Whaler Central - Boston Whaler Boat Information and Photos

Posted by cleep1700 on 05/14/15 - 4:51 AM

Bought my 1978 last fall and it came with a Mercury 50 hp. Had Bass Pro go through the engine and they cleaned up the carbs among other things. Took it out for it's first run recently and noticed that the engine seems to lag when I am half way to full throttle. A couple of times it stalled. I fired it back up and then slowly moved the throttle forward, it would reach the half way point, gurgle and grumble, and then slowly it would recover and the engine would sound as if it were running on all cylinders. Had this happen intermittently during my two hour run. Is this normal for an old engine? My boat is a 1978 and the engine is close to the same vintage. I took it back to Bass Pro at the end of the day and he said it sounded like the injectors(?) might be plugged up and an additive to the gas mixture is a possible solution.
Craig in windy Kansas

Edited by Joe Kriz on 05/06/16 - 2:41 PM

Posted by Clyde in TS on 05/14/15 - 6:19 PM

Have you done a compression check? Have you run the engine out of the water? Running an old Mercury out of the water will cause the top cylinder rings to bind and you will be running on 3 cylinders. lAlso, a long time outboard mechanic told me that the Mercury 50 hp 4 cylinder (aka "504") is a very hardy and tough block, but has one weak spot. Check to see if the screws on the distributor advance have been backed out. If there is still a reasonable amount of adjustment in the distributor advance, then the problem is likely in the carbs. (I have a "504"). be sure to keep a good, clean, impeller pump in it and do not run it out of water! (don't ask me how I know). PS, the old Mercury outboards were rated for hp at the engine, not the shaft - so you would have a 40 by today's standards

Posted by wlagarde on 05/14/15 - 7:46 PM

cleep1700 wrote:
Bought my 1978 last fall and it came with a Mercury 50 hp. Had Bass Pro go through the engine and they cleaned up the carbs among other things. Took it out for it's first run recently and noticed that the engine seems to lag when I am half way to full throttle. A couple of times it stalled. I fired it back up and then slowly moved the throttle forward, it would reach the half way point, gurgle and grumble, and then slowly it would recover and the engine would sound as if it were running on all cylinders. Had this happen intermittently during my two hour run. Is this normal for an old engine? My boat is a 1978 and the engine is close to the same vintage. I took it back to Bass Pro at the end of the day and he said it sounded like the injectors(?) might be plugged up and an additive to the gas mixture is a possible solution.
Craig in windy Kansas

I had similar engine behavior after I upgraded my engine to 50hp (http://www.whalercentral.com/userphot...lbum_id=65). Before installing the carbs I had cleaned them with gumout and rebuilt them with new seals, floats, etc - yes I was frustrated!

I pulled the carbs back off and fully disassembled them again. I found an ever so small piece or crap lodged in the main jet of one of the 3 carbs. This time I ultrasonically cleaned them and reassembled. I then flushed the whole fuel system and installed a fuel/water separator/filter. When I fired the engine up again the problem was gone. Lesson learned - it doesn't take much to partially clog the jets in a carbureted engine.

Edited by wlagarde on 05/14/15 - 8:01 PM

Posted by cleep1700 on 05/06/16 - 4:38 AM

Two years ago I bought my first Whaler, a 15 footer, but had problems with the 50 hp Merc. The motor gurgled and stuttered when I pushed the throttle forward halfway between neutral and wide open. I ask the forum for advice and I wanted to let you know the outcome. Originally I took it to Bass Pro to be worked on, for it was close to my home, and I was a newbie who thought that they would solve the problem. However, the techs there are all very young and clueless about carburated engines....just billed me for outrageously for nothing. Somebody recommended that I find a mechanic who was older than the engine, this one a 1978. Well, I'm telling you that I did just that and now my Whaler is the boat that I dreamed about. Splashed it yesterday after winter work by my new found genius mechanic and it runs like a top: wot 33 mph by the indicator on my Humminbird and a motor that hums without a hitch. I couldn't be happier! So my advice to fellow newbies...ask for advice on this forum and you will find friends who have the correct answers or can lead you in that direction.

Edited by Joe Kriz on 05/06/16 - 12:43 PM