No Power/Just idles

[Grant Brown]

70 Merc 3 Cyl serial # 0A739874<br /><br />I finally got my boat in the water today for the first time ever and had some troubles. <br /><br />I did a totally dumbass move and ran it onto some sand. The area is known as mud bay and at low tide there's lots of almost exposed mud.<br />Anyway I was only at an idle speed in a now wake zone and immediately raised the leg and got back in the deep water. <br /><br />I lowered the leg and then continued on my way, still at idle. When I was clear of the no wake zone, I opened it up and is took off just fine and then all of a sudden the throttle died and all it would do is idle all the way back in. The idle was rough and it died several times but re-started immediatly each time except for once but then started again after a cuople of tries.<br />It almost felt like the gears weren't totally engaged too but maybe that's how it feels in this boat at that rpm.<br /><br />Thanks,<br />Grant

 

[Grant Brown]

Re: No Power/Just idles

bump

 

[mellowyellow]

Re: No Power/Just idles

if you plugged the cooling system with sand/mud,<br />it wouldn't take long to overheat and die. first<br />step is pull the lower unit, check condition of<br />impeller and look for blockages.<br />good luck,<br />M.Y.

 

[schaiss]

Re: No Power/Just idles

Before pulling the lower unit, try pulling open the coling water line where it exits the top of the engine. Keep a section of the hose on the fitting at the top of the engine (to direct the stream of water away from the engine). Have someone hold this disconnected hose, then with muffs on the engine fire it up. At idle you should get a very strong stream of water pumping out of the hose, if not you will have to pull the LU and replace that water pump impeller (about $15, or $40 for the entire water pump).

 

[Grant Brown]

Re: No Power/Just idles

The cooling system was still pumping lots of water out the back while idling. It just wouldn't go from bare idle to high rpm. When in neutral the high idle lever would increase rpm but nothing from the main throttle lever while in gear. In hindsight it almost felt like the throttle cable came undone or something.

 

[Yepblaze]

Re: No Power/Just idles

Sounds to me like you may have<br /><br />spun the hub in the propeller giving that stripped gear feeling<br /><br />And perhaps at the same time stumbled upon an existing or newly developing fuel starvation issue, (tank,hose,connector,fuel pump, carbs, or watrer in fuel)<br /><br />That's not to say that your situation might not be ignition related.<br /><br /><br />I know this is a very broad overview but those are the areas you may want to consider.<br /><br />If you know the diagnostic procedures it's not all that overwhelming. If you want to be your own mechanic you're going to want a good repair manual.

 

[jim dozier]

Re: No Power/Just idles

Even with a spun prop hub the engine will run fine and rev up just fine you just won't go anywhere above idle speed. You said that intially the engine took off OK then suddenly dropped back to a rough idle. I suspect either of 2 things happened.<br /><br />1. Something in the idle linkage came undone and either the carb butterfly or ignition timing lever (or both) are not advancing with the throttle lever in the boat. <br /><br />2. More likely crud in the carburetor has come loose and clogged the main jet in one or more cylinders and the engine is running off of the idle circuits.<br /><br />Take off the engine cover and verify that the throttle linkages are all working like they are supposed to. The carb butterflies (throttle plates) on each carb should be advancing in unison. The ignition advance lever should be advancing the ignition all the way on full throttle.<br /><br />If there is a drain plug on those carbs, unscrew it and drain the bowls on the carbs and check for crud. Try spraying a a little premix fuel from a spray bottle into the carb throat when it is acting up and see if the engine picks up. You may need to remove the carbs and do a thorough carb cleaning/rebuild.

 

[vinney]

Re: No Power/Just idles

Is this the first ride of the season? Check to see if the trigger is moving. Sometimes the trigger gets tight over the winter.

 

[Grant Brown]

Re: No Power/Just idles

I finally got the boat back home and when I opened the cowel I noticed a part of the linkage was disconnected. I'm trying to do all of the testing by myself so it's pretty tough so see whats going on with the linkage from the front of the boat. <br /><br />When I replace the linkage and then move the throttle it pops right back out again so it looks like there's some sort of retainer missing or broken.<br /><br />I took some photos and I was wondering if someone could have a look and tell me if it looks like it's all there and if it's set up correctly.<br /> http://www.grantbrown.ca/boat/index2.html

 

[vinney]

Re: No Power/Just idles

Great photo's. It looks like your throttle linkage. That is what move the throttle linkage on the carbs. Moves the throttle plates open.

 

[randycc58]

Re: No Power/Just idles

i suggest you take the photos up to your marine dealer with the modle and serial #. he will be able to get the part for you and give you a print out of the parts page which will show you the proper location of the linkage. Also the manual is of great use.