1995 speedster high engine rev no power help

[bigcalibear]

I just bought a 1995 speedster and took it out for the first time.

At low RPM, 3500, or less both engine show the same RPM and sound and feel like they have equal thrust.

As I started to throttle up, the left engine would shoot to 6,000 to 7,000 rpm while the right was steadily working it's way up.

I could hear the left engine rev-up, but with no thrust. For most of the day, I would feather the gas lower on the left engine to try and match the right engine and after 15-20 seconds the left engine would rev down, get power and I was able to get up on plane.

At the end of the day the left engine would just rev-up and the rpms up to 6-7,000 again and no thrust. I didn't want to push it with just one engine so I limped in with both engines around 3,500 rpm which provided equal power.

Any ideas what is causing this and how to fix it?

Both engines were compression checked and plugs replaced when I first bought it and had it checked out at a mechanic.

I am a total mechanical idiot so any time you can take to explain what you think it may be or how to fix it would be greatly appreciated.

Thanks.

 

[RFoster130]

To really understand how these boats work might solve a lot of your questions. The basic concept of jet boats is jet propulsion. Normal prop boats use an external prop to push the boat along. Jet boats use an internal impeller. Think of it like a big fan blade. It sucks water up through the bottom of the boat and pushes it out the back through a smaller opening, creating force and moving the boat. That is the basic concept. When there is a restriction to the water flow, this thrust is greatly reduced. If there is a leak anywhere on the outlet side of the impeller, you get no thrust. This loss of thrust is called cavitation.

The intake on the bottom of the boat can become clogged up with weeds, sticks, and other debris. When this happens, the impeller no longer has water coming through it and therefore you have no thrust to move.

If it feels like something slipping, you may be experiencing cavitation. Could be something as simple as needing a new wear ring. A wear ring is like a gasket the incases the impeller. Read the How to that Dr Honda posted about changing your wear ring. It is very easy and can be done for like 60 bucks.

 

[captainjack987]

the 1995 speedster has one intake grate so if on engine was providing thrust the other should have been

 

[99SK04GTX]

Check wear rings and shaft seal

If your shaft seals are leaking and sucking air that contributes to cavitation. Even small objects, plastic, sticks can appear to cause big problems when lodged in the pump. Most people talk about carbon seals for shaft seals but I believe you have bearings and carrier that must be greased. Don't forget to grease the PTO fitting where the shaft meets the motor.