Cold start issues with 115 HP

Hello to all,,,I have a 1983 115 Mercury SN. 06300368 on my 24' StarCraft Pontoon that has been kicking me in the teeth,,,,! Due to some health issues, we had stored the boat for 5 years and just recently decided to get her going again. I replaced the spark plugs and put new gas in the tank and after a lot of coaxing, finally got the engine going but having sat so long, water pump also needed replacing. Then had issues with the shift cable and replaced the cable and wound up rebuilding the control box and also replacing the tilt/trim switch. All that works like brand new and now shifts so smooth,!! Now,,am fighting some cold start issues with the engine that I really need some help with. It is now VERY hard to start when cold and to the point that starter bendix spins out right before it starts. after several times like this it will finally start and will run rough for a minute then smooths out and runs great. After engine warms up it will start right up and every time after that,,!! you can't hardly get off the key quick enough and it will start and run great,!! This engine has a "solenoid" that what I'm told sprays fuel into carbs when you push key "IN" while cranking to start. I can feel a slight click in solenoid when neighbor pushes key in but I am not able to look into carb venturis to see if fuel actually being sprayed. "click" is very light and hardly noticeable unless you are standing next to engine. Top of solenoid has a knurled shaft on top that looks like an "adjustment point". It was screwed "out" about 1/4 round. I screwed it out all the way and then re-set to original setting of 1/4 round. Did not make any difference in sound or feel of solenoid or ease of engine start. Looking for some engine GURUs to give me some pointers and suggestions on how to procede. NOT really looking forward to dismantling the carbs,,but you got to do what you gotta do,,,,? A little help,,,???

When the motor is running and you push in the key , what happens ?-----The knurled shaft is for manual operation of the enricher system.--------Have you taken the starter apart for inspection ?------Slow cranking means motor will be hard to start.

Hey Racerone,,,thanks for the comeback. I appreciate the help. Yes, when I first started having these issues with cold start, I removed the starter and checked both bushings and brushes and everything was good. I went ahead and installed a new bendix thinking it was problem. Actually the starter spins very fast before and after it finally starts, it's just that the bendix "spins out" right before engine starts when cold. Now, once it does start and warms up,,,it will start VERY quickly and you can't hardly get off the key fast enough,!! I mean, engine will only spin maybe one revolution before it starts,!! I have not tried to push in key after engine starts,,,but on thinking bout that,,,,that would prove if cold start is working cause engine would maybe start missing from too much fuel,,????

I have a 1982 Mercury 150 that is hard to start when cold.will turn over several times and maybe start and run rough and when you try to gas it it will backfire through air filter.after several attempts it will start and runs strong the rest of the day till next day and same thing all over

Hey Kenbassfisherman,,, I am about to beat my brains out with this thing,,,!!! IF I can figure out why my engine is doing this ,,,,I will most certainly help you but not there yet,,,!!! I finally took the three carbs off thinking they might be gummed up due to boat sittin for such a long time. The carbs were really pretty clean inside. I sprayed carb cleaner into all the orifices and jets and then I made me a blow gun with a piece of plastic 1/16" tube to get the air pressure into those small orifices and passages. I think the carbs are CLEAN!!!!!! I DID NOT remove the jets that have some sort of thread locker as manual stated to leave em alone..I assembled and installed the carbs. The "enricher" solenoid on this engine opens when key is "pushed in" while cranking engine. When Enricher solenoid opens, some fuel flows from fuel bowl of TOP carb into side of solenoid, then fuel flows to a 3 way "TEE" that is threaded into cylinder head for #3&4 cylinders next to middle carb. The fuel splits there and flows to a fitting on cylinder head for #1&2 cylinders and bottom cylinder head for #5&6 cylinders to "prime" the 6 cylinders for initial start. That's the way it is SUPPOSSED to work,,, but it sure ain't working,,,!!! Sonebody tells me that the knurled bolt at top of enricher solenoid is for manual "choke". Is this knurled bolt supposed to be closed or OPENED in normal operation???? Can somebody help us a little???

The way that deal works (and VERY well if it's set up properly) is for gas to flow into the motor when you hit the 'choke'. Now, if the bulb hasn't been pumped up enough there will not be enough gas available; also (and this is commonly misunderstood) if the motor does start on the first attempt you have RE-pump up the bulb again.

