mr. 12 footer

[ashcroft]

12,<br /><br />Thanks to your help we've now got the boat running properly... she idles at a nice 1800/2000 rms and starts cold with just a 5 second key turnover. Everything seemed to be in order... i thought...<br /><br />Problem 1. as soon as we get the throttle pushed about 1/2 and 3/4 of the way down (about 4000rms) we would encounter an engine sputter. It actually would decrease in power as we "inched" forward with the throttle. Could this be gear trouble? or is it just something once again with the gas intake?<br /><br />Problem 2. Once i finally managed to get the pretty thing up and in a plane (5500rpms -- as you said) she ran fine... never showing any sign of waivering or distress. However, coming out when we pulled back the power she seemed to down shift quicker than to be expected... to the point of causing the wake to engulf 3/4 of the motor...ultimately causing her to die. This process was repeated about 5 times in a two hour period. Every time -- When restarting she would not stay idle unless the choke was once again placed upright (50%). Now am i just an idiot and not know how to bring my boat to a pleasant "no wake" progression... or could something else be causing this problem... Also, today we had 3 persons in the boat as opposed to either 1 or 2... adding about 200lbs to the total weight...could this be a factor?<br /><br />side note: Once out of the water I pulled the plug to see, to my astonishment, most of the lake drain from my boat... do you think it was caused by repeated drowning of my engine?<br /><br />Thanks in advance for any insight you might have.. or anyone else... <br /><br />78' Cajun<br />85hrp Mercury<br />Degected "first mate"<br /><br />ashcroft

 

[ashcroft]

Re: mr. 12 footer

back to the top

 

[12Footer]

Re: mr. 12 footer

ooopps..Sorry. I skimmed right over this.<br /><br />Problem 1. as soon as we get the throttle pushed about 1/2 and 3/4 of the way down (about 4000rms) we would encounter an engine sputter. It actually would decrease in power as we "inched" forward with the throttle. Could this be gear trouble? or is it just something once again with the gas intake?<br />If it is acting like a slipping clutch on a car, you may have cavitation or a spun-out hub.<br />If the prop catches water with air bubbles in it, it will slip, causing cavitation. Look for a dent in the hull, a protrudence (barmnicles or rivets), disturbing the water flow over the prop.<br />Second, take some fingernail polish, and paint a single line from the prop nut, straight-out to one of the blades. Run it. It the line breaks, missaligns itself, the hub has spun. Remove the prop,and have it re-hubbed at a prop shop (about 35-40buks).<br /><br />Problem 2. Once i finally managed to get the pretty thing up and in a plane (5500rpms -- as you said) she ran fine... never showing any sign of waivering or distress. However, coming out when we pulled back the power she seemed to down shift quicker than to be expected... to the point of causing the wake to engulf 3/4 of the motor...ultimately causing her to die. This process was repeated about 5 times in a two hour period. Every time -- When restarting she would not stay idle unless the choke was once again placed upright (50%). Now am i just an idiot and not know how to bring my boat to a pleasant "no wake" progression... or could something else be causing this problem... Also, today we had 3 persons in the boat as opposed to either 1 or 2... adding about 200lbs to the total weight...could this be a factor?<br /><br />This could be several different problems instead of one.<br />First, you should only back-off the throttle quickly, when it is absolutely nesessary. Allways plan your movements at the helm ahead of time whenever possable.<br />Most outboards are capable of allowing water over the transom by quick back-downs.<br />Then again, you may be over-powered, and the motor is simply too much for the hull design. Look for a coast gaurd sticker(usually, a bright yellow) by the helm that gives the hull's max HP. If it is missing suspect overpowered hull at the onset.<br /><br />Wieght of passengers and cargo are also a matter of the boats abilities to carry said wieght. The CG sticker will also advise the max allowable wieght/passenger capabilities. Again, if missing, don't guess. Look-up your boat manufacturer online, and see if they can give you this information. They (if still in buisness) are obligated to do so.<br /><br />Lastly, the taking-on water issue....Bad news regardless of where and how, but before placing her back into the water, find out where and how.Don't risk a sinking. Outside of the obvious threat to life and limb, is the environmental chaos sinkings cause, all of which the boat owner is liable for. (In other words, it gets expensive).<br /><br />Look the hull over very carefully, for any signs of cracking. This mostly occurs allong the keel, or at the transom. Make sure the drain hole plug is in and seated properly before each launch.<br /><br />And finally, all new boaters should take a safe-boating coarse before going out. Us 'old salts' are lax about urging new boaters to do this, and it's the most important prep-step for all of us.<br />Check the web for a safe-boating coarse near you that you can attend, or take one of the many state-sponsored, online coarses. Here is one such site that is really good, free, and informative.<br /> State of Florida's Online Safe-Boating Coarse