timmyboy76
New Member
i'd remove it from the ski, and charge.
Jump Starting....?
- Thread starter seadoosnipe
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first off, i am new to this forum, so hello all!
second i work on these things all the time , sigh!
third , i have jump started hundreds,yes hundreds of skis with no ill effects!
yes you must NOT have jumping vehicle running !!!!!
voltage is one issuse but amps is the killer!!!
most cars put out over 80 amps from alternator
ski is rated at 30 amps
as for the 5 amp mpem fuse, the mpem can go bad, its a fact of life
like light bulbs,tvs,anything else, it can break!!
simple way to check is to just unplugged everthing else from mpem and then just give it a power and ground, if fuse pops, bad mpem.
as for the 7.5 vts fuse, water intrusion thru vts rod shaft is what i think
the boot at rear of boat becomes brittle and or the metal hose clamps cut into it, allowing water to travel into the sealed!! vts housing were it does its damage, thats why brp started using those little nylon clamps.
and as for mpem only seeing 12 volts while running, hmmmmm????
not sure if that theroy is correct, i would think that it would see battery voltage all the time 12.5 at start up and up too 14.5 at wfo
will have to check this for my self
regulator/rectifiers go bad all the time, but with some help from the owners!
keep you batt terminals clean and tight!!!!
have seen a reg/rect go bad and over charge a ski, this caused the thing to act like the rev limiter was hitting at 4 k rpm, gues it was making the mpem go nutty.
put new one in and it ran great
mud
This post was originally disapproved because I mis-read his comments. I read into his post that he said "to jump start with a running vehicle". Upon reading it again, I see I mis-read his post. The other specific point is the 12 volts at the mpem. This is true but the mpem breaks down the voltage to 5 vdc for use in your instruments.
Sorry for the mis-understanding. Your info is correct and it was my mis-reading it that caused me to un-approve the post.
Thanks for PM'ing me to bring this to my attention. This is how we solve issues when there is reason for debate.
Welcome to the forum and thanks for helping out with members problems.
second i work on these things all the time , sigh!
third , i have jump started hundreds,yes hundreds of skis with no ill effects!
yes you must NOT have jumping vehicle running !!!!!
voltage is one issuse but amps is the killer!!!
most cars put out over 80 amps from alternator
ski is rated at 30 amps
as for the 5 amp mpem fuse, the mpem can go bad, its a fact of life
like light bulbs,tvs,anything else, it can break!!
simple way to check is to just unplugged everthing else from mpem and then just give it a power and ground, if fuse pops, bad mpem.
as for the 7.5 vts fuse, water intrusion thru vts rod shaft is what i think
the boot at rear of boat becomes brittle and or the metal hose clamps cut into it, allowing water to travel into the sealed!! vts housing were it does its damage, thats why brp started using those little nylon clamps.
and as for mpem only seeing 12 volts while running, hmmmmm????
not sure if that theroy is correct, i would think that it would see battery voltage all the time 12.5 at start up and up too 14.5 at wfo
will have to check this for my self
regulator/rectifiers go bad all the time, but with some help from the owners!
keep you batt terminals clean and tight!!!!
have seen a reg/rect go bad and over charge a ski, this caused the thing to act like the rev limiter was hitting at 4 k rpm, gues it was making the mpem go nutty.
put new one in and it ran great
mud
This post was originally disapproved because I mis-read his comments. I read into his post that he said "to jump start with a running vehicle". Upon reading it again, I see I mis-read his post. The other specific point is the 12 volts at the mpem. This is true but the mpem breaks down the voltage to 5 vdc for use in your instruments.
Sorry for the mis-understanding. Your info is correct and it was my mis-reading it that caused me to un-approve the post.
Thanks for PM'ing me to bring this to my attention. This is how we solve issues when there is reason for debate.
Welcome to the forum and thanks for helping out with members problems.
Last edited by a moderator:
greyrider
New Member
would this apply to those portable 'jump starters' that put out mega-amps as well?
when i sunk my ski and had no idea what to do a local guy pulled plugs and went through the hydrolocked procedure. he was a kawasaki guy and jumped mine from a pickup truck while running - it runs fine - guess i got lucky?
when i sunk my ski and had no idea what to do a local guy pulled plugs and went through the hydrolocked procedure. he was a kawasaki guy and jumped mine from a pickup truck while running - it runs fine - guess i got lucky?
jump boxes are fine, the ski will draw the amps from the box that it needs to crank! battery chargers tho, the ones that have a 2amp, 10 amp charge and then a 50 amp start postion is bad, very bad for smaller vehichles, skis, bikes, atv's ect.
as for the previous post with the fried starter, excessive cranking can cook a starter and or starter solenoid.
other things that can lead to this is siezing pump or engine, water in engine.
what happens is someone will think that the battery is low,cause the engine is cranking slow or wont turn at all cause something is stuck.
they grab a boost box and keep cranking on the poor thing,till the starter or solenoid fails, sometimes they will stick and keep on cranking till the battery dies.
mud
as for the previous post with the fried starter, excessive cranking can cook a starter and or starter solenoid.
other things that can lead to this is siezing pump or engine, water in engine.
what happens is someone will think that the battery is low,cause the engine is cranking slow or wont turn at all cause something is stuck.
they grab a boost box and keep cranking on the poor thing,till the starter or solenoid fails, sometimes they will stick and keep on cranking till the battery dies.
mud
Jump starting/close thread....
This thread has been gone over throughly. It was meant as a guideline for jumping your ski, according to BRP's recommendations.
