98 xp blowing fuse

[jbssc]

My son was riding today (40-50 mph) and the ski died. I found that the 15 amp fuse in the MPEM was blown. I replaced the fuse and the ski started right up. It will idle just fine but when you give it a little throttle the fuse (15 amp) in the rear electrical box blows. I reviewed the posts in the forums and will try unplugging the VTS tomorrow. I tried chasing the problem through the electrical diagrams in the shop manual but it a bit complicated. I'm hoping that someone out there has dealt with the same problem. Any help to point me in the right direction would sure be appreciated.

[1fastski.com]

Re: 98 xp blowing fuse

if the VTS dont solve it test your stator any short in there will blow fuses { bendex theeth break and short out the stator now and then .

[cover8]

Re: 98 xp blowing fuse

Although, i am new on this forum and to PWCs I have been doing alot of electrical troubleshooting as i was also blowing the same fuses (99xpl).


Remove the connections to the battery and ohm them. Is your battery draining? When I checked for continuity in the battery connections I got 0.8ohm :( and realized right away I had a major short in the boat and was draining batteries within minutes.

Next, I removed the electrical connector to the front cover (to the stator/magneto) and had not continuity in the ohm meter. This indicated to me that I had something very wrong with the stator/magneto. I removed the front cover and had a burned/discolored stator. I like to wavejump and maybe shocked my magneto.

[1fastski.com]

Re: 98 xp blowing fuse

loose or dirty grounds will burn up stators , and couse many other elect problems . also check and keep them clean . also the bendex on the 800 and 951 tends to leave a lot of shavings flying around they dont help .

[jbssc]

Re: 98 xp blowing fuse

How difficult a job is it to replace the stator?

[1fastski.com]

Re: 98 xp blowing fuse

easy in the 98xp just remove the front cover amd engine mount put a block under the engine . the stator in in the front cover .

[jbssc]

Re: 98 xp blowing fuse

Well it wasn't the VTS. The next best possibility seems to be the stator.

[Bill O'Neal2]

Re: 98 xp blowing fuse

Yes, being that the 7.5 amp fuse is linked to the VTS and the 15 amp fuse is fusing the charging system (stator), I suspect you will find your problem there.

[jbssc]

Re: 98 xp blowing fuse

I pulled the front cover, but I don't see anything too remarkable. There are some fine shavings in the case. There are no broken teeth or any large fragments attached to the stator. It doesn't look burned or discolored in any way. Would the small fragments, as the engine accelerates, cause a short? Is it possible that cleaning out the case will solve the problem? Again, the engine cranks OK. It's when you hit the gas that the fuse blows. Does centrifical force play a part in this problem? I did find the testing procedure for the stator in the shop manual and will check that out next.

[cover8]

Re: 98 xp blowing fuse

Did you use an ohm meter to check for continuity between your positive and negative connections to the battery? If you are getting continuity than you have a grounding problem. In my case, the reading at the terminal was 0.8ohms with the grey connector terminated to the front cover. To rule out the stator, you remove the grey clip to the front cover and ohm the battery terminals again....this is the quickest way i know to determine the status of the stator.

Tonight, I replaced my stator with a brand new one...and now with the grey clip connected, I get "1" (discontinuous) on the ohm meter and then check voltage with ski running and got 14.10 volts :)

So a new stator was the answer for me.

[Bill O'Neal2]

Re: 98 xp blowing fuse

It blows the fuse when you give it throttle?

You said "the engine cranks ok". Does that mean it starts and runs, then blows the fuse when you add throttle?

In that instance, I'd be leaning towards the rectifier built into the mpem as a possibility of your problem.

The rectifier/regulator has two jobs, first the rectifier converts the AC power that is generated by the charging coils on the magneto to DC power, which is then regulated to between 13VDC and 15 VDC and sent to the battery. If the rectifier fails, it sends AC power through the syatem and that will blow a 15 amp fuse on the MPEM.

Your next move is to detirmine wether or not the problem is the stator assembly or the MPEM that is causing your 15 amp fuse to blow. Both are expensive parts, so do not buy the wrong part, as neither are returnable.

The only other thing that comes to mind is the TPS switch in the throttle cable. But, I am not sure that if it were shorted out, it would affect the 15 amp fuse. ?? Anybody know ???

[jbssc]

Re: 98 xp blowing fuse

Bill, I can crank the engine and idle around for "a while". But as soon as I hit the throttle the fuse blows. I looked in the manual for TPS and all I could find was a note indicating that a throttle position switch was no longer necessary for the 947 engine. If I put the meter on the battery terminals while I advance the throttle, would I be able to tell if the regulator is not regulating the current? By the way, thanks for the help. My son like to ride the ski and I like to fix it. It works out well for both of us. Without your help (and others on the site) my part would not be possible.

[Bill O'Neal2]

Re: 98 xp blowing fuse

Yes, place a voltage meter on the battery and get the reading before you start the motor. If possible, start the motor, rev it to 5500 rpm and get the new reading. It should read between 13 and 15 volts. If it reads the same or less than with the engine off, or more than 15 VDC you need an MPEM or a new stator. If you find any metal pieces embedded or stuck to the magneto , stator or pickup, you need a starter drive also, as a tooth will be missing out of it or one of the internal clutch parts has broken in the starter drive and is shorting out the magneto, stator or pickup.

It is a fair amount of work to see the magneto, but you should inspect each piece closely, as if that is your problem ( common on 1998 951 engines) it may save you from buying a very expensive MPEM that you did not need. 1998's are notiourious for breaking starter drives.

[jbssc]

Re: 98 xp blowing fuse

Now I don't know what to think. I pulled the front cover and checked out the stator. The static tests were negative. So I vacuumed out the few shavings that I could see, wiped everthing down, vacuumed out the stator, and put everything back together. I cranked the engine, let it idle, revved it up a few times, and had no failure. I still need to do the dynamic test to make sure its not putting out excessive voltage. Could it be that something was wet and causing a short or that I had a bad ground causing the problem?

[Bill O'Neal2]

Re: 98 xp blowing fuse

It very well could have been a bad connection. Welcome to the world of marine electronics.........