Advice on Sportster purchase

[sqzdog]

Hi everyone-

I am looking at a 1998 Sportster 1800. We took it out this morning and it was the first time the boat had been in the water after winterizing, so naturally there was a lot of smoke at first.

I know nothing about jet boats and have only owned outboard/ I/O, and inboards so the sounds and performance is not familiar to me.

A couple of questions:
-the left engine would cut off at idle and I had to repeatedly restart it.

-when accelerating both engines, there is a high pitched whining sound. I was expecting the boat to have immediate take off but it seemed like there was a delay. In normal terms, it seemed like a transmission slipping then it finally takes off. I wondered if part of it was cavitation.

-what RPMs should the engines be running at full throttle?

-a lot of water (gallon?) came out when we pulled the plug after only being in the water for about 30 minutes.

-is there a way to run the engines while out of water? earmuffs? Fake-a-lake?

I like this boat, but don't want to make a $4k mistake and have to listen to my wife rag me about it. Maybe all of this is normal, but I am just not familiar with jet engines.

I'd like to make a decision by the end of the day so any and all advice is appreciated.

 

[parrothd]

Sounds like it'll at least need, a full carb rebuild, and there's something causing cavitation which is causing the slow take off.

You'd need to remove the jet pumps and see whats up, could be a bad impeller & wear ring, or something stuck in there.

The boat should do approx 7200rpms, I'd do a compression check to check the engine, but sounds like it needs some work. There's owners/repair manuals that are free downloads so you may want to check those out..

 

[urbanskij]

I've got a '98 Sporster 1800 and the performance of the boat is great. It should get up and go without much of a delay. It does sound like you're getting some cavitation.

There are a couple of flushing points on the transom (one for each engine) that you can just connect a hose to. I usually flush mine through after every use as I run it in salt water.

What RPM are the engines idling at? Should be 1500 in the water. Once my engines are warmed up the idle is rock steady and there's very little smoke.

John

 

[sqzdog]

RPM's seem about right both idling and at full throttle. Do these engines usually make a loud whining sound when accelerating?

 

[roneagan@cfl.rr.com]

I have a 98 sportster and it jumps out of the water, you need to check the jet pumps. I there is to much clearence between the impeller and the wear ring it will cavitate and you do not get good thrust.. If you get under the boat when it's on the trailer you can look up into the pump with a flash light. You should see vey little clearence between the ring and the impeller. As for the water the exhaust manifolds may be leaking from the round plugs that are welded in after the casting is made.. Take a look at the plug on the engine side near the head.. I will almost guarentee it is leaking. None of this hard to fix if your handy, but if your not these can be expesive repairs..