texamwalker
New Member
Any one out there educated on the Dess system or the electronic igniton system on a 98 sportster?
98 Sportster Dess or Mpem Problem. Need Diagnostic Help
- Thread starter texamwalker
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You have the 717's or 787's? If you have the 717's the MPEM is basicly just a security system with a standard CDI ignition. The 787 the MPEMs contol much more sutff just like a cars ECM you usually need a tool to read the MPEMs and adjust the settings in them. You can get codes and errors out of the them just like a car unless you have 717's. You can do nothing but change the hours, name, and add/remove keys to the DESS with the 717's. I know since I bought the aftermarket tool to read the MPEM and my Sportster 1800 has the 717's.
texamwalker
New Member
this sportster is the small 14' boat with the single two stroke rotax engine...130 hp i believe. i need some help on what to check to tell me if its the key, the dess post, or the mpem.. like get me as far as possible with a simple volt/ohmm meter to narrow down the problem
So you have the 951 engine in your boat? That one is the 130HP. Do you get the 2 beeps when you connect the key to DESS? or any beeps when you connect to the DESS? Also what happens when you try to start the boat?
There is a document here on this site that tells you what the beeps mean and you can get the manual for the boat from here also being a premium memeber. You will need the manual to get the specs you need to check the DESS port and MPEM but you need to hook up to the MPEM to make 100% sure or make a educated guess by process of elminination. You can only do so much testing with a meter to the MPEM without the scanning toold. You can also just take the boat to the dealer to have them hook up to the MPEM if you want to know right away.
There is a document here on this site that tells you what the beeps mean and you can get the manual for the boat from here also being a premium memeber. You will need the manual to get the specs you need to check the DESS port and MPEM but you need to hook up to the MPEM to make 100% sure or make a educated guess by process of elminination. You can only do so much testing with a meter to the MPEM without the scanning toold. You can also just take the boat to the dealer to have them hook up to the MPEM if you want to know right away.
Dr Honda
Well-Known Member
He has a single 720 engine.
Texas: Try asking a question. You've made 2 posts in the this thread, and neither of them have a question. If you tell us what the problem is, and what you are trying to accomplish... you may get the help you are looking for.
texamwalker
New Member
Dealerships are not the best option in my case. ive taken it to a few and talked to countless on the phone and everyone acts like im wasting my time and they arent gonna be able to help me because that boat is so outdated that they wont be able to work on it.. the closest one that even gave me a little hope was about 200 miles away and i dont feel like pulling it that far just to find out that they cant help me so i decided to try and take it on myself the best i can. i know just enough about electronic ignition to get me in trouble. i can fix ignition systems that have common distributor/points in my sleep but this computer/dess/mpem stuff is gonna give my grey hair way to early in life.
Ill try to describe what the boat is doing. Its very random so i apologize but its the best i can describe.
Three days ago boat ran fine. Put key on post, got two short meduium volume beeps, hit starter button and motor fired and ran
Next day went to take it out. Put key on post, got two short medium voulume beeps, hit starter button and motor turned over well but didnt fire. Let off stater button and tried again and got nothing. No cranking at all.
checked all fuses, good. Checked all wiring connections, good. Jumped starter solenoid with screwdriver, mover turns over just fine but no fire. Put key on post and still got the two short medium volume beeps.. it did this with both keys i have. Then i started to get one long beep if i held the starter switch down for more than a second.
I decided to drag the boat back home and get out my volt/ohm meter and do some checking.
When i got home and was gonna get started on it, i put the key on and got nothing, not even the beeps now. i know the battery and battery connections are good cuz the bilge pump, blower and lights would still come on and the starter would still turn the boat over when the solenoid was jumped with a screwdriver.
i figured the vibration from the ride home might of changed something.
Later that day i went back to work on it and when i put either key on, i heard the faintest single tone from the bell. It was so quiet you can barely hear it but its there.
This is what ive checked so far.
The black wire with a yellow stripe is hot going to the post.
The starter switch ohms out and shows to be good.
The red/yellow wire is hot to the starter switch, when you push the button, i get juice on that wire goin into the left side of the mpem but nothing coming out the other side of the box so therefore no juice to the relay on the starter solenoid.
All fuses show to be good.
I want to know what i should attack next with my volt meter to narrow the problem down to find out where the problem lies.
Ill try to describe what the boat is doing. Its very random so i apologize but its the best i can describe.
Three days ago boat ran fine. Put key on post, got two short meduium volume beeps, hit starter button and motor fired and ran
Next day went to take it out. Put key on post, got two short medium voulume beeps, hit starter button and motor turned over well but didnt fire. Let off stater button and tried again and got nothing. No cranking at all.
checked all fuses, good. Checked all wiring connections, good. Jumped starter solenoid with screwdriver, mover turns over just fine but no fire. Put key on post and still got the two short medium volume beeps.. it did this with both keys i have. Then i started to get one long beep if i held the starter switch down for more than a second.
I decided to drag the boat back home and get out my volt/ohm meter and do some checking.
When i got home and was gonna get started on it, i put the key on and got nothing, not even the beeps now. i know the battery and battery connections are good cuz the bilge pump, blower and lights would still come on and the starter would still turn the boat over when the solenoid was jumped with a screwdriver.
i figured the vibration from the ride home might of changed something.
Later that day i went back to work on it and when i put either key on, i heard the faintest single tone from the bell. It was so quiet you can barely hear it but its there.
This is what ive checked so far.
The black wire with a yellow stripe is hot going to the post.
The starter switch ohms out and shows to be good.
The red/yellow wire is hot to the starter switch, when you push the button, i get juice on that wire goin into the left side of the mpem but nothing coming out the other side of the box so therefore no juice to the relay on the starter solenoid.
All fuses show to be good.
I want to know what i should attack next with my volt meter to narrow the problem down to find out where the problem lies.
Personally I would go back and start with the basics. Check and clean the grounds, especially the neg. battery cable at the battery, at the engine ground and the cable itself. I would also have the battery load tested, just because the accessories work doesn't mean there's enough power to start the boat.
Lou
Lou
texamwalker
New Member
correct me if im wrong but if i can jump the solenoind with a screwriver and the motor turns over like crazy, couldnt you assume that the battery is hot and conections going to the starter are good? Does the mpem have a hot and ground wire that actually go to the battery to power itself that can be checked with a volt meter?
texamwalker
New Member
i guess what im looking for is like someone tell me check this wire for juice or for ground and tell me in the "train" fashion.. Like starting at the battery and goin all the way to the relay on the starter solenoid. i know its more complicated than that, i just want someone to be able to "dumb" it down enough to get on my level if that makes sense
texamwalker
New Member
Yes, that is correct.
Sorry for the long question. Just trying to give the best info i can to help
Do you have the manual? It goes through with pictures on how to test the items and what to test in order. Pretty much the Unoffical MPEM guide is highlight of the manual in what to test. http://www.seadooforum.com/showthread.php?45694-Unofficial-587-657-717-Mpem-troubleshooting-guide.
texamwalker
New Member
no i do not have any sort of manual. is that a link to a free maunal i can download?
texamwalker
New Member
and i read the post youre reffering to and i know it sounds bad but it seems to still be very broad and surprisingly still difficult to understand. where can i get a step by step, wire color by wire color diagnostic sequence
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