1995 Johnson 88spl has the sneezes...

General Boats and Motors
1

My 1995 Johnson 88spl has a cold.
She sneezes when idling.
Runs great at anything above about 900 rpms.

History…
Cruising at about 4100 rpm, she stumbles a few times and drops down to about 3000 rpms and will do no more.

Spark test showed no spark on one cylinder. Removed lead from power pack to coil and the connector nearly fell off. I believe it was probably original. I think the power pack and coils are all original. Cheap crap only lasted 18 years.

Rigged it to see if the lead was the problem and it was. But, expecting that the other 3 leads were in similar condition, I installed a new power pack. She fired right up and idled nicely. The old girl is resurrected, again.

The manual says to check the timing after a power pack replacement. I have no timing light. 'Could get one, easily enough. And, she seems to run exactly as she has for the past 10 years.

Enough history.
She sneezes and will, on occasion, cut off when idling.

I’ve always thought sneezing was an indication of running lean at idle, pointing to dirty low speed carb jets. But, having installed a new power pack, I don’t know if the timing may be slightly off now. Could the timing being off cause ‘sneezing?’

Sneezing - idling nicely, then stumbling and releasing a single fairly sharp ‘sneeze’ of spray and exhaust out of the top exhaust ports, and, then, return to idling normally. If the sneeze is big enough, she shuts down.

Time for a carb cleaning?
Or, would checking the timing be worth my while? The procedure in the manual is a little bit of a pain if you don’t have a test tank and wheel.

17’ Henry O Hornet
26’ Palmer Scott

2

test tank and wheel would be for WOT timing, not idle
idle timing is what you would need to check for the sneezing, but most likely a dirty carb

www.teamcharlestonmarine.com
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3

Sounds like what I have been going through… Was able to fix mine by cleaning carbs, rebuilding fuel pump and blowing out all fuel lines to make sure there were no obstructions. If you do not have a fuel water seperator, you might have water sludge in the carbs, I did… I wiuld suggest installing one if you do not… But that idleing great with a pop, studder and then idling great repeated over and over is a lean condition, starving for fuel…

Key West 19’6" CC 115hp Merc
14’ Fast Craft w/ 60hp Merc

4

Hey Chris,

Thanks for the quick response and education. I was thinking I might need to do the full timing check procedure. But, you’re correct (as usual), since it happens at idle, WOT timing is not part of the picture.

Is has been a few years since the carbs got scrubbed.

Thanks again.

17’ Henry O Hornet
26’ Palmer Scott

5
quote:
Originally posted by chris V

test tank and wheel would be for WOT timing, not idle
idle timing is what you would need to check for the sneezing, but most likely a dirty carb

www.teamcharlestonmarine.com
www.joinrfa.org

^^^^^ I agree with the dirty carb being most likely on an idle misfire/ sneeze.

You did mention running it back on a dead cyl. You may have done it already, if not put in a new set of plugs. Lot’s of plugs don’t like that raw fuel dumped on them with out firing.

< Evil is simply the absence of God >

6

pitviper, fuel/water separator was checked for water. None found. Filled it back up with fuel and spun it back on (filter was new last spring with relatively little time on it).

Fred, good point about running on a dead cylinder. That plug may be pretty nasty. A new set of 4 couldn’t hurt.

And, a new set of carb gaskets and a cleaning is probably in order.

Thanks All.

17’ Henry O Hornet
26’ Palmer Scott