Seized engines in Yamaha XR1800?

[RXP-SWE]

Hi guys,

I know this is probably not really the correct forum to discuss a Yamaha XR1800 jet boat but as it probably share a lot of engine parts (if not all?) with the 155hp engine from the GP1300 it’s not too far off I guess

The history behind this is that I found an auction where they sell one of these boats with both engine seized. I can only imagine that they some how either forgot to fill two stroke oil or had some technical problem with the oil system.

So for my real questions, if you run out of oil and the engine seizes how bad damages are we looking at? Will a re-boar and a set of new pistons and rings probably take care of this or are we looking at more serious damage? Of course I realize that this is generally speaking and I would never know until I actually open the engines but what are your hunches?

What kind of money are we talking about in parts if it's just pistons, rings and gaskets?

Anybody know of any good forum for Yamaha jet boats?

Cheers,

[RXP-SWE]

Nobody?

[Hydrotoys]

You know. It really depends. The engine needs to be torn down, and totally inspected.

• Did it run lean?
• Did it have a case leak?
• Did it drop a power valve?
• Did it lose oil supply?
• Did it lose a crankshaft snout?
• Did the crank break in half.

You really don't know until you start investigating. Start with pulling the heads and posting up some pics.

Just asking what we "think" went wrong won't help you much.

[swamped]

I bought a "supposedly seized" up XR1800 last summer, it turned up the impellers were seized to the liners, 250$ later I was on the water .

You will never know what you need until you tear into it.

[spud]

If it did run out of oil the pistons will seize up before the crank gets hammered. That has been my observation anyway. Both seized at the same time would lead you to believe that unless they seized one then drove around on the other until they seized it.

[dav_dman]

if the back end filled with water then the internals are shot. As long as you have no holes in the cases or cyls it's all rebuildable. inspect cases and pull the heads and you'll know.