125 force won't run in water but runs GREATon muffs PLEASE HELP!!!

[Dsteere]

I have a 125 force that runs GREAT with the muffs on but as soon as I put it in the water and get a load on it it bogs down won't plain and will not exceed 3000 rpm .... Compression is 130,130,131,130 #2 cylinder has great compression and all have spark BUT if I pull the spark plug to #2 it makes no difference in how it runs when trying to start it with the motor in the water it " coughs" I'm at a total loss ...This is my first boat and my 3 and 4 year old are BEGGING me to fix it so we can go out this weekend so ANY help from the vets of iboats would be tremendously appreciated

 

[SkiDad]

how are you testing for spark ? Inline spark tester ? How do the spark plugs look - have you cleaned them or replaced them ? Does the squeezie ball on the fuel line stay hard or does it deflate ? Your idle should be about 1000 in neutral in the water and about 750 in gear. There is a FAQ at the top of this forum that has a link and sync video that might be helpful to you if you are mechanically inclined.

I'm just assuming you know this but you need a 50:1 mixture of oil and gas in these engines.

 

[gm280]

Try pulling off the spark plug wires one at a time when in the water to see which ones change the idle and which ones don't. The ones that don't change the idle when removed need attention because there are not firing and that IS your idle problem and, more then likely, the bogging issue as well. JMHO!

 

[Jiggz]

What year is this 125HP? And the main reason I can think of why it would not start while in the water is because of exhaust leaks. You can easily test this by running the motor with the cowling off while in the water. If it runs better it means there is exhaust leak not to mention you will obviously see it. Now for #2 cylinder with good compression you need to check if there is really spark in there. If none, switch parts around to see if the misfire follows, i.e., plugs, coils and cdm. If it does, then you know what is wrong. Double check also the trigger wires making sure none is broke or bare and touching to ground.

 

[gregmsr]

I once mentioned an exhaust leak causing bog down and some guy thought i was an idiot.......
Happened to me after motor swap....exhaust boot was not connected properly = bog down.