Hard Starting and No Idle

[CrestII]

First time posting been reading for the last couple of years. I have a force 96 75 hp outboard that is very hard starting and when it finally does it will only run at wot. When i try to bring it back to idle it dies instantly unless i open it wide open again.This started last year on the lake while we were camping. I replaced the fuel primer valve as it went bad last year.I have changed the fuel line,primer bulb,fuel pump kit installed,new plugs, new inline fuel filter,and took carb off and cleaned and blew out with air. Nothing really came out of the carb when i cleaned it.Put it back together and still same problem. I checked the compression on top two cylinders and they were ok ,cant get to the bottom one cause where it sets so low i need the attachment to reach it but the plug looks the same as the other two (oily).Any help would be appreciated it hasnt seen the water all summer.

 

[jerryjerry05]

Re: Hard Starting and No Idle

Even though you changed the hoses the Ethanol might have done some damage.The Ethanol delaminates the old hoses.Small particles go everywhere.The carb has a main jet that has a small pin hole for the idle.Make sure that isin't blocked.Then reset the air screw.Replace any old or soft hoses.J

 

[CrestII]

Re: Hard Starting and No Idle

Thanks for the reply jerry i took the main jet out when i cleaned it and it looked good i soaked it and blew it out just for good measure. I havent replaced the fuel recirculation hoses yet but i am going to. I never had this much trouble with this motor before this happened.I sunk bout 800 bucks in new plywood and vinyl flooring this spring now i wish i would have spent the money on a good mechanic.lol

 

[john from md]

Re: Hard Starting and No Idle

Check to see if the fuel bulb is getting soft when the engine shuts off. Next, try pumpin the ball periodically to see if you can keep the engine running. If this scenerio is what you are experiencing, change the three check valves in the fuel pump as they are sticking from ethenol.

John

 

[CrestII]

Re: Hard Starting and No Idle

I put a new kit in the fuel pump but dont remember three check valves. I think it had 2 that you had to punch the plastic in the center if thats what your talking about.The bulb does get soft and it wont keep the filter full of fuel.I put a clear filter on so i could see it. Sometimes i think its the fuel pump but its all new and i took it back apart to check for trash or something in it and it all looks good.

 

[john from md]

Re: Hard Starting and No Idle

I stand corrected. You have the later model engine with the different fuel pump. The ball should stay firm even when you have shut the engine down until evaporation causes fuel to dissapate.

Your problem has to be that the fuel pump is not working properly. Get a quart size glass jar and disconnect the fuel line from the carbs and put it in the jar. Pump the ball until a good volume of fuel comes out. Next, engage the starter and watch how the fuel comes out of the hose. It should be pretty much a solid stream. If it is intermittant, take the fuel pump off and make sure the holes in the vacuum and pressure ports are clear.

John

 

[CrestII]

Re: Hard Starting and No Idle

Thanks John i will try that as soon as i eat dinner and will post what i find.

 

[CrestII]

Re: Hard Starting and No Idle

Ok i pulled the hose going to the carb and no fuel flow when i crank it. So im gonna take the pump off and see what i can find out. Is there anything else i can check while i am at it?

 

[john from md]

Re: Hard Starting and No Idle

I would disconnect your fuel supply hose and do the same thing with the bulb to make sure you don't have a bad check valve in the bulb or a air leak in the line. The only other thing to make sure of is that you have the check valve diaphrams in the right direction.

John

 

[CrestII]

Re: Hard Starting and No Idle

When i crank the motor i have nothing at the pulse fitting coming off the pump is that supposed to suck or blow or do something? Also i took fuel pump off and checked it couldnt see anything wrong but still not pumping fuel at all. I squeeze the bulb fuel flows but when i crank the engine nothing comes out?

 

[john from md]

Re: Hard Starting and No Idle

The hose or the passage way in the crankcase may be clogged up. Try blowing through it or spraying carb cleaner in it. That is the implus line going to one side of the pump. Under the diaphram is a port the acts on that side. Between the two, they should be sucking an blowing so that the diaphram moves and pumps fuel.

John

 

[CrestII]

Re: Hard Starting and No Idle

Do you mean the port behind the fuel pump is clogged or the pulse fitting on the front of the pump? I blew air through the pulse hose going into the motor but when i blew it through the pulse fitting going to the pump it was stopped but i just figured that is the way it is supposed to be. This fuel pump was simple to put the kit in (or so i thought) but maybe i have done something wrong.I have a manual and i looked at it again today when i took it apart and it seemed like everything was installed correctly but still no fuel. What piston would that run off of cause the hole in the block in the back of the pump looks like its number 2 but then the pulse hose looks like it goes to number 3? Sorry John for flooding you with rambling questions im just trying to figure this thing out before its time to put it up for the winter which will be soon.

 

[john from md]

Re: Hard Starting and No Idle

Number 2 runs one side of the pump and number three runs the other. It is easy to understand when you think of each piston as a pump. When it goes up, the effect on the diaphram is vacuum, when the piston comes down, it makes pressure. One piston does a vacuum/pressure cycle for each side of the pump. That is why both passages must be clear.

Even if you put the fuel pump together correctly, with out the suck and blow of the pistons it won't work. The first thing you need to find out is if those passages are clear.

John

 

[CrestII]

Re: Hard Starting and No Idle

IM going out today to work on the boat again. I do have some good news blew the ports out you told me to and put it back together finally got my pulse line to work but still no fuel flowing to the carb when cranking. I did also finally get a compression check on number 3 cylinder its the same as the others 120 on all three. I willl see what i can find out today so far this has been the closest ive come to getting in the water all summer.If you have anything else you think i should check John i will be coming back and forth to the computer and the manual all day.lol

 

[john from md]

Re: Hard Starting and No Idle

If your impluse ports are clear and working, and you have supplied fuel to the fuel pump via the primer bulb, you should have fuel pumping out of the pump. The only thing I can think of that will not allow it to pump fuel is if the check valves are bad or the diaphram is bad.

John

 

[CrestII]

Re: Hard Starting and No Idle

I appreciate all the help you have given me John. Im gonna throw in the towel on this one i have done everything i can think of and still cant get this thing to pump fuel so im gonna have to take it to the shop. I hate to pay these guys big money for it to be something that is probablly just so simple that i could have figured it out but its better than having a 24' yard ornament. I will post what they find out.

 

[john from md]

Re: Hard Starting and No Idle

You are probably right, something small and easily overlooked. When you go to the boat shop, give them a list of the parts you replaced as it may save unnecessary costs in parts and labor.

John

 

[CrestII]

Re: Hard Starting and No Idle

busted reed valves so far.One is missing and one is broke in half .He took them out and showed them to me. $177 for parts and $112 for labor. So far thats about it. He said he done a compression test and came up with about 90 on each cylinder but I have done it 2 or 3 times and came up with 120 but we will see what the new reeds do for it.

 

[mahdix]

Re: Hard Starting and No Idle

CrestII

I am very interested to know if your boat is running for you now and what exactly you had done by the shop to fix it. I have done all of the troubleshooting that you have and nothing seems to work. My boat is doing the exact same thing and its already taken 4 of my summer weeks from me. I am no boat mechanic but would like to fix it myself and to save some money if I can. Any help is much appreciated.

Thanks

 

[CrestII]

Re: Hard Starting and No Idle

No its currently in the shop with broken reeds. John has given me alot of good advise on here and i tried everything he said just go back and see if any of it helps you. Make sure you have good compression and its pumping gas to the carb. Do you have the same moto as i do?