I test ran a boat that I expected to buy. Engine made me nervous so didn't.
2005 150 Johnson c with fewer than, reportedly, 100 hours. It looked great. Clean and shiny inside and out.
Engine would start but kept shutting down. Got it in motion and it ran fine at fast idle. It had a great hole shot, was fast on plane and speedy.
However, when I slowed it down there was this terrible rattle and clatter that made me feel that it was ready to jump off of the transom. Marine dealer says it is normal for that engine. All he had were just like it. I tried it a number of times and it was always there. Maybe that is the way a 150 sounds when quickly brought to idle speed. I've only had an old 70hp prior to this and that one did not have that sound. Can anyone tell me about this?
Engine would stall at idle or in neutral or reverse.
Mechanic came down to take a look and it wouldn't start. Pulled it out and back to shop to discover that it needed a carberator job. They were willing to pay for that and continue deal but I was nervous and bowed out.
Could be that it simply needed an idle adjustment and a carbeurator job and would have been perfectly fine. But they had recently serviced it. I know that an engine can one day be fine and the next day have a fixable problem - usually on the day I show up - but it made me uncomfortable.
But the biggest thing was that loud rattle and clatter. Whether or not the rest was fixable this was not and it was unacceptable to me. Should I stop looking for carbeurated engines and stick with 4 stroke?
One other thing. It had a tremendous torque pull to the right (which other way would it go?) that required definite pressure on the steering wheel to keep it straight. I would expect some but how much is too much? Was it just my lack of familiarity with this powerful an engine on 18.5 ft boat?
Location: Port Charlotte FL (almost -- its coming along)Never mind - it'll never be the same
Posts: 15,669
Re: Picked up new boat - well, almost did
The carb job will probably take care of the idle run issues.
If you chop the throttle quickly on some 60* motors (like that one) it's possible to get what the OMC engineers called a "decel knock". On hard deceleration you'll hear what sounds like severe piston knocking. Yes, it's loud and scares the puddin outta you. It won't be there on a slow deceleration. If you bump the primer it'll go away too. Cooler plugs seem to help too.
It really doesn't hurt anything but it's hard to convince folks of that. When OMC left the scene they were working on a switch that automatically engaged the primer for a split second when the throttle was pulled back.
The bottom line is that design is one of, if not the best OMC had. I wouldn't be afraid of it but if you are the least bit concerned, pass on it. There are lots of good deals out there right now.
Now, that's what it can be. It may be something else but I have heard the dreaded decell knock.
Basically you are saying that a carb job should solve the problems with starting and idling. The decel noise is normal and probably of no concern mechanically. Given that info I might reconsider my position on this boat.
The engine (reportedly) has about 100 hrs on it and was completely serviced about 8-10 weeks ago, taken out for one farewell experience by owner with his kids, and then put on the market. At that time it ran perfectly.
Why would it suddenly, after servicing, have a carb problem?
As an aside (and probably of no help at all) when it wouldn't start the mechanic checked the spark which was ok. He then pulled a screw plug from the right front of engine and some fluid leaked out. From where I was standing it looked thin. He then looked at the screw as if it would tell him something and concluded that the engine needed a carb job.
Location: Port Charlotte FL (almost -- its coming along)Never mind - it'll never be the same
Posts: 15,669
Re: Picked up new boat - well, almost did
When fuel sits it turns to varnish. The oil in the gas will accelerate that process. 8-10 weeks with unstabilized fuel can, and often does, create the need for a carb bath. It can happen sooner.
What he looked at was, most likely, the plug covering the high speed jet in a carb bowl. The fluid was (obviously) fuel & oil. He'll look at the inside of that plug. If it has varvish or "scum" on it he'll know the inside of the carb is like that and needs a bath.
Personal opinion - if it were me I'd let them do whatever they felt necessary to make it run correctly and take another ride (any excuse to get out on the water). If it idles properly and accelerates right, fine, good job. As for the decell knock, I'd decelerate slowly or normally. That should cure that problem. If decelerating slowly still produced a noise, I'd look into that further. Maybe walk away.
Agree with Dhadley.I would request a compression reading on all cylinders.They should do that for free.Takes about 15min.Possibly they saw water weep from that screw you spoke about.Be sure they check the tank for water.You scould have a fuel/water seperator installed ,if none present.If present,have them drain and check for water.Condensation can build up in fuel tanks ,or rain may find its way,also the tank or fill can allow water.The seperator is similiar to an automoitve oil filter,easy to remove,dump contents in a jar and look for any water ,it will appear like oil vinigar salad dressing when seperated.if the price is right and you LOVE the boat.Give it another shot.
I think I neglected to mention that this boat is 500 miles away from me. I am reconsidering but, at the very least, will expect them to deduct my wasted travel expenses from my original offer. I want them to test the boat/engine and insure that it runs out the way it should.
I would like to very specific about what I expect from that engine and will want them to demonstrate, in my presence, compression - and anything else that is important.
I would like you folks to tell me what I mean when I say important. Help me develope a list.
Myself, I think you're expecting a little much on the travel expenses. It's not their fault you live so far away. But, if they go for it, good for you.
I don't think they'd have any problem with you standing there watching the compression test. It's quick like they said. I'd be suspect of any cylinders that weren't VERY close to the others in a motor that new. I wouldn't think you should see any more that 5 lbs. off, and for sure not more than 10% of the total compression.
I'd look at compression, make sure it idled nice and smooth and about 650 to 800 RPM's, shifted smooth and stayed in gear. Remember, you should go into gear nice and quick with the throttle shift, if you go slow it's going to grind even on a brand new one. After a ride and if I were satisfied, I'd ask if they would crack the lower unit oil drain plug and let me see the oil--or water if it leaks.
If it has a trim tab I'd ask them to adjust it to take the steering pull out. It may not have one though. I know on an engine that powerful, there's often a little torque steer but it shouldn't be bad. I'd also pay special attn. to how smooth the power tilt worked and what it sounded like.
It may be that the carbs. were dirty because the previous owner never used it and as long as he didn't run it lean, that would be a good thing--verifying it didn't get used much. Also make sure it's pumping water good by looking for a STRONG stream of water out the tell-tale. I'd think at 1000 rpm's it would go in a straight line into the water.
Is there any warranty on the boat at all? 30 days? I'd think that would be reasonable buying from a dealer or I wouldn't pay a dealer price. I'd also try to see if you could slow down at a reasonable rate and see if it affected that rumble you were speaking of. I personally don't like to throttle completely off from wide open even on my smaller motors. They don't like it.
By the way, I don't run too many motors over 40hp. I find 60mph on the water a little disconcerting, although fun. And they like the petrol!
So keep that in mind as far as the reliability of my post.
Don't forget to look at the bottom of the hull for boogers, and look for cracks in the transom as well. Check the bilge after the run for water and don't slow down so fast that water comes over the transom and puts water in the bilge. And if you're towing it home 500miles, feel the hubs after you get to the lake for the test run and if they're hot.........
Show us some pics if you get your boat...
Good luck,
JBJ
You may be right regarding discount for expenses. However, I had lengthy discussions about those things I was most interested in/concerned about and we discussed that I was coming a considerable distance. They assured me that everything was in perfect running order and that travel expense was a good investment on my part.
On the one hand they couldn't predict that it would need a carb job. On the other hand they relied on their knowledge that it had been serviced in past few months (or so) and did not bother to actually check anything prior to my arrival.
I think that I can make a case. We'll see.
Thanks again. I am printing your advice because I believe that it will come in handy in a general way in the future no matter what boat I pursue.
Picked up new boat - well, almost did
And they like the petrol!
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