96 yamaha ra700bu(waveraider)

[Danmaster02]

I just bought this ski but im havng troubles getting it diagnosed. the person I bought it from say it had no spark. I have been told to test the resistance in the coils, magnito, and the CDI. Does anyone know what range the ohms should be? the shop by my house wants $300 to test it and that sound rediculous to me. Any help would be great! thanks.:redface:

 

[The Penguin]

Re: 96 yamaha ra700bu(waveraider)

1. is the battery good? Does the engine turn over?

2. pull the boots off the plug wires and look at the electrode inside. If you can't see electrode, trim the wire back until you can see it. Re-install boots. You may have to buy some aftermarket boots to place on the wires. MSD makes good ones. test.

3. if still no spark, remove and open the e-box. check the CDI, ignition coil (bad wires are most common coil problem... www.jetskisolutions.com can install new wires) and check the solenoid.

 

[Danmaster02]

Re: 96 yamaha ra700bu(waveraider)

I have spark,(i checked again tonight) engine turns, but no combustion. not even a little. maybe not enough spark? Im going to buy some new plugs in the morning. Anyone know the appropriate gap? If the CDI is wrong or bad, would it even spark? to answer your question: The battery is new, the wiring all "looks" brand new. any input is appreciated.

 

[bigdaddypt]

Re: 96 yamaha ra700bu(waveraider)

there are 3 things that your engine needs to run...spark, compression, and fuel. you're saying you have spark...are you sure about the compression and fuel? It'll take 5 minutes to do and will rule out the other two, but do a compression check. after that, take the spark plugs out, pour about a teaspoon of fuel in each cylinder, put the plugs back in and connect the wires.

If the ski fires right up, then it's a fuel problem, if your compression is low, then it's obviously a compression problem. If it's a neither...do what the penguin suggested with clipping the plug wires and reattaching the boots. Gap the plugs at .20.

 

[The Penguin]

Re: 96 yamaha ra700bu(waveraider)

0.2 what?

factory service manual has gap at 0.6mm - 0.7mm or 0.024 - 0.028 inches.

 

[The Penguin]

Re: 96 yamaha ra700bu(waveraider)

here's another thing to check -

start/stop switches are known for going out on Yamahas. find the e-box. The s/s switch leads should come out the side of the box...red/brown pair for start, white/black pair for stop.

a few inches outside of the box, each pair of wires will go to a connector. unplug the white/black pair and try starting your ski. This disables the stop button on your ski, so you'll have to have another method of stopping the motor if it does decide to fire up. (choking it off or flooding if you have a primer system is the best way).

try to start your ski with the white/black connector unplugged. If the ski starts, your s/s switch is bad and needs to be cleaned, rebuilt, or replaced.

 

[bigdaddypt]

Re: 96 yamaha ra700bu(waveraider)

I meant .02 inches.

 

[Danmaster02]

Re: 96 yamaha ra700bu(waveraider)

thank you all for the replys. I will do what was suggested tonight and see if it works. keep your fingers crossed.:redface:

 

[Danmaster02]

Re: 96 yamaha ra700bu(waveraider)

No luck with my pwc. im thinking that this CDI unit is wrong. it is made by mitsubishi part number is 62t-00, F8T13175 I found that part number for wave runners but does it make a difference?

 

[markmecury]

Re: 96 yamaha ra700bu(waveraider)

no spark stator is bad

 

[bigdaddypt]

Re: 96 yamaha ra700bu(waveraider)

could be the stator, could be the CDI, could be the coil.

 

[Danmaster02]

Re: 96 yamaha ra700bu(waveraider)

I do have Spark When i take the plugs out and test them. But i don't have any combustion and or wont run??? If you could answer these questions:
1: How do you test for compression?
2: can it be the wrong CDI unit? (timing for the spark may be off???)
3: What should the ohms for the resistance on the: Coils, CDI, Stator, Starter relay, Be?
last but not least...
4: Could it be that I'm not giving it enough chance to start? it hasn't run for a year at least.

 

[JPS6881]

Re: 96 yamaha ra700bu(waveraider)

Drain the tank if the fuel is old. As previously mentioned, pour about a tablespoon worth of of fuel (2 cycle mix, NOT raw gas) into each cylinder, tighten plugs/wires and see if it fires. If you are getting spark, it should at least run for a couple seconds. Repeat the above a few times with the choke on, and see if you can get it running with fresh fuel. My guess is that you may have carb issues if it has been sitting.
( A compression tester will screw into the spark plug hole, spin the engine a few times and the dial will give you a reading. A parts place like NAPA or Autozone may lend you one for a small fee.)

 

[The Penguin]

Re: 96 yamaha ra700bu(waveraider)

on the CDI question - all the 2cyl 650/701/760 CDI's are basically interchangeable. the wiring is all in the same configuration - the difference between them is in the internal timing curve.

you can switch from one CDI to another without any problems.

somewhere at home I have a document on testing the stator, I'll see if I can find it and post it tomorrow.

 

[Danmaster02]

Re: 96 yamaha ra700bu(waveraider)

I found the problem i guess. Compression. port 1 was 50-55 psi and the second was 60psi. i was told that it should be around 118 psi. is this accurate? if it is you think i should try to fix it or just buy a new engine?

 

[The Penguin]

Re: 96 yamaha ra700bu(waveraider)

that depends - are you willing and able to remove your motor and rebuild it?

if not - buy a new motor.

If you are, get a manual and get started. It's not very hard.

I'd almost guess that all you are going to need is a light hone job, and replace the rings.

 

[Danmaster02]

Re: 96 yamaha ra700bu(waveraider)

anyone know where i can buy a new engine? about how much they should cost?

 

[The Penguin]

Re: 96 yamaha ra700bu(waveraider)

if you want to go cheap, get an SBT motor, but get the "gold" package for the longer warranty.

you need to find out WHY the previous motor went out before just installing a new one.