Here's what I'd do in your case: Pull all the hoses off the block and (being fire safety careful) pretend you are going through the start up procedure--use a helper. You should see gas gush out of every one of those hoses. If not, find out why not and correct it.

Jeff

There is no " cylinder head " on that motor !!----------The key is the be pushed in and held in while cranking the motor over.----Did you do an ohm reading on the armature when the starter was apart ?

Hey Fastjeff,,,thanks for your help. The engine does try to start at first attempt, and soon as that happens,,,the starter bendix spins out. but I was not aware you had to re-pump bulb every time it tries to start, and I shall address that this morning. On the "enricher" solenoid , , does the spring loaded knurled knob at the top of solenoid have to be screwed down all the way or opened up all the way? What is the setting supposed to be? I need to have this info before I can proceed with other trouble shooting, don't I ?? I am going to do as you suggest on the fuel lines to and from the enricher solenoid. I was going to do just that and measure HOW MUCH fuel came out of the enricher solenoid, but when I pushed in on the key, it blew the fuse in the starter solenoid circuit,,,?? Do you HAVE to be cranking on engine when you push key in?? I am kinda suspecting the dang enricher solenoid of not letting enough fuel to engine but,,,,? Hey Racerone,,,you might have answered one of my questions to FastJeff,, on whether you HAVE to be cranking engine when you push key in to prime. My bad on my terminology re: cylinder head,,,maybe I should have referred to the location the three fittings where the fuel from enricher solenoid goes into the block,,,? Also, I am going to try a "lighter" spring above the starter bendix to see if that will address the "spinning out" situation. I DID NOT ohm the armature or the fields on the starter. The starter has always spun the engine more than enough to start and when it does finally start and runs for a minute or two,,,you just cannot get off the key fast enough before it is running! I mean engine will not turn over a complete revolution before it is running,,,,,but like Kenbassfisherman,,,you have to go thru this mean-ness all over again the next day. Can somebody PLEASE tell me how to start a new paragraph ,,,????

A lighter spring will not help !

,,,,,,OK,,,,, a lighter spring will NOT help ,,and I can prove it,,,!!!!BTDT OK,,,an update on the 115. I removed all the hoses from the fitting at the top carb, thru the enricher and all the way to where each fitting goes into the block. I verified each hose was clear except for the hose from the enricher and thru the "T" at the middle carb. I could plug both running sides of the"T" and was hard to blow thru the "T" and into the block. I removed both the hose and the "T" but did not find anything but think whatever was in there must of fell out as, after I re-installed the "T",,I could now blow thru it fine. Put everything together, pumped up primer bulb, and the dang thing STILL would not start,,,!!!! I got some starter fluid and shot some into top and middle carb,,,and it fired right up,! UREKA,,,!!! Let it run bout 10 minutes while I adjusted the low speed jets,,,and NOW,,, I noticed the engine RPM does not come down to idle speed very well as it used to. Tried several times and idle would stay high for bout 1-2 mins. I had to pull on throttle arm to bring engine RPM's down. I throttled up several times and , engine would take too long to idle down. I noticed the top half of the round plastic housing that has a wound spring inside was loose and would not close around the spring inside. I am to the point of trying to machine a "PULLER" to remove the flywheel. You CANNOT remove the bolt that holds the two halves of the round idle return spring housing unless you remove the flywheel,!!! JEEEEZE,,,!!!!! There is not a Mercury or even an outboard dealer within 300 miles so no chance of borrowing a puller from them. Can anybody that has one of these " Flywheel Pullers" tell me what the thread pitch is on the big size???? I could not get my thread gauge very well on the inside threads of the flywheel but looks like they MIGHT be 24 TPI... Can somebody Please verify this for me?? Many thanks Joe r

I use a two jaw puller with two grade 8 bolts. Never had one refuse to come off.

Jeff

Hey Jeff,,,looked at mine again and there are 8 bolts in a small bolt circle right next to the flywheel bolt, then there are 8 other bolts around the outer periphery of the flywheel itself next to ring gear. Are these the bolts you refer to? NEWS FLASH,,,!!!! My toolie-wak is the blackest,,,just received an email from an Ebayer that the thread is in fact 16 TPI so went and measured with thread gauge again,,,,and it sure is 16 TPI,,!! Guess I'm goin to have to get new glasses,,,!! Now to fire up my lathe and thread the big end of the puller.

