Help diagnose my engine problem

[Dean Andler]

Me and my family recently purchased a 2001 Yamaha ls2000 from a friend, only problem is the left side engine will cut out or start too about mid throttle while the other engine runs perfect. At first it wouldn't even get that far but the more it ran the more throttle it could take. Any suggestions what may be causing this engine to cut out?

 

[4x15mph]

- change the fuel filters
- change spark plugs
- take a compression reading of all cylinders on the bad engine
- when we're the carbs last rebuilt?
- engines cutting off completely can be the result of the safety switch under the rear plug/clea out hatch. Tape a nickel above the switch temporarily to see if the problem goes away. If so, adjust the switch

Also, congratulations on the new boat. Leave room for some time and money to make it perfect and you will have a great boat.

 

[Dean Andler]

- change the fuel filters
- change spark plugs
- take a compression reading of all cylinders on the bad engine
- when we're the carbs last rebuilt?
- engines cutting off completely can be the result of the safety switch under the rear plug/clea out hatch. Tape a nickel above the switch temporarily to see if the problem goes away. If so, adjust the switch

Also, congratulations on the new boat. Leave room for some time and money to make it perfect and you will have a great boat.

We changed the fuel filters and it ran great!! But we had a tow rope get sucked into the intakes, we pulled the boat out and cut all the rope out and dropped it back in! The left side engine started right up while the right side wouldn't even turn over. We got the boat home, checked spark plugs, pulled out the jet pump and nothing was lodged in there. The only other thing I can think of is the intake plugs. Any other suggestions?

 

[Dean Andler]

- change the fuel filters
- change spark plugs
- take a compression reading of all cylinders on the bad engine
- when we're the carbs last rebuilt?
- engines cutting off completely can be the result of the safety switch under the rear plug/clea out hatch. Tape a nickel above the switch temporarily to see if the problem goes away. If so, adjust the switch

Also, congratulations on the new boat. Leave room for some time and money to make it perfect and you will have a great boat.

It's like there is a cut off on the engine, won't turn over or even make the slightest of sounds when you turn the key.

 

[Dean Andler]

- change the fuel filters
- change spark plugs
- take a compression reading of all cylinders on the bad engine
- when we're the carbs last rebuilt?
- engines cutting off completely can be the result of the safety switch under the rear plug/clea out hatch. Tape a nickel above the switch temporarily to see if the problem goes away. If so, adjust the switch

Also, congratulations on the new boat. Leave room for some time and money to make it perfect and you will have a great boat.

Last thing is that we were only in nuatral when the ropes were caught.

 

[Bruce]

On top of the other suggestions add Seafoam to the next several tanks of gas.

 

[Dean Andler]

On top of the other suggestions add Seafoam to the next several tanks of gas.

I saw that it could've been water in the engine where I was towed but we pulled spark plugs and tried to start it up and it still wouldn't make any noise.

 

[Bruce]

I saw that it could've been water in the engine where I was towed but we pulled spark plugs and tried to start it up and it still wouldn't make any noise.

The cleanout plug hatch on the swim deck has two switches to test if it is open. If they are not fully depressed the engine(s) will not turn over. Some have taped dimes or nickels on the hatch where it presses the switch as a temporary solution. You can adjust the height of the switch if this is the issue.

 

[Dean Andler]

The cleanout plug hatch on the swim deck has two switches to test if it is open. If they are not fully depressed the engine(s) will not turn over. Some have taped dimes or nickels on the hatch where it presses the switch as a temporary solution. You can adjust the height of the switch if this is the issue.

I had went out early and checked that by having my friend hold the two buttons down while I tried to turn it over and still nothing.

 

[Bruce]

Does the starter engage?

The neutral switch also disengages the engine unless it is in neutral.

 

[4x15mph]

It sounds like you are saying there is no noise or action when you turn the key. Like others have said, there are safety's on the rear clean-out hatch and the gear shift (has to be in neutral).

- Doesn't sound like it is the neutral switch since you said the other engine starts fine
- Did you check the fuse in the CDI box at the rear of the engine compartment wall? There is a circular cap that you unscrew and there is a fuse in there
- Doesn't sound like the clean out safety since you had a friend hold it down. It could still be a bad switch
- Could be the ignition/key as one of the last things to check

 

[Speedling]

I am gonna say fuse is next logical step as well.

 

[Dean Andler]

It sounds like you are saying there is no noise or action when you turn the key. Like others have said, there are safety's on the rear clean-out hatch and the gear shift (has to be in neutral).

- Doesn't sound like it is the neutral switch since you said the other engine starts fine
- Did you check the fuse in the CDI box at the rear of the engine compartment wall? There is a circular cap that you unscrew and there is a fuse in there
- Doesn't sound like the clean out safety since you had a friend hold it down. It could still be a bad switch
- Could be the ignition/key as one of the last things to check

I will check the CDI box. But it doesn't make since because it was running perfect until the tow rope was caught in the intake and the engine just clicked off. Everything before that was fine, it would start right up, no rough idle or start up. I did try to start it 3-4 times before I figured out the tow rope was caught though but still it wouldn't even turn over as did the other but once the rope cut out of both the left side one started right up.

 

[Bruce]

@4x15mph, is there only one neutral switch? I thought there were two.

Another thought I had is, is something stuck in the jet preventing the engine turning over?

 

[4x15mph]

@Bruce , only 1 neutral switch in my dual engine ls2000. I think the throttle assembly is similar/same.

Can definitely be due to something still stuck. I would remove the pump regardless to make sure it is all clear even if the problem turns out to be something else.

 

[Dean Andler]

@Bruce , only 1 neutral switch in my dual engine ls2000. I think the throttle assembly is similar/same.

Can definitely be due to something still stuck. I would remove the pump regardless to make sure it is all clear even if the problem turns out to be something else.

We did remove the jet pump last night and nothing was lodged.

 

[Speedling]

Could be the starter or bendix as well then but if no click i think fuse or battery terminal come off?

 

[Bruce]

The fuse could have blown when the starter struggled against the rope.

 

[4x15mph]

Check the CDI fuse and report back

 

[0627Devildog]

The fuse could have blown when the starter struggled against the rope.

Agree. . . had that issue on my Sea-Doo Sportster a few years back.