Hi All
I just stumbled on this site while looking for an alternative ignition for the Rotax / Bombardier in an old jetski.
It’s a 2 stroke twin about 580cc. Ski has 12v system. Current CDI and coils are broken and replacements rare and expensive.
A quick search of this site found nothing on 2 strokes. Any advice welcome. Please try and sell me one. Im sure it will be a rewarding project.
Use on a 2-stroke?
Moderators: JeffC, rdoherty, stieg, brentp
Hello,
I do not recall an existing application using Ford EDIS and a 2 cycle engine, and a brief bit of research on the 'net yielded no information.
However, The Ford EDIS is a wasted spark system, meaning it fires on the compression stroke as well as the exhaust stroke. Since a 2 cycle engine sparks on every stroke, it seems like it could work.
Start with an EDIS-4 configuration, and use one channel to fire into a single coil. The other channel on the EDIS module would not be used.
A single coil could consist of a pencil "coil on plug" coil pack, found on more modern vehicles (circa 2000-2002). Ensure it's a 2 terminal coil pack *without* the built-in drivers.
Here's the bit of good news: since the Ford EDIS module runs by itself in "limp home", with timing fixed to 10 degrees BTDC, you can pick up the ignition parts cheaply and conduct some testing, before investing in the full system.
See the installation guide here http://www.autosportlabs.net/MJLJ_V4_ve ... tion_guide for additional details. If you do make progress, please let us know!
Regards,
I do not recall an existing application using Ford EDIS and a 2 cycle engine, and a brief bit of research on the 'net yielded no information.
However, The Ford EDIS is a wasted spark system, meaning it fires on the compression stroke as well as the exhaust stroke. Since a 2 cycle engine sparks on every stroke, it seems like it could work.
Start with an EDIS-4 configuration, and use one channel to fire into a single coil. The other channel on the EDIS module would not be used.
A single coil could consist of a pencil "coil on plug" coil pack, found on more modern vehicles (circa 2000-2002). Ensure it's a 2 terminal coil pack *without* the built-in drivers.
Here's the bit of good news: since the Ford EDIS module runs by itself in "limp home", with timing fixed to 10 degrees BTDC, you can pick up the ignition parts cheaply and conduct some testing, before investing in the full system.
See the installation guide here http://www.autosportlabs.net/MJLJ_V4_ve ... tion_guide for additional details. If you do make progress, please let us know!
Regards,
Thanks for that Brent.
You wouldn’t believe the flack I’m getting from a US jetski forum even suggesting an alternative ignition system. An original used replacement is about $200 in US and since Im in UK would probably be much more, but thats not the whole point.
The Plug on Coil systems (from ebay) look a bit long and may suffer from the pounding a jetski gets unless anyone knows of a short/light setup. Perhaps better to bolt down the ford coil packs and use conventional leads.
Is that list of compatible EDIS-4 complete? The last Ford listed is 1993 in UK and my local large salvage has none. What about newer ones? Did they change the system?
The trigger wheel may have to be a one off. Do you know of a minimum size that would still work? Better I think to get it inside the Mag end enclosure than exposed to an oil and seawater soup in the bilge. Is the higher rpm likely to be an issue for the sensor to separate the pulses? I would need a rev limiter otherwise it would scream when sucking air.
I know it will be risky as any mistiming would quickly result in an expensive rebuild but I am keen to give it a go.
Cheers Vince
You wouldn’t believe the flack I’m getting from a US jetski forum even suggesting an alternative ignition system. An original used replacement is about $200 in US and since Im in UK would probably be much more, but thats not the whole point.
The Plug on Coil systems (from ebay) look a bit long and may suffer from the pounding a jetski gets unless anyone knows of a short/light setup. Perhaps better to bolt down the ford coil packs and use conventional leads.
Is that list of compatible EDIS-4 complete? The last Ford listed is 1993 in UK and my local large salvage has none. What about newer ones? Did they change the system?
The trigger wheel may have to be a one off. Do you know of a minimum size that would still work? Better I think to get it inside the Mag end enclosure than exposed to an oil and seawater soup in the bilge. Is the higher rpm likely to be an issue for the sensor to separate the pulses? I would need a rev limiter otherwise it would scream when sucking air.
