- Messages
- 1,565
- Reaction score
- 891
- Points
- 247
- Location
- Ottawa, Canada
- Boat Make
- Scarab
- Year
- 2015
- Boat Model
- 165 G
- Boat Length
- 16
There are many pros to a jet drive engine, but one of the biggest issues is sucking up unwanted items. It's definitely one of the less desirable aspects of a jet drive.
The manual states that you should NOT run the engine unless you're in 3+ ft of water. If you're in less than that, there's a risk of sucking up debris depending on what's on the bottom. The risk is even higher if you're not moving forward since a tornado is formed under the boat which sucks things up.
The absolute TINIEST particle that gets wedged inside the pump (aka impeller area) such as a shell, tiny rock, tiny stick, tiny piece of plastic, etc. can cause issues.
Contrary to popular believe, weeds are not commonly an issue on our boats. Can they be? Yes. If you start driving in a marsh with tons of heavy duty weeds, or you're in the ocean over thick stuff, or go through a long patch of smaller weeds, things can accumulate or block the intake. In some cases, some plants are so rugged, they can wrap around the drive shaft as if it's a rope. But weeds in general are not a super common problem.
Weeds are usually a problem at the intake grate level. What goes through the pump is usually chewed up and spit out. But if weeds accumulate on the grate and don't go through, it blocks the water flow to the pump and can cause a serious loss of speed. If this happens, you have two choices, go under the boat to remove it (bonus points if you live in warm water areas, otherwise sucks to be you, I know the feeling), or you can try a "flat spin" technique that MAY work.
Assuming you can accelerate somewhat, try and get just enough speed to cause the biggest wake possible behind you. Maintain that speed. While at that speed, turn the steering wheel hard to either direction and when the spin starts, kill the engine by pulling the emergency lanyard. The goal here is to NOT have the reverse bucket come down in front of the nozzle (aka, don't put the boat in neutral). If you've done this right, your boat will slowly spin and the wake will catch up to you. You'll find your boat "surfing" backwards that wave and in the process, water will flow in reverse through the jet nozzle and OUT the intake grate. If you're lucky, the debris on the intake grate may flush out and away. Didn't work? Try again a few more times in different directions. There's a good chance it will work. Even if it's not enough, it may be just enough to get you on plane and rip the rest off at speed.
Again, this isn't super common but that depends on your waterways and behavior.
The other issue is you suck up something inside the pump. If you do, the classic symptom is normal behavior at slow speeds, but when you accelerate, the boat may vibrate, sometimes violently and you don't seem to have any power. It's described as "it slips" or "doesn't seem to grip". This is called cavitation. The debris inside the pump is preventing the pump from working properly and it can't produce the normal pressure required.
This is the sucky one (ha! Hilarious, sucky... I know, I'm a qualified dad). I recommend keeping a mask onboard, a waterproof flashlight and VERY long needle nose pliers that allow you to reach inside the grate from under the boat and reach the impeller. Look at it and measure while it's on the trailer. This is crazy you say? Yes. Agreed. Is this common? No. But it does depend on the waterways you're on. I'm lucky to live in very pristine waters in Canada. Garbage essentially doesn't exist. Since owning my boat in 2017, running in extremely shallow waters of 12", even at idle speeds (not recommended), I've only ever had this problem once. And I was able to use pliers to pull it out. It was a nice summer day, all good. But you do need to have a good breath, keep calm and have some luck.
Otherwise, you'll need to get the boat out of the water and onto a trailer. Once there, you can look very carefully through the intake grate and through the jet nozzle (from the stern, with the boat in forward so the bucket is out of the way), and see if you can spot a tiny or big piece stuck in there. If so, pull it out by any means necessary EXCEPT PULLING OFF THE GRATE. Refer to "New Owner? Read This!" thread for why. Long pliers or a piece of rebar may be useful.
If you absolutely can't remove it, it's time to pull the pump OUT of the boat. This is NOT hard and requires very simple skills and tools. The first time it's scary, but it's worth learning. Here's the best video to see the process:
It's for a different brand of boat, but they use the same BRP engine and systems.