To answer your question Greyrider, no, it does not apply to jump boxes. I don't remember what post number this is, but it's up there. If you go through this entire thread, you will see that it's already stated that the jump boxes are fine. It's also stated that the reason why you do not jump start with a running vehicle is because of the "possibility" (key word, possibility) that you might do permanent damage to your electrical system. When jumping from another vehicle that is running, there charging system is in operation. Which means, the battery is receiving 14 VDC. When you jump start from that system and your engine starts, you have 2 different type charging systems grounding to each other.
This does not mean that your MPEM or rectifier is "going" to blow, it simply means that you are taking a chance. With the price of our MPEM's in the hundreads, if not thousands of dollars, I would think it's better to take preventitve action than it is to take the chance.
As with overheating the starter, melting wires. This is true with anything that has a starter. The starter draws 90% of the batteries CCA (cold cranking amps) during initial startup. The starter is a high torque motor and has to overcome the engines compression to turn the crankshaft over. According to BRP and stated in the shop manual, you should only turn your starter over for 30 second intervals. If your troubleshooting or having a hard time starting, grab your ground wire and see how hot it is. If your battery cable wires are getting hot, shut down the engine and let the system rest.
My advice:...Never, Never, Never jump start a Rotax engine with a battery from a running engine. Did, I say Never?...Just checking. You may be lucky several times but eventually, your going to be paying for a new MPEM. You got $500 bucks. Then feel free to take that chance.
With this being an informational thread I put together some time ago, as a guide to jump starting, I did not intend for it to go on as far as it has. Most threads I do as guidelines, I usuallly I close them because it's nothing I'm looking to set up for debate. This thread, I just didn't close it. I am going to open it back up because it seems, many members would like to add their own experience.:cheers:
This thread has been gone over throughly. It was meant as a guideline for jumping your ski, according to BRP's recommendations.
To answer your question Greyrider, no, it does not apply to jump boxes. I don't remember what post number this is, but it's up there. If you go through this entire thread, you will see that it's already stated that the jump boxes are fine. It's also stated that the reason why you do not jump start with a running vehicle is because of the "possibility" (key word, possibility) that you might do permanent damage to your electrical system. When jumping from another vehicle that is running, there charging system is in operation. Which means, the battery is receiving 14 VDC. When you jump start from that system and your engine starts, you have 2 different type charging systems grounding to each other.
This does not mean that your MPEM or rectifier is "going" to blow, it simply means that you are taking a chance. With the price of our MPEM's in the hundreads, if not thousands of dollars, I would think it's better to take preventitve action than it is to take the chance.
As with overheating the starter, melting wires. This is true with anything that has a starter. The starter draws 90% of the batteries CCA (cold cranking amps) during initial startup. The starter is a high torque motor and has to overcome the engines compression to turn the crankshaft over. According to BRP and stated in the shop manual, you should only turn your starter over for 30 second intervals. If your troubleshooting or having a hard time starting, grab your ground wire and see how hot it is. If your battery cable wires are getting hot, shut down the engine and let the system rest.
My advice:...Never, Never, Never jump start a Rotax engine with a battery from a running engine. Did, I say Never?...Just checking. You may be lucky several times but eventually, your going to be paying for a new MPEM. You got $500 bucks. Then feel free to take that chance.
With this being an informational thread I put together some time ago, as a guide to jump starting, I did not intend for it to go on as far as it has. Most threads I do as guidelines, I usuallly I close them because it's nothing I'm looking to set up for debate. This thread, I just didn't close it. I am going to open it back up because it seems, many members would like to add their own experience.:cheers:
Last edited by a moderator:
luckysaturn13
New Member
are the fuzes in the gray box by the motor or the gray box off to the left side? I bought my ski used non running he said ran for a bit died and had to get it towed in. said he hasnt ran since.I wonder if he used a running car to jump. I didnt ask. 
Im doing the normal routine mataince,filters,plugs, fuel lines, and carb rebuild and a brand new battery then going to investigate. I hope its because of something i already listed. The battery in there was like 5 years old and wouldnt hold a charge. If it dont run right when i get it back together im going to investigate rectifier check for spark and voltage stuff. Any tips? also how do i diagnose if he jumped and fried it? Is it Just the 5 amp fuse will keep blowing ? will it still crank over and stuff just not run right?
thanks.
Im doing the normal routine mataince,filters,plugs, fuel lines, and carb rebuild and a brand new battery then going to investigate. I hope its because of something i already listed. The battery in there was like 5 years old and wouldnt hold a charge. If it dont run right when i get it back together im going to investigate rectifier check for spark and voltage stuff. Any tips? also how do i diagnose if he jumped and fried it? Is it Just the 5 amp fuse will keep blowing ? will it still crank over and stuff just not run right?thanks.
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So - trickle charge the battery only? can we do this while connected in boat?
I didn't read this before jumping my Speedster via jump start battery. I have used it about 3 times and I had a fire start in the boat... my voltage regular caught on fire while towing a skiier. Luckily - boat is ok, but is now in the shop (several hundred I'm sure... as quote to start was 380+.
voltage regular melted and all wires connected. Take this warning above seriously.
I wish I had seen it before.
I didn't read this before jumping my Speedster via jump start battery. I have used it about 3 times and I had a fire start in the boat... my voltage regular caught on fire while towing a skiier. Luckily - boat is ok, but is now in the shop (several hundred I'm sure... as quote to start was 380+.
voltage regular melted and all wires connected. Take this warning above seriously.
I wish I had seen it before.
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