I know it will be risky as any mistiming would quickly result in an expensive rebuild but I am keen to give it a go.
Cheers Vince
You may want to look for a "plug-near coil" coil-pack, which has a short pigtail HV lead, or possibly find a coil-on-plug module that is shorter; or even perform a bit of 'modification' on a unit which may be close to fitting.
If the donor vehicle list we have in the installation guide isn't complete we would like to know so we can make the appropriate updates. EDIS-4 modules should be reasonably common in the UK- they appear in many 93-99 Ford vehicles.
The trigger wheel and sensor combination may take many forms- large or small, typically using the Ford VR sensor. The Zetec motors have the trigger wheel pattern machined into the flywheel, where the Ford Escorts have a standard crank pulley mounted trigger wheel.
On custom installations some have used very small trigger wheels with a sensor from an RX7; a recent success: http://www.autosportlabs.org/viewtopic.php?t=2026
In any case, when deviating from the 'standard recipe' (such as using a recycled Ford trigger wheel or similar) one must ensure the design generates a strong, clean signal, as the EDIS module needs this to maintain crank synchronization.
If the donor vehicle list we have in the installation guide isn't complete we would like to know so we can make the appropriate updates. EDIS-4 modules should be reasonably common in the UK- they appear in many 93-99 Ford vehicles.
The trigger wheel and sensor combination may take many forms- large or small, typically using the Ford VR sensor. The Zetec motors have the trigger wheel pattern machined into the flywheel, where the Ford Escorts have a standard crank pulley mounted trigger wheel.
On custom installations some have used very small trigger wheels with a sensor from an RX7; a recent success: http://www.autosportlabs.org/viewtopic.php?t=2026
In any case, when deviating from the 'standard recipe' (such as using a recycled Ford trigger wheel or similar) one must ensure the design generates a strong, clean signal, as the EDIS module needs this to maintain crank synchronization.
Thank Rich, I see the whole EDIS system, less trigger wheel are available for about j40 and trigger wheels about j14 but think I shall make my own.
Brent
The good news is that there is loads of room inside the waterproof Mag end for a full size wheel. There are also unused tapped holes perfect for sensor mounting.
Question on soft rev limiting.
I see the soft limit when enabled fires at TDC. Im not sure if this will limit an unloaded 2 stroke. The EDIS units will accept a SAW to drive it to 10 ATDC (I think). Can I MAP a 10 ATDC at a set RPM to act as a limit if 0 BTDC doesn’t limit it (just trying to avoid an external limiter).
Am I right in assuming that firing later than the ‘normal’ point will never damage an engine?
Brent
The good news is that there is loads of room inside the waterproof Mag end for a full size wheel. There are also unused tapped holes perfect for sensor mounting.
Question on soft rev limiting.
I see the soft limit when enabled fires at TDC. Im not sure if this will limit an unloaded 2 stroke. The EDIS units will accept a SAW to drive it to 10 ATDC (I think). Can I MAP a 10 ATDC at a set RPM to act as a limit if 0 BTDC doesn’t limit it (just trying to avoid an external limiter).
Am I right in assuming that firing later than the ‘normal’ point will never damage an engine?
It would require a firmware change to do 10 ATDC upon soft-rev limit, as the system is not aware of negative advance values. The external limiter is extremely effective, however, and can be cleanly installed in the same enclosure as the unit.
I cannot see how 10 degrees ATDC would damage the engine. Might get some good flames though- perhaps that might damage the cowling?
I cannot see how 10 degrees ATDC would damage the engine. Might get some good flames though- perhaps that might damage the cowling?
Wow quick response, thanks.
Don’t think I would have a rocket with very retarded spark as water is injected just after exhaust manifold (to help the tuned pipe it says?). The exhaust has a long journey through a water box thing before seeing daylight.
Hope you will consider allowing –ve values in advance and MSD in future software. Bit cheeky of me asking as I haven’t got one yet.
Slightly off thread.
A few years ago I had a single seat aircraft powered by 1900cc VW. For safety it had 2 mags driven by single chain! and 2 plugs per cylinder. It was an absolute pig to start as had to hand swing prop and fixed advance. This system would be great to replace one of the independent ignitions but I expect legal alarm bells would ring. It was on a ‘permit’ so some home brewed solutions were allowed.
