PeachParts Mercedes-Benz Forum - View Single Post

dannym · #1 06-05-2007, 08:32 PM

I posted about this at the "other place" but I thought I would get some input here. This is what I have so far:

I bought a Yamaha Waverunner 3 for $100. It's a 1990 2 stroke engine.
The guy I bought it from said he had it out on the lake and lost power. He brought it in and took it home where it sat for probably a year.

It was really low on oil but it wasn't totally out. I cranked it up once and it ran rough with lots of smoke. I didn't want to run it for long out of water. The fuel was 2/3 full but it was old fuel.
Fast foward a month later;
Someone told me there should be a hose in the engine compartment to run it out of the water. I found that and put a hose on it. I took the main fuel line going to the carburetor and stuck it in a jar of fresh 92 octane fuel. It sounded like it wanted to start but it didn't. There was a lot of smoke coming from the carburetor. When I cranked it and hit the throttle it made a kind of wet sucking sound and still didn't start.
I think I can get it running. probably just needs a carburator rebuild??

Things I know:
-The shaft spins freely with no obstruction. I did clean out some fishing line.
-The plugs are good and getting spark.
-It's taking fuel, the level in the test jar went down.
-It seems like it's getting good compression. I didn't test it with a gauge but I cranked it with my thumb over the plug hole and it blew out pretty forcefully.

And the latest:

I got a carburetor rebuild kit $54 and that went well.

The problem is I was doing a test run before I decided to pull the carburetor and hooked up a hose to the engine before starting. Now i hear that your supposed to start the engine first then put the water on. The guy at the shop said it wouldn't start because the spark plugs were under water??

So I go out and pull the plugs and fire it up but didn't see any water. The guy said to do this to get the water out??
Anyway I put my finger over plug #1 while cranking and it pushed out very forcefully. Did the same to #2 and it was very weak. So now I'm thinking that water bit may have been a costly mistake.

I'm going to pull the cylinder head off and check clearance. I don't mind replacing the rings but no way am I tearing into the bottom end.

Yeah I know water doesn't compress but I figured there would have to be some kind of safety device. Reed valve maybe? helical spring on the head? It's a positive displacement motor running on the water for heaven sake!

I've been looking over yamaha's website, which is totally awesome btw. They have every part listed with a diagram of every system on the jetski. Didn't see a hosebib in any diagrams.

The saga continues....

Danny