1988 force 85HP running issue

[nonninator]

Re: 1988 force 85HP running issue

I would also just do an all around carb tune -up...sync, air/fuel, idle etc..Can't hurt.

 

[cjac2879]

Re: 1988 force 85HP running issue

ok.. so today we took the boat out for our second voyage... We had her running great with the new plugs on the driveway with the earmuffs on... It idled good, high and low... Even ran in gear high and low rpm's... Bring it to the lake today, she starts right up.. Went through the no-wake zone at 3.5-4.5 MPH and everything was going great.. Went to give it little more throttle, and she bogged right down and stalled... Started her back up, put her in gear got back to 4mph and gave full throttle and she stalled... did this 6-8 times switching from trying full throttle to easing it up little by little... then she wouldnt start back up again....

Had to row some ways and get towed back to the launch again... thankfully people are friendly enough to go out of their way to tow us back

I dont know the RPM since there is not a tach on the boat, and the MPH were taken off a GPS

 

[john from md]

Re: 1988 force 85HP running issue

Did it start with no problem after it shutdown? If so, it maybe the check valves in the fuel pump sticking. The way to verify this is to check the bulb when the engine shuts off. If it is soft, that is one of the symptoms. The next is to try to pump the bulb as you are advancing the throttle from idle. If the engine keeps running by pumping the bulb periodically, the problem is the three check valves have swelled due to the alcohol in the gasoline.

They only cost five dollars each from most internet parts sites.

 

[cjac2879]

Re: 1988 force 85HP running issue

Did it start with no problem after it shutdown? If so, it maybe the check valves in the fuel pump sticking. The way to verify this is to check the bulb when the engine shuts off. If it is soft, that is one of the symptoms. The next is to try to pump the bulb as you are advancing the throttle from idle. If the engine keeps running by pumping the bulb periodically, the problem is the three check valves have swelled due to the alcohol in the gasoline.

They only cost five dollars each from most internet parts sites.

It did start right back up the first 6 times or so.. then it just wouldnt start anymore... During one of the stalls, when it wouldnt start again, I did check the bulb and it was still hard, but I never checkd the bulb while advancing the throttle.

How hard are the check valves to replace? I dont know much about outboards and have never worked on one, but am very handy and have done numerous auto jobs.. Is it something that is really involved??

 

[john from md]

Re: 1988 force 85HP running issue

One check valve is held in with two phillips screws and the other two are pressed in. One of the pressed in can be drifted out from the opposite side and the other is in a blind hole. I made a L shaped tool to pull the blind check valve out.

To reinstall, you just lube them with some oil and drift in with a socket that rests on the outer edge of the check valve. If you ever installed bearings in a automobile wheel, the checkvalves get drifted in the same as the bearings do.

John

 

[cjac2879]

Re: 1988 force 85HP running issue

Thanks.. Do you happen to have a picture of where these are located on the motor, or know where I could find an illustration?

This help is very very much appreciated.

Guess I need to get around to ordering a repair manual

 

[john from md]

Re: 1988 force 85HP running issue

You need to order a Clymer Force Outboard Shop Manual.

The fuel pump is on the right side of the engine at about the middle. It has six slotted head screws holding the pump housing on and several hoses going to and from. This housing sits on top of the fuel pump diaphram so it is a good time to order a diaphram and gasket and install them also. They only cost about three bucks each.

John

 

[cjac2879]

Re: 1988 force 85HP running issue

Ok thanks jon...
1 more thing that happened that might give more clues.. When we were going at about 4.5MPH and tried to go faster, the engine would start to bog down.. As soon as we felt that we would try to bring the throttle back, and it would still just stall out.. As soon as it started to stall there was nothing we could do to stop it... Not sure if that helps

I think we are just going to buy a whole new fuel pump and eliminate that out of the equation, since I think the check valves may be out of our league... We are also going to add an inline filter prior to the pump, and possibly adding the water/fuel seperator.. Just not sure if we can fit that into the budget.

 

[cjac2879]

Re: 1988 force 85HP running issue

1 other question.. possibly unrelated.

On my motor My model number is 856X8B.. When I am looking for parts the only model number I can find is HO856X88B... I am assuming it is the same number. Am I correct?

And when I go on Mercury's website to look up parts it asks for a serial number. When I type in the serial number 2395.. it comes up invalid.. I was told to add 4 zeros in front of it, and it comes up a 40HP motor.. Any help will be appreciated

 

[john from md]

Re: 1988 force 85HP running issue

Good luck finding a completed fuel pump assy. The only ones I have seen are on ebay and I would still change out the check valves. Later Merc fuel pumps won't work on earlier engines without modification of the cylinder cover.

Try www.crowleymarine.com for parts.

John

 

[cjac2879]

Re: 1988 force 85HP running issue

Good luck finding a completed fuel pump assy. The only ones I have seen are on ebay and I would still change out the check valves. Later Merc fuel pumps won't work on earlier engines without modification of the cylinder cover.

Try www.crowleymarine.com for parts.

John

When I type in the original part number on boats.net it says it was replaced with a new part... Will that one not work? I type in the force part number F2A658746 and this is what comes up

F2A658746
PUMP ASSY-3 CYL QPD=NO - Part replaced by MER-818071A 2

 

[john from md]

Re: 1988 force 85HP running issue

I don't use boats.net anymore due to their horrible shipping times and practices.

The part number I have for a 88 85hp is 818071A2 and it is no longer available.

John

 

[cjac2879]

Re: 1988 force 85HP running issue

I don't use boats.net anymore due to their horrible shipping times and practices.

The part number I have for a 88 85hp is 818071A2 and it is no longer available.

John

OK good.. I can get that part at a few different online retailers... Just wanted to make sure it fit

John, You have been an enormous help with me through this process.. You are an asset to this site

 

[cjac2879]

Re: 1988 force 85HP running issue

So, i didnt have much time today, but I went out to the boat, put the muffs on and she started right up.. She is now "coughing" at a higher idle.. I pulled the middle spark plug and it was wet and black (assuming it was oil)... I pulled the filter screen off the fuel pump, and there was alot of sandy material on the feed side of the filter.. While I had the filter off, I gave the ball a squeeze, and gas poured out of the filter, so I know there isnt a fuel line blockage..

I am just trying to decide if I want to buy the new fuel pump, or spend the $85 per hour to have someone look at it for me.

 

[cjac2879]

Re: 1988 force 85HP running issue

OK update time...lol

so to start the summer i replaced the fuel pump/fuel lines/new gas/spark test/compression test.

took it to the lake gave it full throttle a few times for only a secdon and the boat acted like it wanted to take off (front rose up and engine roared), but I was afraid to get to far away from the dock since I was alone.. Then I had a taking on water issue (since solved no worries) and I took it back and went to put it on the trailer.... I thought I would try it once more before i left, and had the same stalling as I increased throttle problem I had last year...

I have done everything I was confortable doing, and finally gave in and dropped it off at the marina on friday.

Any ideas as to what it could still be

 

[Austin8176]

Re: 1988 force 85HP running issue

I had a similar issue recently. I bought a 19 foot Bayliner Capri with an 85 Force outboard. Put it in the water and it kept stalling then dying. Turned out only to need a new fuel line (tank to the outboard). I used the external tank remedy initially to find the problem and it ran great with the external 6 gallon tank. Happy Boating

 

[ponchos_ta]

Re: 1988 force 85HP running issue

Did this engine overheat? My T-Stat stuck closed and I melted wires from the CDI to the engine. I fixed the grounded out wires and now I'm okay. My over temp buzzer never sounded either.