Cheers
Vince
Don’t think I would have a rocket with very retarded spark as water is injected just after exhaust manifold (to help the tuned pipe it says?). The exhaust has a long journey through a water box thing before seeing daylight.
Hope you will consider allowing –ve values in advance and MSD in future software. Bit cheeky of me asking as I haven’t got one yet.
Slightly off thread.
A few years ago I had a single seat aircraft powered by 1900cc VW. For safety it had 2 mags driven by single chain! and 2 plugs per cylinder. It was an absolute pig to start as had to hand swing prop and fixed advance. This system would be great to replace one of the independent ignitions but I expect legal alarm bells would ring. It was on a ‘permit’ so some home brewed solutions were allowed.
Cheers
Vince
All the ford EDIS bits arrived this morning so I am trying to figure out how to hold the sensor and what size trigger wheel to order. It has just occurred to me that I will be bolting the trigger wheel to the flywheel which on a 2 stroke contains very powerful magnets.
Brent or anyone. Is there likely to be a problem with the magnets swamping the trigger pulses?
Also I see there are some helpful links here for building an advance map for 4 strokes. Any help or links for 2 stroke stuff would be appreciated as I can find very little. It seems almost none use any sort of load sensing MAP/TPS.
Cheers
Vince
Brent or anyone. Is there likely to be a problem with the magnets swamping the trigger pulses?
Also I see there are some helpful links here for building an advance map for 4 strokes. Any help or links for 2 stroke stuff would be appreciated as I can find very little. It seems almost none use any sort of load sensing MAP/TPS.
Cheers
Vince
Hi again Brent.
In your first reply you suggest using one coil channel to fire both plugs. As I need a spark every 180deg I think I will need both channels, using one output from each coil. Is that right?
If so that leads me to another question. If one half of a coil is not being used, is it ok to leave the socket blanked off? Should I ‘T’ both outputs into a single HT lead or would that kill the spark?
Just out of curiosity what voltage is present on the coil output channel, I assume it simply grounds the 12v supply?
I was concerned about the flywheel magnets in my last post but remarkably there seem to me no sign of magnetism on the opposite (outside) of the flywheel, but we shall see.
Cheers
Vince.
In your first reply you suggest using one coil channel to fire both plugs. As I need a spark every 180deg I think I will need both channels, using one output from each coil. Is that right?
If so that leads me to another question. If one half of a coil is not being used, is it ok to leave the socket blanked off? Should I ‘T’ both outputs into a single HT lead or would that kill the spark?
Just out of curiosity what voltage is present on the coil output channel, I assume it simply grounds the 12v supply?
I was concerned about the flywheel magnets in my last post but remarkably there seem to me no sign of magnetism on the opposite (outside) of the flywheel, but we shall see.
Cheers
Vince.
Today I had the Rotax engine running for the first time on a stand with the standard EDIS4 set up. 4.5in trigger wheel and VR from triggerwheels. The sensor has gone in unbelievably neatly as if done by the manufacturer. So far I have no MJL fitted so firing at 10BTDC.
All seems OK at idle but it is going to be tricky setting it up as 101 other things have also been done to the engine & carbs and it seems I will pioneering the ignition map on this engine (or indeed any 2 stroke).
I am getting a blurry strobe picture. Not sure if it’s the cheap in-line light or a genuine unsteady spark. I seem to remember reading about this on this site but cant find it again.
The usual set up is for this engine to fire at 21BTDC at 6000 rpm. Can anyone suggest a good starting place for idle timing. Hope to get some pics of soon of this setup.
Cheers
Vince
All seems OK at idle but it is going to be tricky setting it up as 101 other things have also been done to the engine & carbs and it seems I will pioneering the ignition map on this engine (or indeed any 2 stroke).
I am getting a blurry strobe picture. Not sure if it’s the cheap in-line light or a genuine unsteady spark. I seem to remember reading about this on this site but cant find it again.
The usual set up is for this engine to fire at 21BTDC at 6000 rpm. Can anyone suggest a good starting place for idle timing. Hope to get some pics of soon of this setup.
Cheers
Vince