gm_reynoldz
New member
I have a 1998 mariner 225 magnum EFI 2-stroke.
It has a bad stumbling issue.
the serial number is OG655392.
I had it in the shop in 2015 for a new lower unit and tune up, it came back running great.
I ran it maybe 8-10 hours in 2015 after the tune up
Late fall 2015, it started stumbling real bad, idles real rough, dies at idle, dies when put in gear.
It came on suddenly at the end of the year, I got it off the water and due to working out of town, it sat all of last year.
I got I out this year (last weekend) and did the following:
All new fuel, sucked the tank dry, ran it empty before putting a new fuel filter and new fuel in it.
Tank was clean, no water, fuel filter looked brand new.
Cleaned & re-gapped the plugs, verified all coils are firing with a timing light on each plug wire.
Plugs were clean, even after running at idle for 20 minutes, no carbon buildup, plugs look brand new, just have oily residue on them after running for a few minutes, the insides of the cylinders look the same. It is getting fuel and oil.
I tested all cylinders, they are all 90 PSI, except one, which is 95PSI, tested with a fully charged battery and throttle wide open.
No change, still runs terrible, almost like it is running on 2-3 cylinders.
So, I'm wondering what could be wrong that I haven't thought of, or is it just time for rings? 90 PSI is the very bottom of the range I believe. It is almost 20 years old, but probably only has 200-300 hours on it. The motor looks almost brand new.
It puts out a lot of oily/half-burned gunk on the lower unit and smokes a lot when ran. It stumbles and misses real bad and dies when put in gear.
Any help would be appreciated!
It has a bad stumbling issue.
the serial number is OG655392.
I had it in the shop in 2015 for a new lower unit and tune up, it came back running great.
I ran it maybe 8-10 hours in 2015 after the tune up
Late fall 2015, it started stumbling real bad, idles real rough, dies at idle, dies when put in gear.
It came on suddenly at the end of the year, I got it off the water and due to working out of town, it sat all of last year.
I got I out this year (last weekend) and did the following:
All new fuel, sucked the tank dry, ran it empty before putting a new fuel filter and new fuel in it.
Tank was clean, no water, fuel filter looked brand new.
Cleaned & re-gapped the plugs, verified all coils are firing with a timing light on each plug wire.
Plugs were clean, even after running at idle for 20 minutes, no carbon buildup, plugs look brand new, just have oily residue on them after running for a few minutes, the insides of the cylinders look the same. It is getting fuel and oil.
I tested all cylinders, they are all 90 PSI, except one, which is 95PSI, tested with a fully charged battery and throttle wide open.
No change, still runs terrible, almost like it is running on 2-3 cylinders.
So, I'm wondering what could be wrong that I haven't thought of, or is it just time for rings? 90 PSI is the very bottom of the range I believe. It is almost 20 years old, but probably only has 200-300 hours on it. The motor looks almost brand new.
It puts out a lot of oily/half-burned gunk on the lower unit and smokes a lot when ran. It stumbles and misses real bad and dies when put in gear.
Any help would be appreciated!