Unexpected acceleration

[oldandgrey]

Put boat in water first time since major work done. Started engine in neutral. Fine. Moved shift into forward and the boat wentfrom idle to full acceleration. Throttle control did not function. Had to pull key from dash to switch off engine. Tried again this time putting boat into reverse identical result
Removed boat from water. Any ideas?

 

[MacSeaDoo]

Need more details about your boat. What year and model? What work was done?

Most boats have a throttle cable connected to the throttle body. Some newer models are drive-by-wire with no actual mechanical connection and an electronic throttle body.

If yours is mechanical, first check the cable at the throttle body. There is an adjustment there. Also make sure they didn't route the cable through hoses that will distort it and cause it to pull the throttle assy open.

 

[oldandgrey]

The boat is a 2011 seadoo challenger 1800. All linkage is mechanical.

 

[Joe Starbuck]

Interesting problem. I have no direct experience with this problem, but that will not stop me from speculating. The engine idles when in Neutral, so we will assume the throttle body is in the idle position when in neutral. When in forward, it goes WFO so we will assume the throttle body is indeed WFO. I would first look at the control lever assembly and check the operation of the linkages to make sure there is no interference between the shift linkage and the throttle linkage and cable. Another theory is that the throttle is always stuck full open, but the fuel injection is keeping it at idle when the idle safety switch is actuated. This is probably not right, since the engine would stall from being too lean, plus I have no idea if the fuel injection is tied the the neutral safety switch. Let us know what you find.

 

[turbosl2]

Interesting problem. I have no direct experience with this problem, but that will not stop me from speculating. The engine idles when in Neutral, so we will assume the throttle body is in the idle position when in neutral. When in forward, it goes WFO so we will assume the throttle body is indeed WFO. I would first look at the control lever assembly and check the operation of the linkages to make sure there is no interference between the shift linkage and the throttle linkage and cable. Another theory is that the throttle is always stuck full open, but the fuel injection is keeping it at idle when the idle safety switch is actuated. This is probably not right, since the engine would stall from being too lean, plus I have no idea if the fuel injection is tied the the neutral safety switch. Let us know what you find.

I speculate the linkage if it is mechanical linkages. It’s a tight fit and someone has the cable crossed over maybe. If it were WOT all the time the engine would not start. It would go into flood clear and there would be no fuel being injected and it would not idle. I am banking on the linkage. Was anyone in the helm are replacing a shifter, throttle, or steering cable? Possibly causing the linkages to bind and cross? Just a thought.

Also is the throttle shifter remaining stationary at idle, (all the way down ) when you engage the forward or reverse shifter?

 

[Poormanracing]

Salt water brackish water could of gotten into throttle body and making it freeze open leave boat on trailer back it in slightly have someone shift the boat while you look inside it and see if it is they put the shift cable on the throttle under the control box under the control box the cable ends look the same and could be switched

 

[Mugwhamp 5]

The boat is a 2011 seadoo challenger 1800. All linkage is mechanical.

I have a 2010 challenger 210 its wired no cable

 

[turbosl2]

I have a 2010 challenger 210 its wired no cable

. Oldandgrey I don’t think they made a challenger 1800 in 2011. They are all 3 digit naming for the new models. 180, 210, 230…etc. 1800s we’re in the early 2000s.

 

[Joe Starbuck]

. Oldandgrey I don’t think they made a challenger 1800 in 2011. They are all 3 digit naming for the new models. 180, 210, 230…etc. 1800s we’re in the early 2000s.

 

[turbosl2]

View attachment 57161

Yup exactly. Only 1800 in early years

 

[Poormanracing]

Can we get over if it's a 1800 or a 180 we get what boat it is.guy added an extra zero.how did he make out fixing his boat

 

[Poormanracing]

Put boat in water first time since major work done. Started engine in neutral. Fine. Moved shift into forward and the boat wentfrom idle to full acceleration. Throttle control did not function. Had to pull key from dash to switch off engine. Tried again this time putting boat into reverse identical result
Removed boat from water. Any ideas?

How did you make out on your boat I want to help you out but gonna drop this thread because everyone keeps correcting what you posted on boat model

 

[turbosl2]

Can we get over if it's a 1800 or a 180 we get what boat it is.guy added an extra zero.how did he make out fixing his boat

How do I know that. I am always here to help. Nowhere did I get the info on what boat it is. Maybe it’s a 2001 1800, maybe it’s a 2011 180. Completely different. One is a Mercury marine outboard the other a 4tec. Just sayin…can’t help if I don’t know what I am dealing with.