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Spark plug gaps closed

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xGOODYx

New member
I have bought my first boat so i'm very green when it comes to boating and outboard motors. I have a 99 triton with a 2000 Johnson 115. When I water tested it prior to purchase it appeared to run smoothly with no problems(it was very cold and we did not stay out long). I have had it for a few months but due to weather and flooding I just took it out for the first time. It would not idle at first and even when it warmed up it had a slight miss int it. It ran great at high rpms. When getting back to the ramp it would not idle in gear and had difficulty pulling it on the trailer. I pulled the plugs when I got home and 3 of the 4 plugs had gaps that were almost completely closed. I have read that this is a result of foreign material making into top of the piston or the piston itself hitting the plugs. From my research it sounds like I have wasted a lot of money on this boat. If anyone has any insight as to why this may be happening please let me know. I have not changed the plugs which I plan on doing. As I said i'm very new to boating and do not have a bore scope or compression tester. No knocking or odd sounds as far as I can tell other than the miss at idle. Thanks in advance for any help you can give me.

Yours truly,
One very nervous newbie.
 
Model # of the motor ??-----Talk to the seller and find out when those plugs were installed.----Post the number you see on those plugs.
 
It would seem unlikely that any foreign object damage would close the gap on three of the plugs and not cause some serious damage to other internal parts. Possible that the plugs were dropped when installed and the gap was never corrected before they were re-installed? A Boroscope, inserted through the spark plug hole, would be a useful tool to inspect any internal cylinder damage. These scopes have come way down in price. Here is a link to a $30 model on amazon.


https://www.amazon.com/Atomic-Beam-...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=
 
Any pictures of the plugs ?------Is oil injection in service or mixing at 50:1 on this motor.-----Seems strange that it would even run at all with 3 plugs like that.
 
Please remove all the plugs and with a fully charged battery, do a compression test. Be sure to put the muffs on with a little water to lube the water pump while your doing the testing. The local auto parts store may loan you a commercial quality compression tester.
 
racerone said:
Any pictures of the plugs ?------Is oil injection in service or mixing at 50:1 on this motor.-----Seems strange that it would even run at all with 3 plugs like that.
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Having a hard time inserting a pic. The oiler was disabled when I bought it and I am pre mixing the gas.
 
Thank you for this advice. I will do a comp test and let you know the results, may take some time very busy life and work right now.
 
Sounds like they installed one correct plug and then installed 3 that were to long. Check the numbers on the plugs.
 
How could that be? Maybe they are ALL wrong, but one was loose or had a repaired insert keeping it slightly higher in the head.
 
xGOODYx said:
Thank you for this advice. I will do a comp test and let you know the results, may take some time very busy life and work right now.
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Have not forgotten about you all. I will post an update when I get some testing done. I plan on buying the new plugs, and looking for a compression tester this weekend.
 
Sure, hold piston at bottom of stroke with a dowel in the spark plug hole. Next rock the flywheel back and forth...find out fast if there's any slop.
 
I do it a little different. Bring the piston to top dead center. Then stick a long skinny screw driver in the plug hole. Next rotate crank until you see screw driver going down. Then stop and hold crank shaft. At that time push down on screw driver. if there is any play in conn rod or wrist pin you will at that time pick it up
 
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Great, better system, done that too. If you bring piston heading either up or down, then reverse crankshaft direction while turning flywheel.....you can also feel the slop if it's present.
 
When I water tested it prior to purchase it appeared to run smoothly with no problems(it was very cold and we did not stay out long). I have had it for a few months but due to weather and flooding I just took it out for the first time. It would not idle at first and even when it warmed up it had a slight miss int it. It ran great at high rpms.​
Click to expand...
If it had three bad rods it would sound like a rocks in a gallon metal can when running
 
Agreed----Some of us could hear the rattle.-----But for some they are looking at their first boat at a price they can afford.-----Seller said " motor runs " and then they heard it run.------What could be wrong if it runs !!
 
Interesting! Anyone have any actual specs on acceptable "Slop" It would seem that removing a cylinder head might be good way to accurately diagnose this condition.
 
I never looked at the degrees of "slop" but years ago I could calculate how close a small block Chevy was to "jumping the timing chain". If 7 degrees of play was felt between crankshaft and camshaft movement, then you needed to change cam sprocket and chain very soon. As a general rule......ANY movement perceived using the aforementioned proceedures....is not ideal or acceptable. The clearance in these needle bearings is likely going to play out to less than 3 or 4 degrees of play on the flywheel.
 
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Ok finally got to work on it. Replaced all four plugs. Let it run on muffs to warm up a bit. Removed all four plugs and ran compression test on each cylinder. All four were at 140 give or take 1-2 pounds. It fired up great and ran smooth on muffs. When I removed the plugs none of the gaps had been altered. I will run at full throttle next nice day and look at plugs again. Will post update asap.
 
Probably hasn't been a nice day, eh? Gonna cut alot of folks income the next few weeks but fuel prices near 2 bucks here in Duluth.
 
After some conversion calculations, i can tell the fuel price here (about). 1 Liters = 1,5 Euro and 1 US Gallon is 3,7 Liters. So then 3,7 x 1,5 = 5,5 Euro, and 5,5 Euro is 6,12 USD
 
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