Used Boat Test Drive -- Issues

[jwharan]

I test drove a boat yesterday that I am buying. I have a few issues that I could use some help with.<br /><br />First, The boat starts and idles properly, but tends to stall when I try to go into gear. Even if i throw the gear down hard, it wants to stall about 50% of the time. I want to say the engine just sounds like it is running way to rich. Once I am in gear, and moving around, the boat runs great.<br /><br />My next question is probably my misjudgement and not the boat. First, i am not sure how to use Trim, Should it be up down or in the middle? when do i need to adjust it? 2nd, If I accelerate beyond a certain point, or too quickly, the boat seems to "spin in place" the RPMs shoot up, but the boat doesn't go anywhere. I have to throttle down to almost neutral, in order to regain momentum. Also, sometimes the boat will shake when I accelerate to fast, perhaps this has to do with my trim setting, not sure. Can anyone offer some advice to my issues here? Thanks!

 

[milkyway]

Re: Used Boat Test Drive -- Issues

Just for testing the boat, keep the trim all the way down to keep it simple for yourself. If you have it at the wrong angle, you may experience problem accelerating from a stop position. But until you get to get the engine to run correctly, the boat may not plane at all, or just barely planing but without enough power to continue. If the boat shakes when you are accelerating, could be engine. You must first have the engine run 100%. If the trim works up and down, then the trimp is working. That should be your concern for now about the trim. <br /><br />Can you give more details about this boat?

 

[GarySutherland]

Re: Used Boat Test Drive -- Issues

I'm assuming from what you've said that it's got an outboard motor. Have you checked the engine is suitable for the height of the transom? i.e. short-shaft/long-shaft?<br /><br />It sounds as though at full throttle the engine is running out of water, suggesting that the engine is too short for the boat.<br /><br />My own boat suffers from this and I believe it to be just this; short shaft engine and built-up transom more suited to long-shaft.<br /><br />Cheers<br />Gary

 

[jwharan]

Re: Used Boat Test Drive -- Issues

The Boat is a sea ray 185, 4.3 merc 190hp 18.5. Boat planes fine. The trim does work, i just don't how to use it. What else do you suggest, what about the "spinning out" problem?

 

[txswinner]

Re: Used Boat Test Drive -- Issues

Get compression checked on all cylinders, because I have limited knowledge I always have boat checked about $100 to $150 by boat motor mechanic, good luck.

 

[jwharan]

Re: Used Boat Test Drive -- Issues

Does anyone else have any comments on any of my other issues? In addition, the speedometer, is not working.

 

[KCook]

Re: Used Boat Test Drive -- Issues

Stalling when going into gear and the boat shaking should be your number 1 concerns. The other is minor stuff. As txswinner already said, need to have a professional look at this.<br /><br />Kelly Cook

 

[umblecumbuz]

Re: Used Boat Test Drive -- Issues

Hi Jwharan,<br /><br />This 'spinning out'. it sounds like the prop is pulling air, from the way you describe it. You say you're not sure how to trim. This could be as simple as having the outdrive trimmed out too far. <br /><br />Do as Milkyway suggests - trim the outdrive all the way in (propellor nearest to the transom), and give it another run.<br /><br />The stalling when engaging gear could also be simple, such as a mixture or slow idle adjustment.<br /><br />Ain't anything wrong with grabbing a mate who's used to boats and getting him to go along with you.

 

[jwharan]

Re: Used Boat Test Drive -- Issues

Originally posted by Stillfishing:<br /> Hi Jwharan,<br /><br />This 'spinning out'. it sounds like the prop is pulling air, from the way you describe it. You say you're not sure how to trim. This could be as simple as having the outdrive trimmed out too far. <br /><br />Do as Milkyway suggests - trim the outdrive all the way in (propellor nearest to the transom), and give it another run.<br /><br />The stalling when engaging gear could also be simple, such as a mixture or slow idle adjustment.<br /><br />Ain't anything wrong with grabbing a mate who's used to boats and getting him to go along with you.

StillFishing:<br /><br />I think you are pretty on with this. can you talk about the spinning out part a bit more. If i was to describe it more, I would say that it feels like knocking a car into neutral, while accelerating. The RPMS jump way up, and the speed drops off.

 

[txswinner]

Re: Used Boat Test Drive -- Issues

In boating it is often referred to as cavitation. It is when the prop is sucking air and increases rpm without water to increase accelaration of the boat. The motor needs be trimmed all the way down to the stop. This should eliminate the problem. If not you should have the prop checked as it may be damaged.