1981 Evinrude 115hp multipe problem

[jtmurrow]

I just bought this boat thursday, put it in the water Saturday. The engine idles rough and would not go into gear without first having the cold start lever up to get rpm up. once in gear it will run fine (I still dont think its running like it should) but it will push the boat rather well. Once back at idle, it will idle for about 30 seconds and then die, and we start the whole process over again. We ran it for about 2 hours, kids had fun on the tube, we stopped for a snack, and the boat would not start back up....we had to get a tow to the dock..not a fun ending to the first day out on the boat.. Anyway, i hope this all makes sense to someone out there who can possibly give me some help. My plan as of now is to, check compression, and replace the spark plugs, and maybe look into carb rebuilds.. please let me kow if i am on the right track with this. thanks

 

[mikesea]

Re: 1981 Evinrude 115hp multipe problem

Yep,first step is ,check the spark and compression.then,fuel.Cheack all filters,if you dont have one already,install a water /seperator,it looks like an automotive oil filter.You should check it periodically for water and debris.If you have a built in tank,they do over time have the symptom of water build up.Especially with the new ethonol based fuels.You might also change any fuel lines from the tank to insure thay are ethonol(alcohol)resistant.Did you squeeze the ball til it was good and hard when the no start symptom happened

 

[jtmurrow]

Re: 1981 Evinrude 115hp multipe problem

Yes, bulb was hard, i think i may have flooded it, but i still want to look into the other things, i think this motor should run a whole lot better than it did. it has a built in tank, how do i empty/drain that?

 

[gspointer]

Re: 1981 Evinrude 115hp multipe problem

Yes, bulb was hard, i think i may have flooded it, but i still want to look into the other things, i think this motor should run a whole lot better than it did. it has a built in tank, how do i empty/drain that?

I used a pump to drain my tank.

 

[jtmurrow]

Re: 1981 Evinrude 115hp multipe problem

OK, i checked compression, all 4 cylinders were between 110 and 119, i think that is pretty good, went ahead and replaced all spark plugs, it only helped a small amount. I beleive i may have a fuel pump isse, reading the manual it says it could casue all the same problems, low rpm sputter, rough idle and shutting but runs fine at higher rpm's..anyone have any ideas on this? also looking at puttin in some carb cleaner and something to dry theater out of the tank just incase there is any....

 

[Sixmark]

Re: 1981 Evinrude 115hp multipe problem

Using carb cleaner to clean the fuel tank is one thing, but I don't recommend using it on the carbs,

my general rule is that if the problem happens at idle .....look to fuel/carb issues

if it happens at high rpm look to ignition......now this is not always the case but seem to fit the majority.

Being that you just bought it and don't know the history of the motor, start at the fuel tank and work your way towards the motor.

Make sure the tank, pickup, line, and filter are clean, make sure that any vents are free of debris and OPEN when running the motor.

If you have done all of this then check your fuel pump for proper operation, make sure that any gaskets are present and in good condition.

next it might be time to pull the carbs and clean them properly, while you have them apart be sure to inspect them carefully, if you find anything that is questionable then replace it.

All of the procedures for the items listed above can be found in the FAQ/Top Secret section of the forum.

Before progressing to ignition related items it's best to make sure you have the following:

A multimeter
Spark tester
a set of jumper wires with alligator clips
an extra person to operate the key while you are performing tests

 

[jhcreech]

Re: 1981 Evinrude 115hp multipe problem

does the motor make a popping noise at idle and does around the lower cowel is wet with raw fuel, in other words can you rub your finger anywhere on the block mostly on the side intake covers and area under the carbs and near the crankshaft area and get it wet with an oily residue, if so your problem could be a lean condition causing to much air to getting into motor not enough fuel causing bad idle and at WOT it may seem fine, what you will need to do is to reseal the powerhead crankcase halfs, intake side covers (4) the intake manifold, carb to manifold gaskets and replace the upper and lower crank seals, if this is not the problem check also that the reed valves not blowing fuel back through the carbs, the lean condition is a typical problem with the all 2 stroke omc products, don't know how much u know about 2 strokes but the crankcase pressure is just as important as combustion chamber compression if you don't have either the motor will never run right and that goes for ALL 2 stroke motors, i currently have a 1986 90 hp evinrude with the very same problem, good luck i hope this helps you...

 

[jtmurrow]

Re: 1981 Evinrude 115hp multipe problem

Thanks for all the help, i ordered a new fuel pump and will start with the fuel system, the only concern i have about the block/engine is that at idle speed, it hickups or coughs and puffs out some bluish smoke from around/behind the starter. I plan on cleaning the carbs, from what i hear there is a good spray foam carb cleaner out there that works well, also i am going to put some water cleaner stuff in the tank to dry out the water. Anyone know of these products and if they work? names would be good also. thanks

 

[Sixmark]

Re: 1981 Evinrude 115hp multipe problem

Using a spray carb cleaner to clean out the carbs only cleans the parts you can see, your best bet is to actually remove them and take them apart and clean them.

