1989 Force 85 - starting/idle issues

[Nemesis98]

Well, I was able to install the new piston, and put everything back together. Now the motor will start, but only if the throttle is in neutral and at full throttle. Once it starts, if I even move the throttle a bit, it will stall. And, it is hard to start - seems to flood alot. I haven't adjusted anything yet, as I'm not really sure what to do.

Unfortunatly, I don't have a way to test the compression. Any thoughts?

 

[maxum247]

Re: 1989 Force 85 - starting/idle issues

Pick up a Clymer manual for your year engine, it will give you details on how to do the compression test and what you need to do to adjust the timing, linkages, carburetors, so that your engine will start and idle correctly, etc!
You can use the search feature at the top of the i-boats page and search for what others have posted about simular problems and how to correct them!
max!

 

[Frank Acampora]

Re: 1989 Force 85 - starting/idle issues

Well, if you adequately checked the cylinder for scoring before you installed the piston, and did not put a piston in a marginal or deeply scored cylinder, then, compression should not be a major problem.

Timing and carb sync is rather important for good starting and proper running. Until you get a Clymers: I have in the past posted lengthy replies on how to Synchronize throttle and timing. This applies to all three and four cylinder Force engines. Since it takes me probably an hour to write, edit for understandability, and post that length reply, I don't like to repeat myself.

Go back and search past threads and you will find all you need to get the engine running well.

 

[Nemesis98]

Re: 1989 Force 85 - starting/idle issues

I ordered a Clymers manual, so hopefully I will be able to figure this out.

I do have a maintenance manual from Mercury that cover the Force motor, and according to that, the adjustments etc. for the idle are all set as they should be. (As far as I can tell that is) I am going to get a compression tester, just so I know what that is. I need to check to see if the plugs are working (is there an easy way to do this without getting zapped? The FAQs mention holding it against the engine block and cranking til you see blue sparks)

I took the carb air intake cover off, to make sure that everything was moving when it should move etc. Sprayed carb cleaner in there and things are shiniey and move smoothly. I am able to start it up, but as I mentioned before, only if the throttle is at full, and even then, the motor only idles like normal. When I was cranking it over/starting the motor, I noticed that fuel was dripping out of carb #2 when it was 'idling', and will pee out of a small hole on the side of the carb when I pump the fuel ball. Could this be a bad float needle in the carb? (Ok, I have to admit, I have no idea what that is, I read it in the FAQ's under 'motor won't start')

 

[Frank Acampora]

Re: 1989 Force 85 - starting/idle issues

That hole is actually a vent to keep fuel in the bowl at atmospheric pressure.

Caution: Science content! Atmospheric pressure is 14.7 PSI at sea level. So, air is pressing down on everything, including us, at 14.7 pounds per square inch. (as an aside, air inside the engine cylinders is starting at 14.7 PSI so when you read compression, the gauge reading is 14.7 less than actual pressure. So, a reading of 120 PSI is actually 134.7 PSI. That is why if you see a reading of PSIG, it is telling you PSI GAUGE. For our purposes in checking compression, it is not necessary to know actual pressure. PSIG is good enough and in the manuals, they do not even write it --they just say PSI and assume it is gauge.)

For a carb to function properly, the fuel in the bowl must remain at a constant height and a constant pressure. Without the vent, as the engine was using fuel from the carb, pressure within the bowl would change and fuel delivery would change. SO: The vent hole is provided to ensure that fuel within the bowl stays at 14.7 PSI.

If fuel is coming out of the hole or other orifices when you squeeze the primer bulb, then the needle on that carb is not seating and shutting off fuel supply when the bowl is full. You need to disassemble that carb, clean it, and check the needle seat. The float may be set too high, it may be hanging up open, the needle may be varnished stuck in the open position, the rubber seat may be bad and not sealing the needle, or there may be a piece of junk in the hole--not only partially clogging it, but also keeping the needle from seating.