1970 85hp Johnson - erratic running - "surges"

[ukeman]

Idle - running problem

I've had my 1970 Glasstron a couple of years now - with 1970 85HP outboard, electronic shift. Had everything checked out and fixed when I bought it, but mechanic has since retired and having trouble finding help now.

Took boat out for 1st time this year a few weeks ago, first ran OK, then started cutting out when accelerating. Found leaks in gas fittings and bad pressure bulb and replaced those - also what I think was a leak in the vacuum line to the fuel pump, think I fixed that.

Then it was skipping - I had bad ignition wire connections - have temporarily fixed that (I think) and am in the process of getting new wires, ends, etc.

Now it starts (with some encouragement) and runs, but every few seconds, sometimes 10 or 15 second delay, it "surges" as if it's getting a bunch of gas all at once, then settles back down.

I did also dismantle the fuel pump, looking for problems, and think I've reassembled it correctly, but I will say the diaphragm seemed "stiff", not flexible.

any advice appreciated!

 

[Daviet]

Re: 1970 85hp Johnson - erratic running - "surges"

Have you checked the spark, is it firing on all cylinders? What do the plugs look like? You can use a timing light to check each plug wire while it's running to check for erratic spark.

 

[ukeman]

Re: 1970 85hp Johnson - erratic running - "surges"

Have you checked the spark, is it firing on all cylinders? What do the plugs look like? You can use a timing light to check each plug wire while it's running to check for erratic spark.

I installed new plugs and worked on the wires but I need to replace the wires, end caps and boots. I put a simple soark indicator on it earlier but I have a timing light and will try that.

Is there a chance the fuel pump is not functioning correctly? I disassembled it and the diapgr seems awfully stiff.

Steve