Personal Water Craft Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
Hi everyone, new to PWCs and new to the forum :tango_face_smile:

So I recently picked up my first PWCs, both Yamahas. A 1993 Waverunner III and a 1993 Waverunner VXR. The seller showed me that they start or I wouldn't have bought them, but naturally when I got them home neither one started.

The Waverunner III was a pretty easy fix (fuel selector valve was worn out so you have to put it in exactly the right spot or fuel won't go through) and I took it out a couple weekends ago with no problems. But the VXR has me stumped.

The starter motor turns over so I assumed it needed a carb rebuild, because everything needs a carb rebuild, but I rebuilt it last night and still won't start. I checked spark plugs today and I'm getting a good spark, but I have oil all over the plug threads. The oil tank is pretty full, how full is too full? Could that be what's causing the problem?

Is there anything else I should be looking for? I have the service manual, but it's not super helpful for troubleshooting a non-starting jetski.
 

·
Registered
Joined
·
1,357 Posts
Hi everyone, new to PWCs and new to the forum


So I recently picked up my first PWCs, both Yamahas. A 1993 Waverunner III and a 1993 Waverunner VXR. The seller showed me that they start or I wouldn't have bought them, but naturally when I got them home neither one started.

The Waverunner III was a pretty easy fix (fuel selector valve was worn out so you have to put it in exactly the right spot or fuel won't go through) and I took it out a couple weekends ago with no problems. But the VXR has me stumped.

The starter motor turns over so I assumed it needed a carb rebuild, because everything needs a carb rebuild, but I rebuilt it last night and still won't start. I checked spark plugs today and I'm getting a good spark, but I have oil all over the plug threads. The oil tank is pretty full, how full is too full? Could that be what's causing the problem?

Is there anything else I should be looking for? I have the service manual, but it's not super helpful for troubleshooting a non-starting jetski.
How do vigilante397. Welcome to the forum.

Oil on the plug threads are not so much a concern, so long as the electrodes aren't all wet with oil. If your getting good spark acrosed them there good.

Have you checked your compression? What's psi at?
What did you use for a carb rebuild kit? Mikuni or aftermarket.
Are you getting fuel to carb and motor?

I have a 93&94 vxr pro same as yours but 700 motor. Love them both. A blast to ride.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #3
How do vigilante397. Welcome to the forum.

Oil on the plug threads are not so much a concern, so long as the electrodes aren't all wet with oil. If your getting good spark acrosed them there good.

Have you checked your compression? What's psi at?
What did you use for a carb rebuild kit? Mikuni or aftermarket.
Are you getting fuel to carb and motor?

I have a 93&94 vxr pro same as yours but 700 motor. Love them both. A blast to ride.
Thanks :tango_face_smile:

I don't have a compression gauge, but it's on my list of things to pick up now that I'm getting into this.
The rebuild kit was listed as "AFTERMARKET MIKUNI SBN CARBURETOR REBUILD KIT".

I have been thinking about the fuel, especially since that was the problem with my other ski. What's the best way to check that?
 

·
Registered
Joined
·
1,357 Posts
Ok compression testers can be rented cheap from most auto parts stores.

For fuel if you have a weed eater try splashing a tablespoon of fuel oil mix into carb and try starting. If it starts it's a fuel issue. If no weed eater fuel mix a tablespoon and 4 or 5 drops of oil in a small container. Enough to lube cyl.

For carb builds use Mikuni Kits only. A bit more money but a lot less trouble. Most aftermarket kits just don't cut it and in the end the carbs have to be redone. You may have to redo carbs with true Mikuni Kits.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #5
It's a fuel issue! After a month of messing with it it's nice to finally have a definitive answer on that. I did what you suggested, mixed a little bit of fuel and oil and shot it into the carb, and it started right up!

I'm planning to go through the fuel system section of the service manual, but are there any common problem places you would suggest I check first? I've heard the fuel filter can be one, so I'll definitely be checking there.
 

·
Read Only
Joined
·
5,059 Posts
Replace the fuel lines and filter, do a carb rebuild. Reuse the needle, seat, and spring. Get those oil injection lines replaced on both asap. Nice thing with those (if I remember) is they used a check valve down by the injection pump, so pre-primming the line is super easy with a large 50cc syringe.
Where exactly are you located ? I have family in the Antelope Valley.
 

·
Registered
Joined
·
1,357 Posts
Rods, pretty much has it covered. The only thing I'll add is sometimes the fuel selection valve clogs up. Or the o rings fail and give you an air leak so carb can't draw fuel.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #8
Replace the fuel lines and filter, do a carb rebuild. Reuse the needle, seat, and spring. Get those oil injection lines replaced on both asap. Nice thing with those (if I remember) is they used a check valve down by the injection pump, so pre-primming the line is super easy with a large 50cc syringe.
Where exactly are you located ? I have family in the Antelope Valley.
So I did a little more digging last night, and the fuel filter was in backwards. I flipped it around for now, as I understand they're directional, but I won't get to try it out until after work today (skis are parked outside my kid's window and I really only get to work on them after the kids are asleep). I've still ordered new fuel lines and a new filter, they should be here tomorrow. I just did a carb rebuild, but I used an aftermarket kit so I'm hoping it's still okay. I'll get new oil lines in as well. And as to Dave's suggestion, the fuel selection valve was worn out and wasn't latching in position so it could potentially wiggle itself closed, so I already replaced that.

I'm actually very close to Antelope Valley, I live in Ridgecrest, a short drive away. I actually bought the skis from someone in Palmdale. Small world :tango_face_smile:
 
1 - 8 of 8 Posts
Top