Intermitted spark How do you test a magneto?

[bigfoot_69]

I've got this 1994 GTS Sea Doo that will start one day and not the next. I've replaced the Multi-fuction mod. with no fix. Looking to find a way to test magneto and coil. Can't find anyone that sells the ignition tester sea doo suggests. P/N 295 000 008. Can I test with a ohm meter? What wires / reading?

[ June 24, 2003, 09:15 PM: Message edited by: bigfoot_69 ]

[Technical Support]

What exactly does it do when you try?

[bigfoot_69]

We press the starter button and if it starts it runs great. If it don't start right up we test for spark and there is none. We have had it in the shop 4 times for this problem. If it fails to start we can run a battery dead trying all week to start it on vacation. By the time we get it to the shop it starts right up and they tell me there nothing wrong. I take it back to the lake it will run the day we get there but next morning zip no spark. When it runs it runs great.

[ June 24, 2003, 05:49 PM: Message edited by: bigfoot_69 ]

[Colin GSXL]

Is your battery fully charged when it fails to start. Doo's need a well charged battery to get a good spark when cranking.

[bigfoot_69]

Yep New battery charged 48 hrs on the bench. What happens if the temp senor goes bad? Will it shut down the engine? We ran it two summers ago and 100 yards off the dock at 30 mph it just quit. No spark. We been fighting this problem for now our 3rd summer season. We trailer it back to the shop and it starts. They ran it a half a tank of gas in the tank and could not get it to fail. We start it and and go 50 feet and it quits. No spark at the plugs. Most of time it fails to start cold. once warmed up it seem to keep running and starting.

[ June 24, 2003, 08:08 PM: Message edited by: bigfoot_69 ]

[Bill O'Neal]

Lanyard post, start stop switch, rectifier, faulty rev limiter, or just a loose connection somewhere.

The old sea doo's don't have the battery low ignition cut off that the newer ones do.

The heat sensor has no connection to the ignition. Maybe a broken wire in the magneto harness ?

[bigfoot_69]

Thanks Bill for replying. I've been looking for the seadoo ignition tester. Two shops have come back and told me there discontinued. So how do you test a magneto on a 94 GTS. The Landard is the old type that just holds the button down, Got 3 new ones cause the cords rotted on the old ones. Stop switch works, Start switch works, the rev limiter was replaced, 280 bucks to get no fix. all that left is the magneto, coil, wires. I would think not the rectfier as it uses a different coil in the magneto, i think its use is to charge the battery.

Yellow/black to yellow battery charge coil measures .5 ohm (spec .05 - .6). red/black to black mag gen coil measures 61.1 ohm (spec 40-76) ignition coil primary input to ground Open circuit, No ohms, not even a short. Well time to order a coil. Stay tuned.

[ June 24, 2003, 10:42 PM: Message edited by: bigfoot_69 ]

[Michael73]

I had a similar problem with my Kwaka 550, everything tested perfectly with the multimeter, but it was still breaking down, ended up being the Ignition Coil. As I said it tested perfect underload on a bench, but in the hull it played up.

Goodluck, hope this helps.

Its Bloody Freezing in Australia. My Doo is frozen.

[Bill O'Neal]

Lanyard switches go bad. I didn't mean to buy a new lanyard cord.
Sometimes in older skis, I can adjust the lanyard post to sit higher, so the lanyard can push the button further down and keep it from losing contact, other times, I just have to replace the lanyard post.

I have one of those ignition testers that you so desire. We never use it.

Funny thing about the Sea Doo repair manuals. They give you all the specs for the testing, then they say " when all else fails and everything checks out ok with the testing, start swapping parts until you find the problem" or something to that effect.

Coils rarely fail. Stators rarely fail, unless they get damaged from rusty flywheels that are so bad that the magnets drag on the stators, or some foriegn object like a gear tooth is stuck into them, shorting them out.

[bigfoot_69]

Thanks Bill about the switch and not the cap. I was thinking more about they get old and loose their grip. I tested the switch and its ok, I was just stating that I had new landards as well. I think what happened is this and why I'm comfortable with the coil replacement. This might be a tip for others to check. In inspection of the coil I found that after years of pulling off the spark plug caps to repalce plugs the cables have slowly pulled out of the cap. This causes a large gap from the end of the cable and the contact inside the plug cap. At some point the gap got large enough to pull out of the cap all together. But before that happened that arc found a shorter path to ground inside the coil. Bench testing the coil with an ohm meter I get no readings in both the primary and secondary leads. The ground leads of both coils are open. I think a new coil will fix the problem. Thanks one and all for your replies and helpful hits. I just wish there was a better manual more focused on troubleshooting then the Sea Doo manuals.

[ June 25, 2003, 12:39 PM: Message edited by: bigfoot_69 ]