By steve on Unrecorded Date: Edit

OK, I have heard that some of the Cuyuna engines come equipped with CDI ignition systems. I have the guts pulled out of my 400 JLO and it occured to me that if I could convert it to a CDI type ignition and lose the ignition points, it would be a more dependable, easier starting motor. I am not afraid to get into something new.

I know that if this is a practical conversion, that someone out there has probably already done it. Let me know if you have some knowledge of this subject.

On a lesser note, are the little transistor modules like you can get to put on your signle cylinder lawnmovers adaptable for a 2 cylinder engine?

I am happy to overkill my machine to facilatate a good starting engine. Down here in Memphis, Tennnessee, people dont know what these 6 wheel machines are about.

Steve

By schunn on Unrecorded Date: Edit

Has no one looked at updating the JLO ignition? There was a fellow down south that had some experience updating point style to transistor style ignitions. Can't remember his name though. Anyone help?

Steve

By Attex Bob on Unrecorded Date: Edit

Sorry, I have no idea. I have no problems with my points in my 500..........yet.

By Argohunter (Argohunter) on Unrecorded Date: Edit

CDI boxes are fairly expensive new. Be sure it's what you really want to do.

By schunn on Unrecorded Date: Edit

I am a high tech sort of guy. I see the breaker point controlled transistor modules used on the lawn mowers with good results. Although I would really like to get rid of the points, it appears the full CDI may be more trouble than I am willing to go to, only because I don't want to have to break all new ground. I don't see any reasons why the point controlled transistor modules would not work properly. I just need to get a couple of em and install em inside the magneto flywheel.

Steve

By Argohunter (Argohunter) on Unrecorded Date: Edit

Steve, food for thought: in the mid 70's several snowmobile manufacturers changed over from breaker point to CDI ignition on their 2 stroke engines. Maybe it would be breaking new ground for you however but it's been done a long time ago by others. In fact I believe Rupp did it in about '71 or '72. CDI is so much greater in level of controlled spark, it reduced a lot of the oil fouled spark plug problems that snowmobiles had. When oil injection came along, that made a big difference too.

I recently pulled my 32 year old Kawasaki 436cc motor for a rebuild. I had thought about CDI conversion while I had it apart on the bench. After looking at the bottom end, I decided that it was took costly to rebuild and I am thinking about just going with a Suzuki Spirit CDI/oil injection of mid 70's-early 80's vintage.

I don't know what shape your motor is in, but if it is getting loose and worn, you might think about a swap. Those Spirit engines are plentiful, more reliable than many other 2 strokes and are already CDI engineered.

Good luck whatever way you go.

By schunn on Unrecorded Date: Edit

Argohunter:

I've never heard of a Suzuky spirit. I guess that must be a snow motor. Not much like that down here in Memphis.

I am very purposefully goind thru my JLO 400. After many years of unuse and misuse, I had it running, but noticed it was too low on compression. I have it in a 100 pieces on work bench now. I get a lot of fun in working with the old motors and hopefully getting something that will be strong and dependable.

I'm trying to find oversized pistons now. My pistons are stamped "64.94" I believe this is going to be close to standard bore. Not sure of that though. At any rate, I want to find new overbore pistons and then bolt it back together.

As to the ignition, If noting else comes up on this site, I will install 2 transistor modules, which will be interlocked by the breaker points. I believe they have some timing retarding effect at cranking speeds. The transistor modules do the actual voltage switching to the coils. They say that the gap and condition of the point contacts become much less critical during operation.

I believe that when Cuyuna took over JLO, they went to a CDI ignition system on thier 2 cylinder motors. The trouble I see right off is that my flywheel has 2 coil packs (2 magnets). One pack is for ignition and the other serves as the generator coil to run the battery charging circuit.

Thanks for your post. I will continue to watch for answers that other people may have south with similar problems.

Thanks

Steve

By Argohunter (Argohunter) on Unrecorded Date: Edit

Steve,
Let us know on this post how you work it out. You are right about the Spirit motor. It is a snowmobile motor. JLO and Cuyuna also are snowmobile motors up here in WI.

Good luck

By schunn on Unrecorded Date: Edit

Argohunter.

I got an idea from attexsixwheeler to mount the magnetic picups on the outside of my existing magneto flywheel and adpat to a parted out 2 cylinder CDI system. I believe he is also trying to come up with such a system.

An externally mounted sensor could be used to exite the CDI to fire at the correct crankshaft rotation. As I am unfamiliar with the CDI components commonly found on snowmobiles and skidoos, I am not sure of the exact components. In principal, if you could acquire the entire CDI system from the pickup down to the spark plug wire you would then be faced with how to attach the pick up sensors, which I believe would normally be magnetic type and then how to properly phase in the spark to the correct cylinder at the correct degree of rotation. That part could be real tricky. JLO specifies timing to occur at .xxx inchs before TDC. It is made easier as each time the piston goes to TDC it must fire. ON pointed JLOs, the number 2 piston timing for fire is fixed by the relative position of the number 2 point set on the stock ignition point plate. With CDI, I assume you would want to remove the point plate and its coils. Making the timing occur at the right instant on number two would also be a function of when it approaches TDC. The whole topic seems to suggest to me that establishing the location of the pickup sensor and timing the correct firing would be easier if the guts were all outside of the flywheel. The aluminum housing could then be used to mount the sensors and pickups for the firing.

My aatv is an old Attex. It is a rarity in this part of the world. When I pull this rascal in to the hunting woods, I want to see stares of amazement from the guys with the $6,000 4 wheelers. Part of being able to do that is having a reliable ignition system that will enable you to start on first turn of the starter motor and not require you to turn the motor over and over and hope that it will start up.

I am confident that I can update the ignition to what I am looking for. I just don't want to have to experiment with procurring systems that may or may not work on my engine. Have you priced the new cost for such a system. You could easily lay down more than $500 at the dealer.

We'll get there though.

Steve