Number 2 cylinder not firing.

Good morning everyone. I just came across this forum and I think it the greatest thing in the world.... or a close second to drinking beer out on the boat on a hot, sunny, summer day....

Ref post "Cylinder not firing?"

I have almost the same problem with my 1989 Force 125HP engine.
The # 2 cylinder (of the 4 cylinders) is not firing. I have good compression, and good spark.
My guess is I'm having gas problems.

One person thought that I have a vacuum problem in the crank case. I sprayed starter fluid all around the casing seal checking for "pick-up". nothing.
I was wondering if the reads in the carb might have something to do with the cylinder not firing?

What other problems could cause the cylinder to not work?
AND....
If the problem is gas related, is their some kind of device I could rent to check the amount of fuel making it into the cylinder?

Thanks for your help.
Bill

Re: Number 2 cylinder not firing.

How are you making the determination that #2 cylinder is the one not firing?

Re: Number 2 cylinder not firing.

Check the diaphram in the fuel pump.If the comp is all about the same.Then do a spark test.J

Re: Number 2 cylinder not firing.

I replaced the diaphragm last year when I re-built the engine.

I know the # 2 cylinder is not working do to the fact I can take out the plug and or remove the plug wire and their is no change in the rough running of the motor. Hence, if I did that with #1, 3, or 4 cylinder, the engine would stop.

I cleaned out the screen in the side "drip port" I don't remember what the fuel drip-down thing is called that allows the fuel to trickle down from the top cylinder to the next cylinder below it. Thinking that might cause a problem but that didn?t help.

How do you know if the reed in the crab is bad?

How do you test the crank case vacuum?

How do you test id the right amount of fuel is making it thru the crank case & into the cylinder?

Thanks for the help.
Bill

Re: Number 2 cylinder not firing.

I would suspect that it's an ignition problem rather than fuel. Number one and two cylinders are fed by the top carburetor. If there was a problem with it, it would most likely affect both cylinders. I'm not an expert, but I've seen quite a few instances where the ignition system is not producing a good strong spark that only affects one cylinder. What year and HP motor do you have?

Re: Number 2 cylinder not firing.

I have a 1989 125HP force.
On another post some one mentioned having a stuck open reed that might be causing the cylinder to flood out.
Question for you????
Can a reed be stuck closed?

Bill

Re: Number 2 cylinder not firing.

Well...
I spent the weekend taking the crabs and the reed's apart to re-build. One thing I did was pull out two 3-?" long boles that hold the crank case to the head block and noticed that their was gas/oil on the bolts.... I replace the bolts with lots of RTV. Has anyone had a vacuum leak in the crank case from a couple of bolts that weren?t sealed?

Thanks
Bill

Re: Number 2 cylinder not firing.

If your compression is good then your reeds should be fine and...you should never use carb cleaner or starter fluid on outboards. It will destroy the rubber crankcase seal.

Re: Number 2 cylinder not firing.

Bill, to pull the plug wire while it's running ,without grounding the end is asking for coil/cdi problems,as this spark has to go some where and it will feedback to the coil/cdi unit.Ground the plug end to the block and then spin it over to check spark. If it's not a good blue spark ,it may not fire the plug under compression.Check it this way and post your results. Hope this helps

Re: Number 2 cylinder not firing.

What's the compression and re-check the diaphram.J

Re: Number 2 cylinder not firing.

Thanks guys'
I'll check the spark and compression again this weekend.

Last year as I was getting the sink & link done the repair shop replaced the diaphragm in the fuel pump. Should it be replaced every year? Over the last 15 years, I never had a problem with it leaking or losing it's prim. I don't have a problem replacing a $3.50 item every year if it makes the motor run better.

Bill