Engine problems from reversed oil line check valve?

[bucky4]

My 97 150 Johnson Ficht was a great engine the first year. (believe it or not!) In the spring of 98, I had the factory upgrades and 30 hour maintenance performed by a so-called "authorized" dealer. (My second mistake!) <br /><br />As part of this upgrade/maintenance, he installed a new oil line check valve, but installed it in reverse. As a result, the excess oil was not being returned to the tank, but was being pumped through the cylinders. (You can't imagine the smoke!!!) <br />The problem was rectified, but the engine has sputtered and missed at lower rpms ever since. 1800-2400 rpms is extremely bad and seems to be getting worse every year. Long no-wake areas at idle also cokes up the engine badly. <br /><br />I've followed the advice of another dealer and many on this site by decarbing often, switching to NGK plugs, indexing them, using synthetic oil, etc, etc, etc. Last year, I even cleaned the plugs after every use; however, nothing seems to help. <br /><br />Even though OMC engineers assured me that no harm was done to the engine, this lingering problem obviously tells me differently. Is there anything else I can check or have checked that may be the problem? I know the reliability of these motors is extremely poor, but it did run good at one time so I'm hoping I can get it back. <br /><br />Thanks,<br />Jim

 

[WillyBWright]

Re: Engine problems from reversed oil line check valve?

Their reliability isn't so awful. If they were going to fail, most did long ago. The upgrades they phased in made a big difference. I agree with the manufacturer in that what happened can't be causing your problem. I'd lean more toward a problem with a sensor causing the computer to meter out an overrich mixture. Certain failures allow the motor to be run, but more gas is dumped thru it as a default to make the motor runable under all conditions. I should also mention that all DFI motors soot-up the sparkplugs. If you have an oily soot, that's what fouls the plugs.

 

[bucky4]

Re: Engine problems from reversed oil line check valve?

If I may add a few more details about my problem...<br /><br />In August of 98, the #6 cylinder blew and the powerhead was replaced. (so much for OMC engineers, eh?!!!) However, the missing problem was there before the blown motor and it still shows up today, 6-1/2 years later. <br /><br />I had another dealer do the powerhead repair and after that, he had that thing in his shop and on the water 5 times over the next year trying to solve the miss. No luck - computer readings were all NORMAL and no failure codes generated!<br />This guy was a reputable dealer, so I believe he would have found the problem. He was as frustrated as I was!<br /><br />BTW, I've been told that there has been only one software upgrade for my motor and, of course, it already has it installed. (reinstalled 3 times!)