1987 force 85hp, fuel line problem?

[rexfunk]

Hey all,

I've got a Force 85 HP, Model 856X7A, Serial 1331. I installed it on my 1961 Crestliner Chieftain two months ago, after running it on a test stand.

Y'all helped me get this motor running this summer, and it was going great in a tub of water in the driveway. I let it sit two months while I fixed up the boat itself, electrical system, and mounted the engine on the boat. I ran it several times installed on the boat in a tub of water and saw no problems.

I put fresh fuel in the portable tank and I took it out on the lake today: it barely ran!

Here's the one thing that I changed on the engine: My old fuel line and bulb was beat. I replaced the bulb and line, only the fuel line on there was such a small inner diameter that it barely fit over the nipple on the fuel supply filter at the engine. I bought a 3/8" inner diameter line for fuel supply, new generic SeaSense bulb at Walmart and hooked it all up.

Today the engine ran super-rich, apparently. I could only idle it with the throttle cocked to 3/4 open. It missed repeatedly at all power settings, and would stall out below half-throttle. I couldn't go into reverse without stalling, I got it to go forward, barely, and then took it off the dock. I thought if I ran it hard it might clear it out. It ran great for about 5 minutes, except for the occasional miss. Then it bogged down and would only give me about 20%power on the way back to the dock, even with the throttle at 3/4. Full throttle would stall it out.

Checked the plugs when I got home, and they're all very dirty. The bottom plug was pitch black and greasy/ sooty. So I fouled the plugs during the endeavor. Over-rich, I assume.

Where do I start?

Is the inner diameter of the fuel line a factor? If so, what I/D is required for this engine? I have the Clymer manual, but I can't find that spelled out anywhere.

Also, I haven't taken y'all's advice yet about changing the water pump either. I've read the manual and I'm not sure I'm up to the task. I was going to run it around the lake and put it through it's strides before I dug into that project.

So at this point, would you recommend taking this to a shop, getting the water pump done and asking them to tune this thing up? Should I replace this fuel line and tackle the tune up myself?

Does anyone have any clue what's a fair price estimate on a water pump install for this engine, and also a tune up?

Don't know where to start, or what to do. Little discouraged at this point. I was so close! Any ideas?

Thanks,
Rich

 

[roscoe]

Re: 1987 force 85hp, fuel line problem?

Could be a bad fuel line or bulb, chunks of plastic stuck in the check valve in the bulb. Try putting the old one back on.
Did you put the bulb on facing the right direction.

 

[rexfunk]

Re: 1987 force 85hp, fuel line problem?

Could be a bad fuel line or bulb, chunks of plastic stuck in the check valve in the bulb. Try putting the old one back on.
Did you put the bulb on facing the right direction.

Roscoe,

My old line and bulb looked so beat, I threw them away. The new fuel line is brand new and so is the bulb. What would you suggest from here?

 

[rexfunk]

Re: 1987 force 85hp, fuel line problem?

Could be a bad fuel line or bulb, chunks of plastic stuck in the check valve in the bulb. Try putting the old one back on.
Did you put the bulb on facing the right direction.

Roscoe,

My old line and bulb looked so beat, I threw them away. The new fuel line is brand new and so is the bulb. What would you suggest from here?

Oh, yeah. I did check, it is facing the right way.

 

[eurolarva]

Re: 1987 force 85hp, fuel line problem?

Walmart primer bulbs have a bad reputation. They tend to not work worth a crap. Seems to me if the bulb does not slide snug onto the fuel fittings you have the wrong size. Disconnect the fuel fitting from the motor end and pump the bulb and see if you get a free flow of gas coming out the end of the hose.

What could be your problem is that when you removed the old hose a bunch of crud got into your fuel system and the carbs and fuel pump probably need cleaning. If you can take off one of the floats on your carbs that is where you will find specs of black. To get the lower unit impeller changed out will probably run you about 100 bucks. Fuel service, tune up and diagnostics probably another 200 bucks. If it were me I would buy a factory fuel bulb and rebuild the carbs and fuel pump then go from there.

 

[Matthew A.]

Re: 1987 force 85hp, fuel line problem?

You may wish to check the particulate screen inside the fuel pump itself for chunks of crud. If you used teflon tape to seal any threaded connections in the fuel line, sometimes the tape can get pulled across the opening of the connector as it is threaded. Thus, blocking the flow of fuel. It may also be an air leak somewhere in the fuel line connections.
I just got done rebuilding the carbs on my 88 85 hp Force. Upon making adjustments to the air/fuel mixtures on each carb I found that making adjustments on the water as opposed to while on the trailer is far more reliable. Adjustments I made while trailered were useless. Not only would the motor not idle once on the water, it wouldn't start either until I made adjustments to the idle speed screw. I now know that being sure to adjust the throttle linkage to spec. also is of great importance. I was having difficulty getting the motor to run until I took the time to get the throttle cam correctly set. Along with adjusting the linkages between each carb that control the opening of the carbs shutter to get them into sync with eachother. I have also learned that paying attention to the small details involved in the carb circuit on my Force can make all the difference in how this motor behaves. It's a learning curve that finally has my motor purring like a kitten and rewarding me with over 4 and sometimes as much as 6 mpg. When for nearly two years I was lucky to get over 3 mpg.

 

[Matthew A.]

Re: 1987 force 85hp, fuel line problem?

P.S. Depending upon the type of quick connect fuel connector used to connect the fuel line to the fuel tank, could be an issue that is affecting your motor. I have found that most of the quick connects are junk and fail in time. Either they completely come apart or create to much flow restriction or don't seal correctly and allow air to enter the fuel line. Another mistake that I have made that can make a motor run like crud or worse, can even completey destroy a piston is not being sure that the vent screw has been loosened on portable fuel tanks.

 

[rexfunk]

Re: 1987 force 85hp, fuel line problem?

Thanks, all. That's a start. I suppose I'll order a factory fuel line first. I'll check a couple float bowls and see what I see. I have the rebuild kit for the fuel pump, but haven't jumped in there yet. I'll get started on it. You know, I was kinda hoping to just throw this thing in the water and have it work for me. Overly optimistic, or just naive, I now realize.

Hey, I got a quote of $125.00 for the water pump (not including the pump parts) and $125.00 for the tune up, except it's $90.00 per carb if they need to rebuild them (they don't need it, I took them apart and cleaned them at the start of this project.) and then shop fees and 3.5 percent tax on the whole deal.

Is that a little high?

-Rich