Sudden loss of power/RPM

[ReelFishingSWFL]

Hello I’m new to jet boating I’ve owned many boats with outboards and I’m definitely having a hard time transitioning I purchased a 2017 Yamaha 190 FSH and I’m having a bitter sweet relationship with it after running into several problems. I’m now experiencing a new issue and I’m looking for some answers so please feel free to jump in I’ll update as I go on trouble shooting. I’ve been experiencing an issue where I turn on the ignition switch and the motor turns on and then turns off after 2 seconds.. I then turn the key again immediately after it turns off and it cranks right up again BUT with a rough idle that lingers for a while then goes away.. today it did it about 3 different times however it turned on no problem after the second key turn.. As I was making my way back to the dock I was making way full speed 37mph and suddenly the rpm’s dropped to 5500 RPM and the motor started to rough idle. I quickly turned off the motor and checked the clean out hatch and it was clean nothing that I could see or feel (I was going over some heavy sea grass earlier in n the day and I pulled out loads of junk) I tuned it back on but this time it would turn off almost right away and I had to crank it up several times before I got the motor to turn over except this time the boat felt like it was shaking and wouldn’t go over 5500 RPM or over 10MPH.. I don’t think it’s cavitation because when if was and I may be wrong it would rev to red line and 95% of the time it was grass that needed to be cleaned out (unless theirs something stuck in there that I can’t see and reach to pull out) the way but still I should be able to rev past 5500 rpm if something were stuck right? I’m definitely not an expert so I don’t know if something stuck large enough would cause this issue.. I’m pulling the pump out tomorrow to look way in there to see if I can see anything lodged in the pump or shaft. Any suggestions or idea what it may be? Maybe someone’s had the same scenario and can share their experience I definitely appreciate it! I’m a fishing captain and my boat is my office I really need this boat back on the water asap! 🥹

 

[FSH 210 Sport]

When were the spark plugs last changed?

 

[ReelFishingSWFL]

When were the spark plugs last changed?

1 weeks ago along with fresh oil

 

[lazergeek]

I would verify spark on all plugs, It could be a bad coil pack. Also confirm you oil level is below the top line on the dipstick.

 

[I_squared_r]

Check that none of the spark plugs are damaged. Inspect the electrode that the gap is correct. Also inspect the insulator for a cracked body.
Check that the coil electrical connectors are properly connected.
Have you got gas recently? Maybe you got bad gas with water in it.
Check that the air intake isn't obstructed at all. There was a member that the insulation in the engine bay would cover his intake at some speeds.
Check your oil level that it isn't too high. A oil level too high will find it's way into the intake and cause drivability issues.

 

[ReelFishingSWFL]

Check that none of the spark plugs are damaged. Inspect the electrode that the gap is correct. Also inspect the insulator for a cracked body.
Check that the coil electrical connectors are properly connected.
Have you got gas recently? Maybe you got bad gas with water in it.
Check that the air intake isn't obstructed at all. There was a member that the insulation in the engine bay would cover his intake at some speeds.
Check your oil level that it isn't too high. A oil level too high will find it's way into the intake and cause drivability issues.

I’m on my way now to check these things you mentioned. I have suspicion that it’s the oil level I bought a kit from Yamaha that included the spark plugs the oil in the oil filter the previous owner told me not to fill it all the way Yamaha indicates that the 1.8 L high output takes 4 quarts of oil he told me to only put 3.5. My brother was helping me do the oil change and while I was not looking he put the full 4 quarts. I figured Yamaha recommends four courts no big deal so I left it like that. Now I’m wondering if that was a mistake so I’m on my way now to check the dipstick. However wooden issues have arrived immediately after the oil change? It’s been a week since the oil change you figured it start giving me issues immediately. Now that I’ve come to think about it I wonder if that’s my starting and turning off issue.

 

[I_squared_r]

I’m on my way now to check these things you mentioned. I have suspicion that it’s the oil level I bought a kit from Yamaha that included the spark plugs the oil in the oil filter the previous owner told me not to fill it all the way Yamaha indicates that the 1.8 L high output takes 4 quarts of oil he told me to only put 3.5. My brother was helping me do the oil change and while I was not looking he put the full 4 quarts. I figured Yamaha recommends four courts no big deal so I left it like that. Now I’m wondering if that was a mistake so I’m on my way now to check the dipstick. However wooden issues have arrived immediately after the oil change? It’s been a week since the oil change you figured it start giving me issues immediately. Now that I’ve come to think about it I wonder if that’s my starting and turning off issue.

Thats most likely your problem. I never get 4 quarts out of my motor. I think that I get 3 to 3.5 quarts. Also take your air filter out and check that it doesn't have oil on it. It would take time for the oil to make its way through the vent and into your intake. I think over time it clogs up that mesh flame arrestor (its before the throttle body) and the air filter. If the air filter is clean, then the mesh flame arrestor at the TB will probably will clear up on it's own. No harm done. A little extra lubrication for your cylinders.

