Johnson 150 problem

[walleye710]

Looking for a second opinion on a couple issues here. I have a 99 150hp Johnson on my rig. It is a 6 cylinder engine and each cylinder has its own carburator. Last week while launching the boat, the check engine light came on a couple times and went right back off again. At the time the check engine light came on, the kid was idling off the end of the dock waiting for me to park the truck. Didn't notice anything unusual going across the lake except the motor seemed to be running a little rough but it sometimes will do that until it is warmed up. The check engine light was not on at this time. Later, when running back to the launch at the end of the day, we were running at 1/4 to 1/2 throttle until clear of the dead trees and the engine was running fine. Upon clearing the dead trees, we throttled up to go home when the engine just died, no warning, nothing, it just died, much like a motor would when running out of fuel. Knowing that we weren't out of fuel, the oil resevoir was full and we didn't hit anything, I trimmed the motor up to check the prop. There was nothing in the prop so we tried to start it. It started fine and the water pump was working normally but the engine was obviously running rough so we shut it off and used the kicker to get back. At this time, there were no warning lights on such as low oil and the oil resevoir was nearly full.

I took it to the local dealer to have it checked out and was told the #3 cylinder had frozen up. I was told the compression is less than 30. They feel it was probably due to the carberator for that cylinder running lean and thereby not getting any oil to the piston which caused it to seize up. They told me it is best to overhaul the entire engine because the labor to take the engine apart and fix the bad cylinder is about the same as doing the entire engine and because of what has happened, they said an entire overhaul is the prudent thing to do. The estimate to bore and re-sleeve the bad cylinder is about $3,000 and about $4,500 for the entire motor. Either way, I am done fishing for a while but;
1. Is this explanation plausible? Why wouldn't I have gotten a low oil warning or is does that apply only to the entire engine and not individual cylinders. The only warning we got was the very brief check engine light.
2. Is this repair estimate "in the ballpark" for this kind of work. I have never had this happen before.
3. Does it make better sense to overhaul the entire engine or just one cylinder. There really aren't very many hours on this engine. I only use it to travel between points A and B. The kicker and the electric motors do all of the fishing work. I do plan to keep this engine for a while yet. It has been problem free up until now.

[seahorse]

The CHECK ENGINE light tells you that there is a fuel restriction somewhere in the system and that the engine may be running lean, which could cause internal damage like yours has.

The dollar figure for you rebuild is a might on the high side, but that all depends on your shops hourly labor rate and what all new parts are installed. There are places that specialize in rebuilt powerheads with a warranty that may be an option for you, such as Flagship Marine Engines in FL and Riverside Marine. Your dealer should be familiar with these companies if they are an authorized dealer.

Make sure the other work is done also if you have a rebuild - water pump, thermostats, carb rebuilding, new fuel pump, fuel lines, filters, oil tank cleaned,etc. as most are 9 years old now. Have the mechanics do a vacuum and air bubble test on your boat's fuel system when the engine is done and being water tested.

[walleye710]

This information helps. Their labor rate is $100 per hour and they need at least 17 hours to repair the problem. The last time I needed work that is what the labor rate was anyway. They also quoted me $5,500 for a remanufactured power head. I suppose I will error on the side of caution and have the engine rebuilt but it will have to wait for a little while. I hit an underwater hazard at not much more than idle speed a couple years ago. Other than a very small dent in the propeller, I didn't think there was any damage but noticed metal filings in the grease when I changed it later. I took it in to have them determine where they were coming from and they found a couple of teeth missing on the gears in the lower unit which caused the filings that also apparently went through the bearings. $1,800 just to replace the gears at the bottom of the lower unit and bearings. Geez, and they say lightening doesn't strike twice.

Thanks for the response.

[seahorse]

With today's economy and boating slowdown, you may be ahead to find a later model used motor for about the same cost as your total rebuild. Parts of your old one are easily sold and can fetch over $1K. Don't overlook that possiblility.

[walleye710]

Thanks Seahorse, you make a very good point and one I'll certainly check into. I had not considered that. But with my son starting his senior year in college and my daughter her freshman year also in college, money is tight here right now. I'll see what happens this winter. In the meantime, I'll look for a buddy to take me along or wear out my waders.