78 115 evinrude still having cranking "issues"

[gonefishin485]

so ive done just about everything i cant think to do to this motor

ive rebuilt the fuel pump
cleaned the carbs (spotless)
decarbed the motor
replaced fuel line, bulb, tank and fittings
and still ive got problems

heres my two situations

from a cold start its almost impossible to crank
i use to have to spray gas in the carbs throats to get it to crank, but now, after a while it will crank on its own.
it still takes a good while to crank and will drain a battery before it does.
here is my starting procedure:
pump primer bulb untill firm
lift fast idle lever all the way up
engage electric choke
spin motor and hope for the best

during this process, it will pop over a few times, but never fully crank and run. untill im just about fed up then it will fire up, run like its bogged down, then rev way up, i let it warm up for a minute then slowly lower the fast idle lever. i will let it run to recharge the battery, after a few minutes i will shut it off, and it will recrank in less than one full rotation of the motor.

if i shut it down and leave it for any length of time, the primer bulb will go soft, and i have to resart above process all over again.

whats the deal? ive never had this much problems with a motor before, ive got a 75 johnson 70 and even after sitting up for months, i can put fresh gas and a hot battery on it, and all i have to do is choke it, and itll fire right up, even without using the fast idle lever. i want this 115 to run as good as this 70.

what could it be? my neighbor said new spark plugs, ill try it but somehow ive got a feeling it wont make much difference. come on some one out there has to have worked on a stubborn ol motor like this before, help a fellow boater out please!

 

[5150abf]

Re: 78 115 evinrude still having cranking "issues"

Are you holding the key in?

The choke is only engaged if the key is pushed in and comes off as soon as you release it.

Not implying you are stupid but some people don't know that.

And I usually only went half or a little less on the fast idle lever, you may be advancing the timing too much so try a different setting on that, I know mine is kinda particular on the placement of the lever, alittle too much or too little and it won't go.

The bulb will only be hard until you start the engine then the pump draws fuel and releaves the pressure so you should be able to get a squeeze or to on it, the pump would have to be in the tank to keep the bulb hard.

Good luck and let us know if any of that helps, oh and change the plugs, they do make a huge difference and you can't look at a plug and tell its bad.

 

[emdsapmgr]

Re: 78 115 evinrude still having cranking "issues"

Significantly advanced timing will make it very hard to turn over. Check to see that the timer base link arm is connected. If it comes loose on one end, and the timing advances, it will seem like the engine is slow to crank and appear to have too much compression. Recheck your sync and link and even check the idle timing with a timing light.

 

[crb478]

Re: 78 115 evinrude still having cranking "issues"

Are your choke plates closing all the way? Also are you battery cables in good shape? The choke needs to close fully and the starter needs to spin the motor at 300 rpm. If both of these things do not happen it will be hard to start when it is cold.

 

[gonefishin485]

Re: 78 115 evinrude still having cranking "issues"

advice well taken,
5150abf: not to be rude, i own another boat with a johnson outboard, and have owned many different outboards, everything from mariner, to mercury, and even owned a chrysler, im familiar with the choking system and the high idle, however, the older evinrudes and johnsons (pre 80s) the choke was not on the key, it was a small toggle switch under the key that had to be lifted to engage the choke, which i was doing, but i know you were just trying to help, thank you for the advice

emdsapmgr: all my linkages are hooked up and functioning properly, i did adjust my link and sink so my throttle butterflies are closed nice and tight at idle and not touching the throttle cam at idle, unfortunately i dont have a timing light, and really wouldnt know how to check the timing on an outboard, would like some more info on that if you dont mind

crb478: the choke plates were closing, as to how tight i cannot verify, battery cables are good, battery is a strong marine cranking battery, the battery out of my V8 truck damn near rings the starter off, so its spinning plenty fast enough, how ever.......

i did call two outboard repair shops, both said make sure my choke butterflies were good and tight, so tomorrow i will try it and give a report

 

[Mike2076]

Re: 78 115 evinrude still having cranking "issues"

Hello, Have you checked the compression cold?If you have low comp.the more you turn it over the warmer the piston and rings get they expand and make higher compression and it will start easier.i have owned and worked on these engines and they are about bullet proof.All the things you have done to this engine she should run like new,if you have good comp.i have had issues similer with a pin hole in the tanks pickup.good luck

 

[Mike2076]

Re: 78 115 evinrude still having cranking "issues"

I had a buddy that had a similar problem with about the same engine on a boat i sold him the boat would start good on a good hot battery at home but when he would get to the river in the water for some reason with the back pressure on the exaust i wouldnt start.I remember going thru what you are going thru trying to figure it out and it turned out to be the charge coil was bad under the flywheel.my manual says that charging system put out about 300 ac volts and the power pack converts it to dc voltage so be careful what wires you grab while its running!! the coil being bad was causing the power pack to make the hard starting.i even replaced the power pack and it still done it until i found the bad coil after i replaced the charge coil she would start like your 70hp.good luck

 

[tashasdaddy]

Re: 78 115 evinrude still having cranking "issues"

what are your compression #'s? if mine does not start the 1 or 2nd try i always repump the bulb, as the fuel pump has taken the pressure of. if using the aftermarket bulb, point the arrow to the sky, when pumping. they have a horrible check valve in them. motors that start well on muffs, do not have any back pressure on the exhaust. so you have to set your idle speed higher on muffs, so it will start and run in the water. once started in the water, the idle speed needs to be fine tuned to 600-750 in gear.

 

[emdsapmgr]

Re: 78 115 evinrude still having cranking "issues"

Check the idle timing on #1. The timing marks are on the flywheel. It should be 0-3 degrees BTDC on a 115/140. This is when the idle lever is up on the control box. It will have less timing at idle when the lever is down (normal idle). If you have any timing above this, then it could contribute to show cranking speeds and hard starting. This is an unlikely scenario, but worth a check. I would disconnect the starter pos lead and try jumping the starter direct from the battery with jumper cables. Sometimes weak solenoids (even bad key switches) can affect cranking speeds.