wants to now take off head and examine as 1 piston not taking up any oil at all.<br />What should I look for to see if it is anything other than water in the fuel causing the problem ?<br />On the outside the engine looks as good as new no paint blistering or signs of leaking gaskets.

 

[Neil]

Re: seized Johnson 200hp

Water in the fuel wouldn't cause the engine to sieze whilst it was running. The problem with water in the fuel is that the engine will cough and splutter. The problem will only manifest itself when the engine is stopped. Water will quickly attack the bearings and journals.<br /><br />We had a 75HP Yamaha on our dive boat that somehow has about a pint of water in the portable fuel tank. The engine would start , cough and die. We would restart it, again it would run, splutter. Someone decided to leave it alone and use another boat. When we came to check the engine 5 days later it was solid. A strip revealed lots of rust.<br /><br />To check for water we used a paste but I can't recall its name. I can get the name if you require. Simply spread some red paste on a stick, pass this into suspected fuel and if water is present it changes colour like litmus paper. Works will very small quantities of water too.<br /><br />NG

 

[NEECAPRS]

Re: seized Johnson 200hp

Scubaonline: $ounding expensive no matter how it turns out. Ngriff1 has good advice--water in gas probably won't cause a running seizure. Remember, it won't even run with a blended mixture of 20% water in gas!(if you could make that mixture!) It seems like the best you can do now is minimize the cost of the rebuild by watching this dealer very closely. I think you may find that after loosening all the rod caps, the crank/flywheel still won't budge.If so,you might find the pistons and cylinders in good shape,but, the top main bearing seized to the crankshaft. This would not have been caused by your bad gas. It was caused by bad gas in the OMC supplier quality department. With other possibilities, you really need to have a knowledgeable rep watching the teardown.

 

[93bronco]

Re: seized Johnson 200hp

drain each one of the carb bowels to see what was in each one.<br />just a thought.