Help! Ski ran fine and now it does not start!

[Lake_Life]

Hello, this is my first post on the X and I do alot of research here to build my superjet.. So long story short, I have a 91 SN with a 62t engine. Got it idling perfect and revving with no problem. I just put it in my lake to do a test run and ran perfect! I did a few laps and came back to my house to adjust my steering cable. After that I went to start it and it just cranked over and over.

I checked spark at both plugs, and it's good, checked fuel at carbs, it's good and checked compression which are at 150psi each cylinder. I put gas in the carb to see if it needed to start but nothing. I'm stumped! What do I check next? Thanks!!

 

[Fx1 Love/SJ Love AZ]

If it doesn't fire with fuel strait down the throat typically it's electrical. Check the spark first you will see the current arc if it has good spark. If not start with the coil, hopefully it's not the cdi. Also the spark plugs being incorrectly gapped can do that. My buddy revved his 650 a ton after riding and it must have knocked the plugs just that tad because it wouldn't fire and then we re gapped and it fire right up no problem. Goodluck hopefully more experience people chime in but I know the feeling of your ski not running. Can't relax till you get her fixed haha stay up.

 

[Dmac80sc]

If you have spark and fuel it should start up. Any chance the battery is low and just isn't getting enough cranking power? I saw a trick once when my buddy had spark and fuel, but won't crank. He closed the gap on the plugs a little and it cranked. It turned out to be a weak stator not giving it enough juice.

 

[Fx1 Love/SJ Love AZ]

Yes true that if you open up the flywheel core and water pours out you have a problem. So you should check that since its easy to pop it off and put it back on. Squares take on a ton of water so it could be likely. I've destroyed 2 Bendix with my square and none on my FX.

 

[Dmac80sc]

Yes true that if you open up the flywheel core and water pours out you have a problem. So you should check that since its easy to pop it off and put it back on. Squares take on a ton of water so it could be likely. I've destroyed 2 Bendix with my square and none on my FX.

If you are getting water in your motor something isn't sealed right. Might be where your starter is (need to grease it or 1211 it) or where your flywheel cover is.

 

[Lake_Life]

Thanks guys for your input, so far i have checked the spark plug gap which was at .025" which is in spec and i closed it a little bit to .020" and still nothing. I have a good known coil and swapped that, still nothing.. I ohm tested the stator and its within spec. I realized when i ohm tested the cdi box, all I got was open readings through out each wire. Could a bad CDI cause a no start issue even if your still getting spark?

 

[SKI BONEZ]

The cdi can cause it and is a easy swap if u have another to test it with. The cdi and start/stop switch are the 2 most common things to go out on a yamaha. I have a grip of bad cdi.s I've replaced hanging on my garage wall to remind me...lol I always start there first...

skibonez
9285428519

 

[Fx1 Love/SJ Love AZ]

you can find a cdi alone from a member here in the forsale for as low as 30-40 bucks. new they are an arm and a leg but im sure someone on the forum will have a cdi they can part with for cheap. i may even have an extra haha. it was my starter that was causing stator water problems, i put it in dry because i had never done it before, but re installed with grase and not a single problem since. with the cdi, its easy to do if you have the one your replacing it with with you so you can disconnect and reconnect wires one at a time, i used my ipod to take a pic of the wires to use as a diagram. help from someone who has done it before is really the golden ticket to getting it done right and timely.

 

[XJCrawler]

Thanks guys for your input, so far i have checked the spark plug gap which was at .025" which is in spec and i closed it a little bit to .020" and still nothing. I have a good known coil and swapped that, still nothing.. I ohm tested the stator and its within spec. I realized when i ohm tested the cdi box, all I got was open readings through out each wire. Could a bad CDI cause a no start issue even if your still getting spark?

How long are you getting spark for? Is it running out after a few seconds?

 

[Lake_Life]

It keeps sparking if u keep it cranking but I noticed that the spark is a white color and seems to be weak. I threw gas into the carb and cylinder and doesn't start at all. I was going to swap electronics but I don't have an extra 62t cdi. I swapped my engine down to a 650 I have laying around here just to ride this weekend that I have as a spare. Thank you guys for your input, I appreciate it

 

[b.lee]

If you are getting water in your motor something isn't sealed right. Might be where your starter is (need to grease it or 1211 it) or where your flywheel cover is.

Agreed.
Or base gasket / head gasket... im guessing head gasket.
If it runs good otherwise, water is probably seeping in somewhere once you stop and take a break from riding