I don't talk to people with a lathe!

Jeff (AKA Mr. Jealous)

Ha,!! Ha,,!! Ha,,!! I was the same way, Jeff. I always envied those that had a lathe cause I believe they are the Ultimate tool a DIY can have in your shop/garage. Much more if the lathe has a mill with it ( which mine don't) but I hope to find a small mill one of these days that I can afford. With as many "projects" as I have going on, I prolly use the lathe once or twice a week and sometimes more often. I finished up making the flywheel puller last night, just need to tap the threads for the "pusher" bolt in the center that will "pull" the flywheel off the crankshaft. The 1 1/2" 16 TPI threads on the big end fit the flywheel like a glove,!!! You know,,,little by little, I'm goin to get all these issues addressed and get this boat SOLD,,!! This is a dang good example of things deteriating (sp) when not in use,,,but somebody is goin to get em a dang good boat, what with me doin all this work to it. Thanks for all your continuing assistance, Guy.

OK,,,,I used the "puller" I machined on my trusty lathe,,heh,,heh,,,heh,and screwed down on the tool and Popped that flywheel right off,,!! YES,, but NOW,,I got another problemo,,,,Whenever I would throttle up and back to neutral,,the engine RPM did not come back to normal idle but would stay at maybe a 1/3 idle until I would pull on the throttle arm to get it to idle RPM. I took the top cover off what appears to be the spring loaded idle return assembly and The spring inside was all bent up out of shape. I tried to re-wind the spring but it appears to have lost it's tensile strength, and will not remain round. I have no clue if you are supposed to wind the top one time or two,,,?? One time doesn't seem to be enough and two times seems to be too much,,,??? anybody here have a manual that explains the procedure for installing this assembly??? I looked at a couple of Mercury parts places for a new spring,, but they do not even list these parts,!!PLEASE Don't tell me these are some more NLA,,,????

GOOD MORNING,,,,,,I wish for some help,,,,please,????? I located what looks like the advance return spring on ebay,,, mercury PN 24-55162. I have not been able to locate a part number book to see if this spring will work on my 115 HP. mine is messed up and will not return the engine RPM's to idle. Can somebody PLEASE do a cross reference and see if zi can use this spring? many thanks Joe r

Hey Kincrwbr1,,, many thanks for your quick response, I do appreciate your takin time to help me. I went to that link and it is a little different than the one on my engine but the spring looks to be the same,,? On my 115, the "throttle/advance" mechanism lays flat and the 1/4" bolt holding the two halves together is in a vertical position, hense the assembly is in a "flat" orientation,,,?? ( Don't know if I said that right,) The 1/4" bolt in the link is in a horizontal position,,?? I think both systems work the same way. Yes, I had disconnected the throttle cable from the throttle arm, so I could work the throttle back and forth and that is what led me to the return spring not returning the advance AND the engine RPM back down to idle. The spring is NOT broken but you can bend it any way and it will NOT return to it's coil shape, although when I'm trying to "reverse wind" the cap on top of the spring, the spring will become twisted inside the assembly and not let you close the two halves together. Is the correct procedure to "reverse wind" the spring ONE revolution or two???? I hope I am explaining this right cause I don't want you to give up on me. Ha, Ha, Joe r

UUUmmmmmm which one is the trigger plate,,,??? YES,, I would say the spring is sprung. Goin to try to post some pics. Wish me luck,!!

Hey Kincrwbr1,,,I'm back,,!! I found a complete advance assy with the spring for a 140 Merc on Ebay. It is exactly the same as mine with same casting numbers and all. The other spring I ordered (PN 24-55162) was way too big and bout three times too big around,!! I received the advance assy today and have installed on the 115 but the trigger is now keeping the throttle from returning all the way down to idle.. I did as you said, and disconnected the link to the trigger and the trigger is hanging up a little at it's lowest point. I cannot see "WHAT" is hanging it up, tho. There are 4 small allen head screws in an uneven pattern that hold the trigger down. Not having ever taken one of these apart, I want to make sure I'm not going to screw something up or break something. Any ideas what mat be causing the hang-up?