If you have a removable fuel tank then just drain it and pour some isopropyl alcohol in it, that will help dry it out. DO NOT RUN THE MOTOR with the isopropyl, wait until it evaporates or you pour out the excess.

If you are getting puffs of smoke coming out from back by the starter I strongly recommend doing a compression test first.

The first steps to working on any outboard that you don't have a history on are:

Test Compression
Check Spark/Ignition
Check fuel delivery

If you skip over the basics, it will be harder to solve the problem later.

 

[jtmurrow]

Re: 1981 Evinrude 115hp multipe problem

OK, i replaced the fuel pump, no help. I swapped to a clean fuel tank, no help either. It still has a miss/hiccup at idle. I guess my next step will be to rebuild the carbs.......any other ideas out there.

I think the smoke comes from behind the fuel pump when it hiccups.

 

[emdsapmgr]

Re: 1981 Evinrude 115hp multipe problem

It is common to have idle miss issues. Commonly called a "lean sneeze," the engine may be running lean at idle. This is an occasional miss at idle. It's actually a carb problem. The small idle passages in the carb can fill up with dried fuel if not properly winterized, or if stored for a long period of time. This restriction/debris in the carbs will cause a lean condition and the "sneeze." The only way to remove this blockage is to completely disassemble the carbs and blow some aerosol carb cleaner through the passages in the upper carb bodies and reassemble. A low idle can also cause issues. The engine should idle between 650 and 750 rpm when in gear, floating normally in the lake. Your compression is fine.

 

[jtmurrow]

Re: 1981 Evinrude 115hp multipe problem

Thanks, I am getting a carb rebuild kit now. Once rebuilt/cleaned do i have to resync/link ? i have heard that a few times, not to sure of it. Also is there any kind of carb adjustments that need to be done after the rebuild.

 

[jhcreech]

Re: 1981 Evinrude 115hp multipe problem

the hiccup you got is what we call a lean pop and u said u had smoke coming from behind starter, that is a smoking gun that the block is not sealed properly, carb rebuilds and fuel pumps wont fix your problem...

 

[jhcreech]

Re: 1981 Evinrude 115hp multipe problem

look around the 4 bypass covers and the crankcase seam where the 2 halfs come together, watch these areas when it pops, you can see air coming not if not sealed, alot people do the same thing, fuel pump, carbs, ignition then check for lean condition, don't throw parts atit, know whats wrong i am trying to help you unless u can afford to throw parts at it...

 

[mamm7215]

Re: 1981 Evinrude 115hp multipe problem

I just solved this with my '81 90hp. My miss was caused by the butterflies not closing all the way. After re-syncing all was well, but it's a fine line. It doesn't take much with the carbs to be off to start sneezing/missing.

 

[jtmurrow]

Re: 1981 Evinrude 115hp multipe problem

I have the carbs soaking know. Thanks for the input on the case seams, if this doesnt work i will check that next. Any idea how to sync these carbs? i have been reling heavely on this forum and my book to ge tthe answers and so far everyone has been great help. PLease keep it coming till i get this fixed and i will pass on the good favors.

 

[Sixmark]

Re: 1981 Evinrude 115hp multipe problem

look around the 4 bypass covers and the crankcase seam where the 2 halfs come together, watch these areas when it pops, you can see air coming not if not sealed, alot people do the same thing, fuel pump, carbs, ignition then check for lean condition, don't throw parts atit, know whats wrong i am trying to help you unless u can afford to throw parts at it...

from what I can see he isn't just throwing parts at it, he is doing procedures that would be required anyhow, and along the way there is a good chance he will find the problem, a pop does not always mean an improperly sealed case. he could pull the motor apart and reseal it and install dirty carbs on it and still have a pop.

 

[Drum Luck]

Re: 1981 Evinrude 115hp multipe problem

I would bet anything that the problem is the crankcase leaking. I just went through all this with my 84 140. Same procedures as this fuel pump, carb rebuilds (on spotlessly clean carbs!),ignition tests galore! Finally broke down and tore it apart cleaned every joint and gasket surface. New gaskets and seals on everything sealed the block halves with 3M 847 even sealed all the bolts with sealant! Finally she ran perfect! Better than it ever had since I owned it! Seal the motor up you won't regret it.

 

[Sixmark]

Re: 1981 Evinrude 115hp multipe problem

Yes why not tell him to tear his motor completely apart, I can see why everyone would want to dismantle everything before testing the easy access stuff, that would be the only sensible thing to do........I'm thinking ....NO!

If you thought you had a bad spark plug, would you take the head off to check it?

Taking shortcuts and just jumping to a cure just bypasses all of the other potential causes foe the issue.

 

[jtmurrow]

Re: 1981 Evinrude 115hp multipe problem

Thanks for all the help and ideas, i do really appricate them. However i am taking this one step at a time. starting with the most probable, quickest and cheapest to fix and then moving to the more difficult, more expensive, more indepth items. Believe me, i am taking all inputs into consideration as i go through this. i want the this running like a new engine and i will eventually get there, one step at a time.

Thanks again everyone.