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Messed up at launch, need motor help.


Sandmannd

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OK, I saw a couple of problems that look close to mine. I'm not as knowledgable as Fisherking01 sounds and don't want to steal GoldTip's thread.

Went up to Clear Lake last night. Got the boat all ready and the motor fired before launching. Put the motor all the way up and unhooked the safety chain. While I was backing it in the dude in the boat leaned over and undid the winch strap. I didn't realize this (have done it in the past, but only at even launches) and I was backing it in. I started hitting the bumps on the launch and boat came off and hit the ground in about 18" of water mad . I was a little chapped. Got the boat in and dude in the boat started it up and waited for me to park. Got it parked and in the boat. Motor was purring fine. I turned out to the lake and put the throttle down. It jumped up on plane right away. Was running for a few minutes and the motor started to loose power and then shut off.

It's an '02 merc 75 hp. Tried starting it and it would fire and run for anywhere between 10 seconds and 2-3 minutes. Took the top off and checked around (keep in mind when it comes to motors my 2 yr old probably has more knowledge than I do). Check the plug cables and on one of the plugs the tip (not sure what it's called) had broke off and was inside the cable. I got that out and luckily had my old plugs in the boat. The plug that was in there seemed wet. I put the new one in and it fired right up and ran for about 3 minutes. Went to throttle and it reved down and died again cry .

We started drifting and doing a little fishing. I was running the trolling motor and would periodically try to start the motor. After a while of doing that everytime I would try to start the motor the fish finders would shut off so I figured the battery was running low. We trolled in and loaded up. I have a nice dent in the bottom of the boat right on the center of it below the drian plug mad but it doesn't appear to be leaking so I guess I can live with that.

Went out today and put the earns on the garden hose. It fired right up but again only ran for about 3 minutes and then died. Same thing again, it would start and run for a little and then stop. I checked the oil and it's full, I went to put gas in (wanted to make sure I wasn't an one-who-thinks-I-am-silly and running low on gas cool ) and it only held two gallons.

That's all I've done so far. Any suggestions would be great. Is this something you think I would have to take it in to get fixed?

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It's got an inboard tank. Not sure where that would be. I talked to my Dad on the phone who is a good 2 stroke mechanic but lives in ND and he said it may be the needle and seat. I kinda wonder if it isn't the bulb on the fuel line. Anyone know if I'm near the right track here?

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Shane, when you say you fired it up before launching, how long did you run it? Enough to fry the impeller? Did you notice if it was pumping water at all? The first thing I'd do is compression test.

It sounds as if it either heated up and squeaked or is running out of fuel. Did you have to pump up the bulb to get it to fire again? I'm not trying to scare you, but the part that concerns me is firing it up at the ramp out of water.

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It could be a number of things. One thing could be fuel pump. I dont know how to check one but if it is dont start it and run it .It will run to lean and possibly run to hot and melt piston. thats what happend to my Yamy 150.

I could be a bad sensor shutting moter down. Hopefully its that simple.

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I agree with the ST above, and Boatfixer, and I really hope for you it is not the worse scenario...

Do a compression test, then if it's ok replace the impeller and check motor again.

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Sorry I miss typed. I didn't start it at the ramp. I just turned it over to make sure it was firing. I connected the ears to it yesterday and fired and had it runnin for 15 mins. Shut it down and waited a bit and it fired and ran again. Took it out this morng and won't stay running. Not sure how to check compression and it is shootin water fine.

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Thats good to hear Shane,(about not running it out of water) Look at the top of the boating page for details on how to do a compression test. Hopefully it turns out good. Then I'd start looking at the fuel supply. Have you checked for spark on all cylinders?

Spark

Compression

Fuel

Exhaust

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Sounds more like it's running out of gas. Try to pump the primer bulb to keep it hard and see if it runs longer. Also try to play with the choke to see if that helps. If any of that works it could help to to see if it's the fuel pump/hose or in the carbs.

Have you had it out prior to that this year? If so, how did it run?

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Sounds more like it's running out of gas. Try to pump the primer bulb to keep it hard and see if it runs longer. Also try to play with the choke to see if that helps. If any of that works it could help to to see if it's the fuel pump/hose or in the carbs.

Have you had it out prior to that this year? If so, how did it run?

I put a new fuel line on it today and the ball stays tighter but still have the same problem. I've made sure it was on the right way. Pumping the bulb did seem to help it yesterday with the ears on it, but not today. Haven't played with the choke yet, that's worth a try. I've had it out about five times prior to this happening this year and it's run like a champ. Just started doing that after it fell off the trailer, don't know if that had anything to do with it or not. Thanks for all the advice so far guys. Much appreciated.

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Hard to see that the mishap and the landing and the motor problem are directly connected - except - the line may have gotten plugged that lets the water in to the water pump or you may have sucked in some junk that plugged the outlet. If it runs for 2 minutes you have to have spark. Is there water coming out of the right place on the motor when you start it up with the muffs on? If not then you have to check the inlet and outlet for obstructions - piece of wire or compressed air will help. If this still doesn't work then you most likely have to repair the impeller in the water pump or replace the pump entirely.

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Water runs fine through the motor so that's not it. Anyone know a good place to take it in? I was thinking either Maplewood Marine or Roseville Auto and Marine but open to any suggestions. This is the first time I've had motor probs on a boat so I have no experiene dealing with a shop.

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not knowing what kind of boat you have, or how it is laid out, is it possible that the dent in the bottom of your boat is the bottom of the gas tank ? In which case, the bottom of the tank is now pushed up against the fuel pickup tube, restricting fuel to the engine. Is the engine carb or efi ?

Don .

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but the part that concerns me is firing it up at the ramp out of water.

Why can't you fire it up for say 10 - 15 seconds out of the water? Especially if the engine is cold. I can't believe the engine is going to heat up in that short a time to do any damage.

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Originally Posted By: boatfixer
but the part that concerns me is firing it up at the ramp out of water.

Why can't you fire it up for say 10 - 15 seconds out of the water? Especially if the engine is cold. I can't believe the engine is going to heat up in that short a time to do any damage.

It's not the engine warming up the problem is running your water pump dry the big issue.

Your impeller is a rubber wheel rotating against a stainless steel surface.

Get down on your knees on a floor carpet then have somebody drag you along very fast, what happens ? Rug burns, well that's what happens to the pump, it will melt the rubber. Water lubricates the vanes and cools the rubber.

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i'd say your head gasket is shot, same thing happened to me last year. A compression test by someone who knows how to do it is where I would start. Bring it in, it'll be worth the hassle.

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Just for the heck of it check the lower unit oil level. While your down there look for a cracked lower unit or bent prop shaft.

If that all checks out then we(you) have to determine if its starving for gas or flooding out. Pull the plugs after the next time it acts up.

I'd like to see the fuel filter and a sample of gas. Siphon some gas into a clear glass container. Is it cloudy and are there any swirls?

About the dry start, as Val said the impeller is rubber, the inside pump body is stainless steel. The impeller turns at the same RPMs as the motor. A few dry seconds at 800 RPMs is all it takes to damage the impellor.

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