2000 johnson 115 2 stroke missing !!! Need expert advice

2000javelin

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Jun 28, 2015
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2000 model javelin boat with matching 2000 Johnson 115 2stroke on the back. boat is all original never messed with. still has the factory oil injection system on it. Engine has always ran great.... no problems. The other day we took it out and got maybe a mile downriver and the boat felt like it went into neutral sputtered and cut off. after 20 restarts and sputtering and cutting back off we were able to get it to the trailer.

first inspection revealed a primer bulb that would not prime. Replaced the fuel filter and water separator filter.. (also threw in a new set of plugs due to all of the missing on the way back home) .......primer bulb pumps up.... great fixed it....NOT!!!


With the motor on the water hose in the yard the motor will start and run but its still missing. If I bring the throttle up to raise the rpms it will clear up for a few seconds and run great, but then goes back to missing.

I thought maybe it was the ignition coils. A trip to the local boat mechanic got me a set of used good coils to try . Swapped them in hoping for a change but no dice. So its definitely not the coils. New plugs. Disconnected each plug 1 at a time. Definitely can tell when you pull each plug wire off. Good spark jumping to each plug from the wire when I hold it near the plug.

Had a thought... maybe its bad gas due to the fact that I had just filled boat up before it messed up. Disconnected fuel line from engine side of primer bulb to eliminate entire boat fuel system and ran the line with a splice into a gas can of known good fuel (100octane aviation fuel). Start the boat up and let it run for a while but absolutely no change.

I have inspected and examined all full connections (why they used zip ties is dumb to me) and I cannot find any leaks. Wiggled jiggled all electrical connections and disconnected all junctions and inspected for corrosion or damage. I cannot find anything wrong. This is driving me nuts!!!!

Tonite when messing with it I noticed a dinger went off and the light on the dash that says "no oil" was on. I immediately cut the boat off. Inspected oil tank which was 3/4 full. Let it set for a minute and then restarted it..... light did not come back on.

when boat is running (missing 90% of time) it is smoking really badly. I had attributed this to the fact that not all the all and fuel is getting burned.

Im not a boat expert or mechanic....nor do I have the funds for a major mechanic bill.

3 things Im wondering but need help with as I don't have funds to just start replacing parts

1. is the boat getting too much oil? Why did the no oil light come on? Is the oil injection system going bad?

2. the power pack? could this possibly be the source of my miss?

3. fuel pump? Not getting enough fuel?
 

Chris1956

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Mar 25, 2004
Messages
28,558
So it has spark on each cylinder? What is compression of each cylinder? What cylinder is missing? What does spark plug of missing cylinder look like?

No Oil alarm means the OMS pump was not seeing oil. If it happens again, it makes sense to premix until you get it sorted out. The oil injection is a good system, so don't sack it unless you have to.
 

2000javelin

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Jun 28, 2015
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Compression is good 115 on all cylinders give or take 3 or 4 psi varience. It seems the miss is not a single cylinder more so a random missfire. I have good strong blue spark going to each plug.
 

2000javelin

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Jun 28, 2015
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When i first raise the rpm to half throttle or so the boat runs great.....just like it always has. But after 5 or 6 seconds it will start breaking up and missing. I dont think theres any internal engine damage.
 

2000javelin

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Jun 28, 2015
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any help from anyone is greatly appreciated. Im at my end with this stupid thing !!!!!! Any Johnson experts?
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,558
Well, from your description, it sounds electrical. Check the CDIElectronics web site troubleshooting procedure My service manual suggests the issue might be the powerpack, and describe two tests to isolate the issue to the powerpack. You might invest in a factory Service Manual, as your issue is difficult to diagnose.
 
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