NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

[vintageboater]

I just acquired these (2) jet skis and neither of them run. Both are just alike and the same year, but came from different owners. I have no expierence with anything boating related. I only have expierence in small engines (lawn mowers, weed eaters, etc.) and small gasoline IH Farmall Tractors (I restore them). I was told that the particular ski pictured below would run.....I put a new battery on it, 1 short spray of starting fluid, and BAM! It fired right up and I reved it one time and shut it off; I let it run only about 3-4 seconds. Well.....now I know it will run. Today I went back out there to show dad and to check to the compression on the cylinders. I checked compression first (120 psi on each). This time I poured some gas in the carb, and nothing. Not even a sputter. This evening we went back and checked to see if there was fire getting to plugs (which are brand new). We didn't notice any fire when we grounded a spare wire inside the ski's plug wire and stuck the other end of the spare wire to the engine. I hooked back up the 2 plug wires to the plugs and hit the starter.......BAM! It fired over and started but didn't stay running and died quickly (I'm assuming because I didn't have any gas in the carb since the morning. I wonder what the problem is and why it comes and goes? I jumped the kill switch at the harness plug and it didn't affect anything. I also located a box of some sort that the plug wires, kill swtich wires, and others run inside; and unbolted it but there isn't much room to move it around and nowhere to unhook the wires. What is that? Is that the problem, or could it be the carburetor? Pictures are attached!

 

[JDusza]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

Welcome to the forum.
I cut my teeth on outboards and have limited experience with wave runners, however, if you do what you say you do, you shall have no trouble working on one of these machines. It's all the same; compression, spark, fuel.
I wouldn't go digging into wire harness yet. The ignition test you performed sounds faulted. One would not see any spark if one attached a wire from plug lead to engine ground. That is shorting out the ignition. That's besides the point because now, you know you have ignition and the machine does want to run. I wouldn't go deeper into ignition, yet.
Fuel hasn't been mentioned with the exception of starting fluid and premix into the carbs. The two times running you mention have been with forced fuel. It seems to me that you are not getting fuel into the carburetors reliably, if at all. What's the state of the fuel tank and lines? All clean, flushed out and refilled?
Stay away from the ignition for now. Find out why you are not getting fuel into the carbs. With fuel in the carbs, you know it will run.
J

 

[vintageboater]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

I ordered a service manual on CD for the waverunner. It tell you what to test on the electrical system to tell what is faulty; however from looking at the "box" on the side of the waverunner, I don't know where to start. It doesn't show a picture or tell you how to test it. All I see is a black box on the side of the engine compartment with wires coming out of the bottom of it. There isn't a harness plug or anything, so there is limited movement of the box once unbolted from the side of the waverunner.

Hopefully someone on here can guide me on how to go about checking the electrical system and fixing my problems.

 

[jbjennings]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

JDuszca gave you excellent instructions. You should follow them. You're getting spark; you need fuel. Clean the fuel system and clean the carbs. Make sure the fuel shut off valve is letting fuel get to the carb and clean the fuel filter.

 

[vintageboater]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

JDuszca gave you excellent instructions. You should follow them. You're getting spark; you need fuel. Clean the fuel system and clean the carbs. Make sure the fuel shut off valve is letting fuel get to the carb and clean the fuel filter.

I understand what he is saying, BUT I went back a couple hours later and tried starting again with the fuel or starting fluid in the carb, and nothing! I am confused as if I am in fact getting spark.

 

[jbjennings]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

Go to autozone and get a spark testerj for about $6. It will have an adjustable air gap and will plug into the spark plug boot on one end, and clip on the end of the spark plug or ground source on the other. Your spark needs to jump a 1/4 inch air gap with a blue spark. ANy less and your motor will either not run, or not be able to handle pushing spark at higher rpms and it won't have any power.
After you've verified consistent and reliable spark, then get into the fuel system.
Hope this helps,
JBJ

 

[vintageboater]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

Thanks so much!

Go to autozone and get a spark testerj for about $6. It will have an adjustable air gap and will plug into the spark plug boot on one end, and clip on the end of the spark plug or ground source on the other. Your spark needs to jump a 1/4 inch air gap with a blue spark. ANy less and your motor will either not run, or not be able to handle pushing spark at higher rpms and it won't have any power.
After you've verified consistent and reliable spark, then get into the fuel system.
Hope this helps,
JBJ

Thanks so much! I will check it out! I didn't know they made such a tester. We have always just removed the coil wire and grounded it to see if it was firing, but this rig doesn't have that, so I'm guessing the tester is what is needed! THASNK

 

[vintageboater]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

Ok. I am attaching my test results from last night. I will also attach the actual print out of the service manual that I used as my guideline. It was not very detailed as to how to test everything, but told alot. I made some schematics on HOW I tested it, including my results. The reason I did that is because I want you guys to review it and tell me if I did everything correctly, tell me if my results look appropriate, and tell me what I might have done wrong or need to do in addition.

I will also attach a .pdf file of the entire Electrical System Section of my service manual although I didn't perform the tests on the other pages in this attachment. I am posting this ONLY if there is something there you guys think I might have done wrong, not checked, or a detail I might have missed.

Again, I'm VERY NEW to this stuff; so everyones input is GREATLY APPRECIATED!!! Thank you all so much thus far!

 

[vintageboater]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

Service Manual Test Procedures I performed.....

 

[vintageboater]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

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My Test Results of Performed Tests as previously posted

 

[vintageboater]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

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My Test Results of Performed Tests as previously posted
View attachment 157695View attachment 157696View attachment 157697View attachment 157698View attachment 157699

Just checking to see if anyone has any input.

I would like to state that I did check the fuel system, and I am in fact getting good fuel flow to the carburetor with new fuel in the tanks.

 

[Dyl]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

I have a similar problem, I have mine which is same year and everything, but I get mine to run as long as I play with the choke and throttle at low speeds around idle speed but once I go faster i keep the choke turned off and as long as I stay full throttle I do t need to play with the choke and she runs fun until I slow back done them I have to play with the choke again.

 

[vintageboater]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

Guys.....just getting around to work on the ski this year and really hope to get it going for this season. I have been busy this past winter and the last few months restoring an antique tractor, and now that it is out of the way I hope to get the ski going.

As you can see from my previous posts last summer, I did have good fuel flow to the carb and that seems to be fine. As far as the spark, I have no clue what is going on. I ran the tests per the manual but don't understand how to interpret them. Just need a little guidance on how to interpret the results of the test (per the manual), or tell me another good way to check for faulty parts causing no spark, etc., etc. I really hate to buy a used CDI when that isn't the part and not be able to return it and get my $200 plus back. lol

 

[ahickman]

Re: NEW OWNER NEEDS HELP - 1988 Yamaha Waverunner WRG500

I am working on a 88 WR500 right now. Highly recommend you tear down the carb and rebuild it. Mine was full of white powder caked in every corner. Just curious as to which manual/CD you purchased?