1987 85hp force linc and sinc question

[Jcullen87]

I recently had a near disaster at a large lake with huge swells and ended up taking water into the exhaust of the gas tank. I removed the water from the gas tank, and removed the three carbs and removed the water from the fuel bowls.

Now when I put the muffs on it will run no problem. But when on the water it will die after 5-10 seconds on initial start then will stay started for less time on each additional start until it will not start at all so from what I have read and been told it is a back pressure problem because my idle/timing is not correct.

I read the sticky on how to do the linc and sync and step 2. it says to Loosen the screw(s) on the aluminum tie bar and let all carbs close completely. When I loosen the screws on the aluminum tie bar, all of my carbs are open, not closed.

So I am stuck at step 2 and am seeking help!

Please help!

 

[mauiboy]

Re: 1987 85hp force linc and sinc question

if your talking about the very front of the carbs that is the choke buterfly. if you look inside of the carbs youll see there is another set of butterfly that is the one that works the throttle.

 

[Jiggz]

Re: 1987 85hp force linc and sinc question

I guess we will have to start the diagnosis before the water contamination. Was the engine running properly before then? If it was I highly recommend you put it back together and diagnose the start problem instead. The back pressure they are talking about is mostly from the exhaust as the engine runs fine on muffs. When running on muffs, is the cowl off the engine? How about try running the engine under a garbage can and troubleshoot from there?

 

[Jcullen87]

Re: 1987 85hp force linc and sinc question

Okay.

Before the water contamination it was running fine. Then, occasionally while at full throttle it would slow down for a few seconds then rev back up and would repeat this. Shortly after it started doing that, my starter went out. I had the starter rebuilt, then the circuit breaker blew. I fixed that, then the fuel pump went out. I rebuilt the pump and then had the water incident which I have also cleaned out.

Today I ran the engine with and without the cowl with the same result which was that it was running fine. no hiccups. I would have to choke it to start it most of the time though but it has been that way for this engine since I got the boat. I figured it was because it was an 87'.

The trashcan is a good idea, but I figured I would take it to a local lake this weekend after checking the timing and adjust the idle etc while on the water.

 

[Jcullen87]

Re: 1987 85hp force linc and sinc question

I replied to mauiboy's post yesterday but seems it didn't take.

So, thank you for the information on the second set of butterflies inside the carbs. I am now at step 6 and need a timing light.

Do I need a marine timing light or will any timing light that can handle the correct amount of RPM's do?

 

[Jiggz]

Re: 1987 85hp force linc and sinc question

I recommend doing the garbage can run first. This is as close as you can get being in the lake. If it doesn't ran good with the garbage can it neither will it ran good in the lake. As for timing light, yes a std auto timing light will work. Remember you can also use a static method which does not require a timing light.

 

[jerryjerry05]

Re: 1987 85hp force linc and sinc question

If you've never touched the timing linkage??
It probably isin't the problem.
Any light will work.
Running fine and slowing down? Possible air leak in the fuel line.Or the tank vent clogged?
Change the fuel lines and remove any inline connectors.
Idle 750-800 in the water in gear.
In the drive 1100-1200

Hey Jiggz static timing without a light??
I'd like to learn that???

 

[foodfisher]

Re: 1987 85hp force linc and sinc question

I vaguely remember something about pulling #1 plug, grounding it ,and watching for spark as you turn the flywheel and noting the mark/s location. I've got a light so it didn't sink in.

 

[Jiggz]

Re: 1987 85hp force linc and sinc question

Jerry, static means no motion or doesn't move. So why would you need a timing light? I'm quite sure you are familiar with a TDC tool and know exactly what I'm talking about. If you don't there is no reason to learn static timing instead just stick with dynamic timing.

 

[Jcullen87]

Re: 1987 85hp force linc and sinc question

I did not get to work on the Boat yesterday. I was doing honey-do's.

I will check the vent and gas lines and most likely buy a new line and bubble.

Will let you know how it goes. Thanks again for all the help everyone.