MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

[jcac27]

Hi,<br />I am really trying to keep the cost of maintaining my boat, trying to do as much work myself. I winterized and will change engine and lower unit oil in a month when it gets warmer. More info: 1990 galaxy with 3L mercruiser with an alpha one. The engine runs well when I am just running, but if I try to go from neutral to full throttle, like trying to pull up a skiier, it bogs down and stalls. It doesnt happen at all if I give it gradual gas. Are there any easy fixes that might help. I dont really know what I'm doing and suspect you experts are going to say rebuild the carb, but I cant do that. Any ideas? Also, while Ive got your attention, it is tough to get this baby to start after its been sitting all week. It starts, then sputters out. Ive got to do this maybe 8 times till it finally fights through the sputters and idles. Ive already had to replace the starter once(broken teeth) and would rather not do that again. Any ideas on this one? Is that the wires or plugs or something I can do? <br /><br />Thank you very much for your help.<br /><br />James

 

[Walt T]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

I tell you what you don't want to hear.<br /><br />The carb is gummed up, especially the secondary jets.

 

[ae708]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

I had basically the same problem. My boat 17'9 Manta Ray with 3.0 Mercruiser I/O would bog then when it was at WOT I was down about 800 RPM and a LOT of speed. I removed the old gas from the tank, put in 10 gals of high test and a can of SeaFoam fuel system cleaner. After about 20 minutes of running the boat , goosing the throttle at WOT it all of a sudden took off and was running 4900 RPM at 48 MPH. right where it ran when it was new. I learned about letting my gas get old.

 

[Bondo]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

You've Most Definitely got a Fuel Issue..........<br />Unfortunatly, All of the Fixes are Probably out of Your range of Wrenching........<br />Fresh Fuel is Important, as stated by ae708......<br />Fresh Filters are something You could do......<br />After that, It's on to a Carb. rebuild, Fuel Pressure Check, Etc........<br />It Appears Both(Bogging,+ the Hard Starting) of your Problems are Probably Related..........<br />Sorry,<br />Looks like it Might be time to find a Quality Mechanic......................

 

[rodbolt]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

hello<br /> yep but remember the mer-carb was and is very problematic, its a beast sometimes. the little filter under the pump never gets changed. be aware if you break the screw and have to cut the band you cannot buy just the band. I would recommend a carb job for the bogging problem. what you describe is normally accelerator pump discharge problems. post us your starting procedure as well. if its correct we can tell you, if not correct maybe we can help with that as well.<br /> good luck and keep posting

 

[jcac27]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

Thanks for the quick responses and help.<br />Ok, after looking around more at previous threads here, Ive found carb rebuild kits for about 50$ and remanufactured carbs for about 225$. With very little experience can I do either of these? I'm very handy and have the shop manual somehwhere for my engine, but have little experience messing with car/boat engines. I can change lower unit and engine oil, but have done little more. Which might I have a chance doing myself? Should I bother? Should I just pay someone to do it? Can I get it done for somewhere in the 200$ range?<br /><br />I also read in another posting that it could be my accelerator pump. Could that be the whole problem? Can I fix that? <br /><br />Lastly, my starting procedure:<br />I push the throttle handle all the way down about 4 times then try to start it. When it sputters and dies, I do this again. Keep doing this till it fights through and idles. Is that right?<br /><br />Thanks again.<br /><br />james

 

[Walt T]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

There are four circuits on a carb. Idle, choke, acceleration and power. You have problems in more than one circuit.

 

[jmattor]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

Walt, Bondo & Rod are right. Old fuel, dirty fuel, varnish build-up in the tank that may have been disturbed or dissolved then stratified and into your fuel pick-up. Now the accelerator pump is gummed up and probably more stuff to clean too. Clean everything from the carb back, screens, etc. Change filters. If you don't have a fuel/water separator you might want to put one on. They are cheap and do the job. Check out www.carbcareusa.com for a rebuilt. Last time I checked it was $175.00 or so plus your core deposit of $50 for the Mercarb.

 

[crazy charlie]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

Jcac27,always try something simple first when you are unsure of the source of the problem.What I would do is drain whatever fuel you can and replace with some premium fuel and a can or 2 of seafoam(napa $6.99) then replace the fuel/water seperator,then replace the filter in the carb.While replacing the carb filter check the choke.Make sure it is hooked up.If it is not then wire it open.Then change the plugs.This is all simple stuff that anyone can do.See if it makes a difference.If it does not then you have done some routine maintenance and gained some experience.Now you can look into paying someone or attempting replacing the carb.Everyone gets lucky once and has a simple fix.And the luck is usually only ONCE!!Charlie

 

[rodbolt]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

hello<br /> and dont forget . if it has a mechanical fuel pump the pump has a filter as well. it causes problems that never get fixed <br /> good luck. if your afraid to dig into the carb take it off and have it done. its a straight fwd carb. worst you will be is haveing to buy one anyway. its a slightly redesigned rochester 2bbl. proper starting also will have you leave the trottle advaned far enough so that at start up it will idle between 1100 and 1500 rpm.<br /> good luck and keep posting

 

[jcac27]

Re: MERCRUISER 3L W ALPHA ONE BOGGING DOWN FROM IDLE TO FULL THROTTLE...

Hey,<br />This is going to be a long post so please bear with me and thanks for the help. Im determined to get this done and learn this stuff at the same time. <br />OK, I removed and replaced the fuel/water filter. I took the fuel pump off to change the filter(as it said to do in my service manual). This boat was left out in the rain so many of these parts are rusted togethor. As I tried to loosen the screw on the bottom, the two arms that hold the bell in place broke and it all fell out.(Ill save all questions till the end)<br />Then I disconnected the yellow flexible tube that goes to the carb and found that to be almost completely closed with a brown gunk. I cleaned that out and took off the fuel filter. <br />Then I went to change the filter on the fuel line into the carb. When i got that off I found just a screen type filter that had what looked like some sand in it. I cleaned that out and assume I can use that again as it looked clean after I got the debris out. <br />Questions:<br />What is the yellow flexible line for? Why was that gunked up so badly? <br /><br />Where can I get a new one of those arm type tighteners for my fuel pump?<br /><br />The fuel line between the fuel pump and the carb was deteriorating and bent a bit more than I would have liked when I went to get to the filter by teh carb. Where can I get a new one of those and what is that piece called?<br /><br />The soapstone type filter in the fuel pump doesnt look to be iin bad shape. Should I replace this? Where do I get one?<br /><br />What other suggestions do you have? <br /><br />Thanks alot for everyones help. This is a great source of info.<br /><br />James