No Start

[robin savell lloyd]

without dusthawk's feed back it is going to be inpossible for us to figure this one out. he has probroly all ready fixed it and has been out on the water the last few days enjoying himself, when he get back and sees all these post he will think to him self why wernt we doing the same thing.

 

[kustomkarl]

I agree...we ran with a tangent and got him all confused till he gave up on us... or sold it and got a Yamaha..lol
Karl

 

[robin savell lloyd]

dusthawk's ski ???

If dusthawk's seadoo looks like this one than I can see how none of what we said will help him.

 

[kayak]

If dusthawk's seadoo looks like this one than I can see how none of what we said will help him.

This seadoo belongs to a honda civic driver.

 

[robin savell lloyd]

I bet top end is scary

 

[kustomkarl]

Talk about a FART CAN...:rofl: :ack:

 

[seadoosnipe]

Mpem....

O.K...then maybe you can explain one more thing for me that will clear it all up. Why is it that the mpem is set to send two different signals to the coil at two different times. One on center (bk-rd wire) and one to send spark at 180* degrees, which would be for the other cylinder at TDC, (bk) with the 3rd wire being a ground wire.
Then the other thing I'm wondering about, is if the primary winding sets up the beginning electrical phase and the secondary winding takes that charge up to 40,000 volts, how can it deliver two sparks at the same time? That would the plug is firiing at 20,000 verses 40.
I'm a bit stumped on this one.
I have my 787 apart right now and can do this same test pretty easily. I'll do this myself and I'll either get back to you and congratulate you on bringing to my attention that for all practical purposes, should be impossible....or I'll make sure you realize that I've done this for a long time and have never in my 49 years come across this type of electrical system before in my life.
I'm still wondering why, if what your saying is true, why have does the engine need to be timed?.........
You'll hear from me again soon..........

 

[kustomkarl]

Louis, I understand what you are saying, and have looked into this also. I can't get a straight answer from anyone except from what members here have answered back on the forum. I don't claim to be a know it all, and would like to know the answer also. By common rules and the rules of physics ...it shouldn't happen this way...I just can't find proof that the standard 2 stroke engine is firing at BDC and TDC...I might take up drinking, as I haven't slept for 2 weeks over this issue...uh, well the last 2 days of dispute anyway.( it sounded good) I know if the truth is hidden somewhere you will find it. Please keep us on top of it. :cheers:

 

[seadoosnipe]

Well, here's the straight answer!

O.K. DAWG, ROBIN.........ya'll were killing me!..........this has gone on long enough. The principles in which the two of you seem to agree on, goes against everything I've ever learned in the theory of how the 2 cycle and 4 cycle engines work.
The models I've posted on line for you to look at, show an obvious spark on the upper (compbustion) stroke on the animation and no spark at all when the model is down on the exhaust/intake stroke.
Now, because I had to get to the bottom of this, I went out to my 787, where I already have the heads removed and the pistons open, which has allowed me to see TDC and BTDC and I grounded both my plugs with grounding clips.
No, hears the good part, when I roll my engine over, THERE IS SPARK ON THE TOP STROKE AND BOTTOM STROKE. BOTH PLUGS DO IGNITE AT THE SAME TIME!.....I will never mind admitting when I'm wrong and here, I'm obviously wrong.
Thanks for not letting this die you two, because I may have gone on the rest of my life believing something that wasn't true. But, it did take me to go out and perform the test myself to make sure of what you were saying. Sometime, you just got to find out for yourself.
Good job Dennis and Robin...........I say, stay on top of me. If you think I'm giving out bum dope, call me out on it.
I'm only human too and am just as foulable as the next person.
Now, get rid of that big head, we got work to do. Let's get this guys PWC fixed. Dennis, find out about the air being sucked in between the carbs and Robin, tell him to make more responses if he wants something done in this forum.
Oh, ya'll make sure you bookmark this post.........it ain't often I admit I'm wrong!................:cheers:

 

[kustomkarl]

Heading for the funny farm!

Uh Louis, I did the same test when Dennis said he did his test...It doesn't make sense to me either except the coil only has 2 wires going into it. I am baffled too...it must be a seadoo miracle!
LONG LIVE SEADOO...the god of the water craft! oops! sorry, got carried away...now about Jeffs Seadoo problem...

I hope there is room for the 2 of us on the seadoo funny farm!:rofl:

 

[Dennis]

Ignition

Does this mean my headache will go away? LOL
DAWG

 

[kustomkarl]

Dawg, I never saw more than 2 wires going to the single coil ...I think a black and a black w/ white wire if my memories is correct. I read so many manuals on this subject. I am confussed too..

 

[robin savell lloyd]

I know this is not a sedoo but I thought it was very intresting. look at page 6 i have never seen it like this in detail. hope it helps you as it did me. ps. I did not read it all but maybe one day.http://www.jetav8r.com/Vision/Ignition/cdi.pdf

 

[kustomkarl]

That's a interesting article, but a lot of the components don't apply to a seadoo.

 

[robin savell lloyd]

what I thougt was intresting was how spark and power all came to gether, again page 6. hope all will think about it and not just blow it off as not important.

 

[kustomkarl]

It is a nice find about the system and how it works...

 

[seadoosnipe]

Great link!....

Robin, that was a great link. Although it does explain the basics of the beginnings of the spark plug and ignition system, I'd think a lot of that material is out of date. I did see that the manual was scanned into PDF format in 2005 and toward the end of the book, the patents go back to 1916. I read several pages of this book because it brought back memories of my street rod days. My first high performace engine builds were the 287, 327, 350 and 400 small block chevy motors. And all that I read in that book, reminded me of the carbon points ignition. I did have one distributer that ran on the double points ignition. Man, were they a royal pain in the butt. You were constantly taking emory clotch to them to clean off deposits. I used the Mallory ignition system.
In todays real world, you can't work on any of this. It's designed to last the life time of the car or if it doesn't, you just throw it aways and buy new. Like spark plugs, we used to have to replace them every few thousand miles because a carbeurated engine doesn't burn cleanly, causing deposits and fouling plugs. When they came along with the fuel injection systems, that changed everything. Now, you can use plugs for up to 75,000 miles.
My initial disbelief of that 2 sparks during the cycle went against everything I had learned about the 2 and 4 cycle engines. Advancing my timing or to retard my timing (changing the time the plug fires in relation to the pistons postion) was something we all did come time to race. You could actually had a coule extra horsepower by doing this. But you could also bend your push rods.
My thoughts also behind the obvious (wasted spark) second spark was in part because, the amount of voltage it takes to make a spark plug work is anywhere between 20 and 50 K volts. Depending what application it runs. And to think that the Sea-Doo ignition was capable of making that kind of voltage that fast, was unbelievable. But it does. And for what I see is the only reason, to cut down the complexity of the electrical system.
Sorry for the long post, but I did book mark that link you sent. I plan to do some more reading in it, for nothing else, to bring back old memories and maybe refresh my brain on some of that info that has fallen out that hole in the back. You know, the plug does fall out from time to time....
Great post Robin

 

[kustomkarl]

Louis, your giving away your age again...now we know your older than dirt!
Karl

 

[robin savell lloyd]

Well, I was wrong. I thought fuel was getting to the combustion chamber but apparently it isn't. I did like the manual said and sprayed WD-40 through the flame arrestor while cranking but it still didn't start. I then pulled the plugs and they were dry as a bone.

I wonder why it would not start with wd40 do you think you had a weak spark? :hat: