Problem starting 75HP

[jwr_20]

Hello all.<br /><br />I am having problems starting my 75. It seems as though the motor isn't getting any gas when cranking it over whether or not the choke is enabled. The only way I am able to start the motor is by spraying some fuel/oil mix directly into the carbs while cranking over, it starts very easily then, and idles very smoothly. It also runs great at full throttle. It does tend to stall sometimes when shifting into gear. After running the motor and shutting it off, it will start immediately again with no trouble, but if it sits for more than a few seconds it needs to be sprayed to start it again. I am using fresh fuel, and my fuel line from the tank to the engine is brand new as well. I can prime the fuel pump and carbs with the squeeze ball until the ball is firm. I am using brand new spark plugs as well, and they are not fouled after cranking. I have a Seloc manual, and as far as I can tell it could be the fuel pump. Any help on where I should start would be greatly appreciated.<br /><br />Thanks.

 

[jimalsk]

Re: Problem starting 75HP

Start with the fuel pump.

 

[Keith Buchanan]

Re: Problem starting 75HP

$20 should get you a fuel pump kit, don't go for the cheaper insist on an original Merc kit which comprises of a couple of diaphrqams, gaskets, springs etc and with a few basic tools and an hour you should have the job done, by the way if you cant get original Merc nylon ratchet ties (which I believe they sell by the 100), use normal ones from your auto store but wrap them around the fuel lines twice or they pinch and let air in or fuel out.<br /><br />Best of luck and keep posting.<br /><br />Regards Keith B..

 

[jwr_20]

Re: Problem starting 75HP

OK, so I picked up the fuel pump kit, and replaced all the parts, and reinstalled the pump according to the specs. It did seem to help a bit. I almost got it started without using the spray bottle, but I ended up having to, and that was after sitting since Saturday afternoon. It is still hard to start unless it has just been running. I am thinking about running some carb cleaner through it, the gasoline additive kind to see if that helps any. I may decide also to rebuild the barbs, but I am exploring cheaper alternatives first. The boating season is pretty well finished here, and if I am going to rebuild the carbs then I will wait until March sometime.<br /><br />Any other ideas would be great, and thanks a lot for the help this far, I really appreciate it!<br /><br />JR

 

[Barnacle_Bill]

Re: Problem starting 75HP

Check your fuel enrichner. With the key on, push in on it and you should hear the enrichner click. There should be a troubleshooting procedure for it in your manual.

 

[jimalsk]

Re: Problem starting 75HP

I had the same problem with my 1985 75hp. Give this a try.First on the face of the carbs on the port side there is an adjustment screw, fuel/mixture, Turn it till it gently seats,now turn it 2 1/2 turns out,counterclock wise. Do this to the other carb. Now on the side of the remote control there is a button, push it in and hold it moveing the throttle lever forward this puts it in throttle only not in gear,turn the key to on, push the key in, you should here a click,that is the fuel enrichner valve engageing. Hold the key in while you turn it to start. After it starts warm it up. When it warms up drop your lever to nuetral. Turn the adjustment screw clock wise,slowly, til the motor starts to sputter, back it back out 1/2 turn. Now do the same to the other carb. Go back to the first carb and turn the adjustment screw clock wise. When it starts to puck back it out a 1/2 turn. Same with the other carb. Once it is running smoothly back out the screw on both carbs another 1/4 turn. Shut it off and let it set for a few minutes then hit the key. If mine sits for an hour or so I have to put it in throttle only and hit the key and I'm off. I am assuming your set up is the same as mine. You did not state the year of your motor. Give it a shot it worked for me.

 

[jwr_20]

Re: Problem starting 75HP

I assume IBNFSHN, you are referring to the electric choke, it is working properly, I have also tried the manual choke as well. Sounds good Alaska River Runner. I'll give that a try and get back to you. The motor is something like a 1984 or 1985. I got it from a friend last week, he mentioned it was hard to start as well.<br /><br />Thanks again!

 

[jwr_20]

Re: Problem starting 75HP

I have adjusted the idle mix screws, and it seems to have improved! I no longer have to spray gas into the carbs to start it. It is still a little difficult to start after sitting for awhile, but I think I'll try adjusting the idle mix a little more. I am still getting used to the tricks of that specific motor. I am still open to ideas if anyone has anything to add. <br /><br />Thanks A LOT for all the help from everyone!

 

[jimalsk]

Re: Problem starting 75HP

I'm glad to hear that you don't have to spray fuel into the carbs to start. As I mentioned before I have to engage the shifter into throttle only after it has been sitting for a while. It has now become a habit to do that. Becarefull not to lean out those idle/mixture screws. It's better to run a little fat than lean. I recieved my 75 the same way, it was given to me cuase no one could start it. My gain there loss.