When will it end.. Compound probs with Merc

[boaterntexas]

Every time I take the boat out I find a new problem, what can I do to have a working reliable boat motor.. <br /><br /> motor info: 115 hp merc. Year. 1976 Serial. #4570020. with thunderbolt. since buying the boat 3 mounths ago I have replaced the impleller, and had the prop rehubbed.<br /> We have been having so gas use and performace problems, so I decided to change the plugs the ones that came out look like regular automotive plugs with the gap on the end, they where in bad shape, and looked like they had been burnt up and had lots of oil residue on them, 2 of the plugs where in better shape then the rest, but still not good. The place where I bought the new plugs said their book showed a plug that did not have a gap, it had a surface gap on it, so I went with thoose, Out of the water it seemed to be an inprovement, the motor got up to higher RPMS, and started easier. I took the boat to the lake today, for the first part of the day everythign seemed to be working real well. we fished a bit then decided to go joy ridding, see if the new plugs help our previous speed problem. after the first time we tried to get out of the hole, the motor bogged down and died,after starting her back up we noticed water just trickling out of the pee hole we never could get the boat to go unless I tapped the choke button when I was trying to give it gas, it would run well for a sec, then need another choke, eventually it would just fizzel out and die. the motor is properly trimmed, and I'm running a fuel mixture of 50:1 which has typically done us good. Back on shore I put the muffs on the motor to check it out, only to find Gearcase lub on the outside of the lowerunit, and most of it was comming out of the Teardropp shape hole on the drivers side of the lower unit near the shift linkage. I put the muffs on, start her up and the water quit flowing from the garden hose but not out of the pee hole, however there is alot of water comming out of the exhuast holes right above the hydrofiol, where the L/U bolts up. there is all lub comming out of the L/U where it meets the mainbody.<br /><br /> so in short, the motor bogs down, with load, not on land. No tale tale, and leaky l/u lub<br /><br /> are theese problem possibly related, and where should I look to find the source of the problem<br /><br /> sorry the post is so long winded<br /><br /> Thanks,<br /> Thomas

 

[boaterntexas]

Re: When will it end.. Compound probs with Merc

side note. the boat is a 17' fiberglass bass boat, we where on a river, it ran okay going down river, but comming back up the river was where it got really bad

 

[boaterntexas]

Re: When will it end.. Compound probs with Merc

I'm sorry one more thing.. The motor has a good rythm with the exception that it jerks, or stutters ever sec. or two, but it's timed in there well, is this normall, when the boat is in gear and going a low speeds, you can actually fell the motor give the boat a little shove about every 1.5 secounds.

 

[roscoe]

Re: When will it end.. Compound probs with Merc

I can feel your pain. You must be very frustrated with all the problems you have been having.<br /><br />As for the pee hole, there may just be a clog in the line. Try pushing a wire into it to dislodge anything that may be stuck in there.<br /><br />The jolt or shove, Sounds like you have a worn clutch dog in your lower unit, along with worn gears. A shift rod adjustment may help, temporarily. Replacement may be in order.<br /><br />Oil leaking, Drive shaft or shift shaft seal is shot. Lower unit could be pressure and vacume tested, but it sounds pretty obvious, and ominous. Pull the lower unit, have seals replaced, have clutch dog and gears inspected/replaced.<br /><br />As for the accelleration probem, It could be anything from a restricted fuel line, an air leak, clogged carbs???<br /><br />Personnaly, I would find a competent outboard mechanic and have him go thru and clean, adjust, or replace all problem parts. Give it a good going thru, and get it all taken care of at once.

 

[Yepblaze]

Re: When will it end.. Compound probs with Merc

It's just the compunded issues of owning a older (or even newer) unit out of warranty in need of multiple repairs.<br /><br />Sound like a compression check might be a good place to start.<br /><br />While you are at it, pull the carbs and dissassemble completely while making sure all jets are cleared of any debris.<br /><br />Put some kits (with check valves) in the fuel pumps.<br /><br />Change the lower unit and see if water is actually mixing into the oil. (milky not just aereated) Pressure/vacuum check the lower unit to pinpoint or isolate the water intrusion.<br /><br />Sometimes a poorly running motor developes so much unburned fuel mix it will appear as if oil is leaking out of the foot.

 

[Gold Bear]

Re: When will it end.. Compound probs with Merc

boaterntexas<br /><br />"after the first time we tried to get out of the hole, the motor bogged down and died"<br /><br />The fuel mixture is lean. At each carb, lightly seat the idle mixture screw, then open it up 2-1/2 to 3 turns. (Mine works best at 3 turns). Test drive the boat on the water. If the engine still boggs, open up each screw until the bog goes away. You could probably start at 2-1/2 turns then test it from there. All three screws need to open the same amount.<br /><br />Good luck,<br /><br />Gold Bear

 

[ODDD1]

Re: When will it end.. Compound probs with Merc

Tom, to answer the question, "what do I have to do to make this a reliable boat?" the only safe answer is REPLACE THE MOTOR ...dont get me wrong, this was a wonderful motor, which I'm sure has served its previous owners well..but we are talking about a 27 year old engine, which had an average service life of 12-13 years....its day is done, and even with a healthy investment in a rebuild, reliability will never be what you ask of it....

 

[bret walters]

Re: When will it end.. Compound probs with Merc

i agree wiht odd1 a new engine is the best money you will spend.

 

[mellowyellow]

Re: When will it end.. Compound probs with Merc

agree a new motor would be more reliable, but if<br />you don't have $6-10K it's not an option.<br />If I were you, I would do the following:<br />1) check compression and spark<br />(if these are good)<br />2) R/R carbs, fuel pumps & entire fuel delivery<br />system.<br />3) adjust as Gold Bear suggested<br />if you have good compression, and strong spark<br />on all 6, you should be able to get her running<br />pretty good with a little work.<br />good luck,<br />M.Y.

 

[boaterntexas]

Re: When will it end.. Compound probs with Merc

Thanks for all ya'll help<br /> Here is where I stand, I carried the boat out again, and pump the bulb, she still bogged down some but I was stilla ble to get here going well, with someone else driving and me pumping the fuel I got here up to max (5500) RPMS, and running well, but if I stopped pumping she would slow down and drop down to about 3500 or 4500 rpms. So My guess is fuel system, I did notice that sometimes the bulb wouldn't need squezzing it would allready be firm, but only for a sec. Oh-yeah I also tinkered with the Idle stop, throttle stop and spark advace screws and got it gettign up and out a little bit better but not idling well now, only at 1000 rpms. any one have any help on theese three adjustments?<br /><br /> Is there anyway to test the compression with out paying for it. I mean can I just listen to the motor, or somethign like that to deciced if there is reason for an actuall professional test, becuase I personally feel that the compression is fine, but what do I know.

 

[Hooty]

Re: When will it end.. Compound probs with Merc

Check with your NAPA Dealer. You should be able to get a compression gauge for under forty skins and then just do it yourself.<br /><br />c/6<br /><br />Hooty

 

[Solittle]

Re: When will it end.. Compound probs with Merc

Check all fuel line connections for an air leak. If that dosen't do it check fuel pump pressure.

 

[John Reynolds]

Re: When will it end.. Compound probs with Merc

I think you really need a manual. You could get one for about $20-$35.00

 

[bill cook]

Re: When will it end.. Compound probs with Merc

I agree with solittle check fuel lines. Also are you running an older steel fuel tank? might have a leak in a seam or pinhole above fuel level line,<br />bad seal around gas line connection, crack in rotted ball-pump,check these.<br /><br />plastic tank? check also that vent is working correctly, or take the cap off when your having this problem, see what happens