The flywheel is already off and in moving the advance link rod back and forth, it has a slight tight spot right before it comes to the idle position. Are you calling the "TRIGGER" as being the somewhat round gray laminated piece that moves back and forth inside the big coil looking thing? This gray painted "trigger" has 4 allen head screws holding it down. These 4 allen head screws are not spaced evenly around the coil which is prolly how the trigger is correctly orientated,,,??? I do not have a manual and was hoping somebody would chime in and post something,,,, You got one?

Hey Kincrwbr1,, that Ebay link you sent is the part (trigger) that has the tight spot. I will take a closer look and see what is binding under there. All this area is exceptionally clean so don't think it is old grease or ,,,?? I've got my wife of 46 years in the hospital since Sunday with a stubborn UTI so, won't be able to spend some time with this til I get her home, and I do appreciate your taking time in helping me resolve this thing. That's the pits that Mercury has most of the parts for the older engines as NLA but I'm even gladder that the parts are available although as used ones. The advance assembly I got off Ebay was in really good shape with very little wear on the plastic wearing surfaces, so guess all's well that ends well, Huh? The thing I am concerned with is that the used part was for a 140 HP and timing settings "might" be a tad different than my 115,,,,?? although the 2 screw settings look to be pretty close as to number of threads showing on the 2 adjustment screws.

The trgger is the inner piece around the crankshaft that is connected to the throttle /advance arm on the port side, and it needs to be free some times it gets dirty in there and moves stiff spray some wd 40 in there and move it until it frees up ....those inline motors are notorious for being hard to start as it takes alot of fuel in the crankcase to get a fuel charge, I have found it helps to have someone squeeze the squeeze bulb while im pushing in on the choke and the squeeze bulb will force more fuel through the primer hoses than normal fuel pump pressure can making it start easier hope this helps you.

That's her. I've seen lots of binding when you work the throttle that seems to work itself out with time an exercise. Perhaps some grease on the trigger coil would help?

Jeff

PS: The coiled spring in the throttle am can be a nightmare to get right.

Hey Guys,,,I have not done anything to the 115 since over a week ago. My wife of 47 years developed a severe Urinary Tract Infection that progressed to the point of a highly resitant Bacteria growing in her blood stream!!!! Then her blood sugar went ballistic all the way to 713,,,!!! We almost lost her a couple of times before they transferred her to a special ward for infectious diseases at University Hospital in Lubbock, Tx. Talk about a close one,,!! We finally got her home late last night with a PICC tube in her arm for home injection of the antibiotics that were used to finally get a handle on the bacteria. being away from home for over a week has left me with several things to take care of,,,but am chomping at the bit to get that 115 back into running shape. Gonna give it the WD40 treatment first before I remove any more parts off the engine,,,, Many thanks for the help and suggestions you guys have volunteered and I feel we are getting close now,,,

Good luck with both problems.

Jeff

OK,,,took the trigger out and problem was some grease that had dried and hardened on the moving surfaces. cleaned all the old grease and put a light coat of moly lube on both surfaces and she works smooth as ,,,,well SMOOTH,,,! Put everything together and,,,,and ,,,,it TRIES to start but still have the issue where the starter spins out right when it tries to start. Got my spark plug testor and checked all spark plugs to verify all have fire and all OK. BUT it will NOT start... Even tried a little starter fluid and it almost started but no dice. The bottom carb started flooding over so I stopped and will pull that carb to check trash or ??under needle/ seat.. I NEED SOME HELP.!!!!!!!

First of all, you got to make the carb(S) operate properly. All three need to be pulled and cleaned, and the fuel pump diaphragm changed as well. (Ethanol eats 'em up, resulting in a flooded condition at those cylinders.)

Do that--and change the gas lines if they are stiff--then get back to us.

Jeff

Hey Jeff,,,thanks for the comeback, I appreciate the help. That was going to be my next question to the group about the fuel pump. Do you know a supplier that carries a rebuild kit for these pumps? PLEASE tell me how to start a new paragraph. hitting "enter" will not do it but I see your posts do have separate paragraphs. Anyway, I had already taken all three carbs and cleaned em thinking there might be some residue from engine setting so long, but they were actually very clean inside. What I didn't do was, remove the screws (jets?) that looked to be factory sealed with thread locker,,,? I checked float levels according to an online manual so the btm carb that is leaking must of got some trash under needle,,,????

THIS site sells everything you need for that motor (and damn reasonably).

Jeff