 

[ReelFishingSWFL]

Thats most likely your problem. I never get 4 quarts out of my motor. I think that I get 3 to 3.5 quarts. Also take your air filter out and check that it doesn't have oil on it. It would take time for the oil to make its way through the vent and into your intake. I think over time it clogs up that mesh flame arrestor (its before the throttle body) and the air filter. If the air filter is clean, then the mesh flame arrestor at the TB will probably will clear up on it's own. No harm done. A little extra lubrication for your cylinders.

okayI’m working on it now I’ll be back and share my findings hopefully it’s that easy

 

[ReelFishingSWFL]

***UPDATE***
I just picked it up from the shop they found that my spark plugs were loose witch eliminated the ignition issue I was having. They also found that my oil level was low by 1.5q. They hooked it up to the computer and it had no codes. I took it out for a water test just now and it took off! After about 2 minutes of normal operation the same thing happened the rpm’s dropped to 6k RPM but this time I was able to go atoraste 15-20mph with a noticeable shake in the water pump area. I slowed down turned it off I checked the clean out hatch it was clear. I then cranked her back up and she ran fine again.. at this point I don’t know what to think.. could something be wrong with my pump?

 

[I_squared_r]

***UPDATE***
I just picked it up from the shop they found that my spark plugs were loose witch eliminated the ignition issue I was having. They also found that my oil level was low by 1.5q. They hooked it up to the computer and it had no codes. I took it out for a water test just now and it took off! After about 2 minutes of normal operation the same thing happened the rpm’s dropped to 6k RPM but this time I was able to go atoraste 15-20mph with a noticeable shake in the water pump area. I slowed down turned it off I checked the clean out hatch it was clear. I then cranked her back up and she ran fine again.. at this point I don’t know what to think.. could something be wrong with my pump?

I have 0 trust in the mechanic shop. How did your brother put 4 quarts and you were low 1.5qt? You should check everything for yourself like I outlined in the previous post.

 

[ReelFishingSWFL]

I have 0 trust in the mechanic shop. How did your brother put 4 quarts and you were low 1.5qt? You should check everything for yourself like I outlined in the previous post.

I agree with you 100% I just felt a little overwhelmed and figured a professional would have more of an impact. I’m on my way to check these things for myself now. He wasn’t very expensive and he was nice enough to fit me in without an appointment. I will check off your list now and get back to you. I can say that it’s running a lot better w.e he did definitely not 100%..

 

[ReelFishingSWFL]

Check that none of the spark plugs are damaged. Inspect the electrode that the gap is correct. Also inspect the insulator for a cracked body.
Check that the coil electrical connectors are properly connected.
Have you got gas recently? Maybe you got bad gas with water in it.
Check that the air intake isn't obstructed at all. There was a member that the insulation in the engine bay would cover his intake at some speeds.
Check your oil level that it isn't too high. A oil level too high will find it's way into the intake and cause drivability issues.

found oil in my Throttlebody and filter

 

[I_squared_r]

found oil in my Throttlebody and filter

The good news is that air filter is washable because it's an aftermarket filter from Riva. How's your oil level? You can also take the filter out to see if it runs better. I haven't had an air filter on my boat for the past 170 hours. The environment I boat in isn't dirty

 

[ReelFishingSWFL]

The good news is that air filter is washable because it's an aftermarket filter from Riva. How's your oil level? You can also take the filter out to see if it runs better. I haven't had an air filter on my boat for the past 170 hours. The environment I boat in isn't dirty

oil was over filled and dirty intake with oil along with filter

 

[ReelFishingSWFL]

oil was over filled and dirty intake with oil along with filter

***UPDATE***
I think I found the issue with my boat. When I unplug any of my first three cylinder coils the engine reacts to it however when I unplug my last cylinder coil the engine continues to run poorly… I’m assuming I have a bad coil?

 

[I_squared_r]

***UPDATE***
I think I found the issue with my boat. When I unplug any of my first three cylinder coils the engine reacts to it however when I unplug my last cylinder coil the engine continues to run poorly… I’m assuming I have a bad coil?

Move the coil to another cylinder and do the same test

 

[ReelFishingSWFL]

Move the coil to another cylinder and do the same test

Okay so I moved the coils around and the issue didn’t transfer.. I did a continuity check with a light tester and all the wires are getting power as well as new spark plug and still no spark in 4th cylinder. At this point I’m at a lost I have no idea what’s going on.. any additional tips? Thank you for all the help this far.

 

[I_squared_r]

Okay so I moved the coils around and the issue didn’t transfer.. I did a continuity check with a light tester and all the wires are getting power as well as new spark plug and still no spark in 4th cylinder. At this point I’m at a lost I have no idea what’s going on.. any additional tips? Thank you for all the help this far.

How did you determine that theres no spark in that cylinder? Are you using a spark tester or grounding the spark plug electrode on the motor somewhere while cranking/running it?

 

[adrianp89]

Swap plugs to see if it happens. Use a torque wrench to make sure they are down to 18.4lbs

 

[ReelFishingSWFL]

Swap plugs to see if it happens. Use a torque wrench to make sure they are down to 18.4lbs

okay did that and still no spark or life in cylinder 4.