Speedster - Starboard Throttle....

[PburgDooey]

I lubed up my throttle cables the other day, they operate nice and smooth, and always have. I do it for the preventive maintenance, as supposed to.

Then..Over the weekend, I noticed the starboard throttle handle had two minor issues

1) It was lubed so nicely, it felt "loose" and would slip down as I was underway. I had to keep my hand on it to maintain throttle speed.

2) It is not sync'd up with the port side. I mean, I can run them at the same RPM just fine, but i have to stagger the levers. At about 5000 RPM, the starboard throttle is about an inch more forward than the port. Not a huge issue, but its kind of annoying holding them staggered like that.

Do i just have to pull the starboard cable tighter on the linkage at the engine?

Any other ideas?

 

[Dr Honda]

1) There is a drag adjustment in the handle assembly. Lift out the levers, and tighten it a little.

2) It never is... it never will be... that's why they give you 2 levers, opposed to tying the throttle cables together on one lever. As soon as you attempt to get them in perfect synch... the plugs will slightly foul, and the engine will tun at different speeds again. Also... seadoo uses 2 different impellers in many of the two engine boats. SO... at any given load... the engines are at 2 different RPM's.

FYI... one impeller is a lower pitch. That helps with "Out of the hole," and the other is high... and that helps with tops speed.

 

[PburgDooey]

Thanks. That makes sense.

One more question..

I've had this boat for awhile, and I'm pretty mechanical, do my own work, and know a lot about it.

However, I'm stumped on one issue. When at lowest idle speed, either in F or N, there is "thump thump" sound...like someone stomping their foot. It goes away as soon as i slightly idle up. What is this? Is this just how it sounds?

Its always sounded like this for the 3 years i've had it. I know some of the older speedsters sound awful when they idle, even when they are in perfect running order. At least this model doesn't "rattle" like those do.

I'd to know what the thumping sound is though. Do you experience this?

 

[Dr Honda]

That's the infamous SeaDoo pump knock. It's totally normal. Basically... seadoo doesn't load the impeller shaft, and it only has a rear thrust bearing. So... at low RPM's... the impeller shaft will knock back and forth... but once you give it a little throttle... the pumps load... and the knock goes away.

 

[PburgDooey]

Thanks, thats what I thought. Nice to get the confirmation.

I have always owned boats. This is my first jet, however. If you hear a knock like that coming from an I/O or an outboard....its not good!

 

[Dr Honda]

Yep... I understand. There are lot's of gears, bearings, and U-joints in the I/O. A seadoo drive is so basic... noises aren't always issues.