Pulling the pump is the absolute best way to inspect and remove anything.
The manual states that you should NOT run the engine unless you're in 3+ ft of water. If you're in less than that, there's a risk of sucking up debris depending on what's on the bottom. The risk is even higher if you're not moving forward since a tornado is formed under the boat which sucks things up.
The absolute TINIEST particle that gets wedged inside the pump (aka impeller area) such as a shell, tiny rock, tiny stick, tiny piece of plastic, etc. can cause issues.
Contrary to popular believe, weeds are not commonly an issue on our boats. Can they be? Yes. If you start driving in a marsh with tons of heavy duty weeds, or you're in the ocean over thick stuff, or go through a long patch of smaller weeds, things can accumulate or block the intake. In some cases, some plants are so rugged, they can wrap around the drive shaft as if it's a rope. But weeds in general are not a super common problem.
Weeds are usually a problem at the intake grate level. What goes through the pump is usually chewed up and spit out. But if weeds accumulate on the grate and don't go through, it blocks the water flow to the pump and can cause a serious loss of speed. If this happens, you have two choices, go under the boat to remove it (bonus points if you live in warm water areas, otherwise sucks to be you, I know the feeling), or you can try a "flat spin" technique that MAY work.
Assuming you can accelerate somewhat, try and get just enough speed to cause the biggest wake possible behind you. Maintain that speed. While at that speed, turn the steering wheel hard to either direction and when the spin starts, kill the engine by pulling the emergency lanyard. The goal here is to NOT have the reverse bucket come down in front of the nozzle (aka, don't put the boat in neutral). If you've done this right, your boat will slowly spin and the wake will catch up to you. You'll find your boat "surfing" backwards that wave and in the process, water will flow in reverse through the jet nozzle and OUT the intake grate. If you're lucky, the debris on the intake grate may flush out and away. Didn't work? Try again a few more times in different directions. There's a good chance it will work. Even if it's not enough, it may be just enough to get you on plane and rip the rest off at speed.
Again, this isn't super common but that depends on your waterways and behavior.
The other issue is you suck up something inside the pump. If you do, the classic symptom is normal behavior at slow speeds, but when you accelerate, the boat may vibrate, sometimes violently and you don't seem to have any power. It's described as "it slips" or "doesn't seem to grip". This is called cavitation. The debris inside the pump is preventing the pump from working properly and it can't produce the normal pressure required.
This is the sucky one (ha! Hilarious, sucky... I know, I'm a qualified dad). I recommend keeping a mask onboard, a waterproof flashlight and VERY long needle nose pliers that allow you to reach inside the grate from under the boat and reach the impeller. Look at it and measure while it's on the trailer. This is crazy you say? Yes. Agreed. Is this common? No. But it does depend on the waterways you're on. I'm lucky to live in very pristine waters in Canada. Garbage essentially doesn't exist. Since owning my boat in 2017, running in extremely shallow waters of 12", even at idle speeds (not recommended), I've only ever had this problem once. And I was able to use pliers to pull it out. It was a nice summer day, all good. But you do need to have a good breath, keep calm and have some luck.
Otherwise, you'll need to get the boat out of the water and onto a trailer. Once there, you can look very carefully through the intake grate and through the jet nozzle (from the stern, with the boat in forward so the bucket is out of the way), and see if you can spot a tiny or big piece stuck in there. If so, pull it out by any means necessary EXCEPT PULLING OFF THE GRATE. Refer to "New Owner? Read This!" thread for why. Long pliers or a piece of rebar may be useful.
If you absolutely can't remove it, it's time to pull the pump OUT of the boat. This is NOT hard and requires very simple skills and tools. The first time it's scary, but it's worth learning. Here's the best video to see the process:
It's for a different brand of boat, but they use the same BRP engine and systems.
Pulling the pump is the absolute best way to inspect and remove anything.
