1978 spit fire

big danno 1970 · Post by **big danno 1970** » Fri Sep 14, 2007 9:55 am

Hi everybody, I have just picked up 2 jd sleds one is a 78 sptfire and the other is a 79 trailfire.
The spitfire has weak spark and wont fire so I was wondering if I could switch the cdi system over to an arctic cat system, seems like it should work as the sleds are of the same cc,s (3000 jag) and the pulser coil fits on the kohler mag plate,my only concern would be timing as I dont know if its done by the cdi box or if done by the flywheel/mag plate or both.
Are these motors hard to get pistons for if the need should ever arise?
By the way I would be using the whole system from the cat.
Thank you in advance

cyclone crazy · Post by **cyclone crazy** » Fri Sep 14, 2007 7:09 pm

Pistons are still available.

From what your describing- weak spark. I think your jumping the gun on replacing your CDI. I would suspect other problems are more likely or should be ruled out first. Let us know what you've already tried and maybe we could give you some suggestions to try. Using a CDI from a Kaw powered Cat on a Kohler sounds like alot of headaches to me.

JDFanPa · Post by **JDFanPa** » Fri Sep 14, 2007 9:41 pm

I dont think you can run the whole system but there is a good chance you can plug the car cdi box in and see if it gives you spark Im pretty sure the plugs are the same. But if you have weak spark you prob have a bad ground or connection in the plug caps and not a failed part.

chains1017 · Post by **chains1017** » Fri Sep 14, 2007 10:33 pm

I have crossed the boxes from deere to cat before? I found on most of the spitfires I had problems with that the sled would run and idle all day, but would pull no Rpms. 3 sleds total, arrrgggghhhhhh! If you reversed the plug wires it would run the exact same. I would do a visual comparison, as if it works, its a heck of a lot easier to find cat parts. We crossed a 79 spitfire to a 77? cat eltigre 6000 FA. I do agree though that It would be more likely another issue as it has spark and I dont think Ive personally seen a weak box just a dead one or a equalized box, what we call it(lol) I completely rebuilt a 79 spitfire trying to figure out I had one of these bastard boxes, but I can say it ran fantastic after 300.00 and alot of cussing. I think by looking at my book it was a 3002-117, but im not sure any more. I have a bunch of nippendenso coils around if you need one, I would need a number to cross it though as Im not sure which coil it was. I parted a 79 2 years ago, and dont think that coil ever sold. Well any way I just had to put my word in, I hope it helps. I cant say it makes sense, but I usually dont, LOL see ya all Doug

big danno 1970 · Post by **big danno 1970** » Sat Sep 15, 2007 4:58 pm

Thanks guys for responding so quickly!While I was waiting for your help I thought I would give it a try(changing the whole system)and I found that the pulser coil was not grounded very well so I cleaned it up and got nice bright blue spark and she fired right up,so I thought what the heck and switched it over to the cat ignition system and low and behold it fired right up and seem to run the same as the original system did.
I did alot of extra work to find this out but I had to know then I switchted it back to original again just to be on the safe side.
Thanks again guys and I hope we have lots of snow this year so we can enjoy this wonderful sport

Danzig · Post by **Danzig** » Sat Sep 15, 2007 5:03 pm

It was luck.....

How sweet it is..

JDFanPa · Post by **JDFanPa** » Sat Sep 15, 2007 7:45 pm

Thats cool maybe give us some exact info on what year model etc cat motor this stuff came from just so we can make a mental note that these parts will interchange.

Deleted User · Post by **Deleted User** » Sun Sep 16, 2007 10:04 am

The cat donor sled was a 1978 Jag 3000 340cc free air the only small mod was to elongate one of the small holes in the pulser coil which was done with a chain saw file.As for the timing I dont know for sure as I never put a light on it to be sure.
Good luck if you need to do this swap and have fun.

Spitfire79 · Post by **Spitfire79** » Mon Sep 17, 2007 1:13 pm

This is good to know.
I've got a 79 with a Kohler that is giving me grief. I have no spark and am trying to figure it out. I believe its the cdi. Can't find one. Can you give all the details of the conversion? Cat parts are a lot easier to find

Jeff

big danno 1970 · Post by **big danno 1970** » Wed Sep 19, 2007 9:54 am

Spitfire79 it is basically a bolt on process if you look at the pulser coil mounting holes and the stator plate you will see the difference in the hole spacing not a big deal but just enough to matter just get out your chain saw file and elongate the hole,holes a little to make it fit set the stator plate back in its original position and it should give you spark and hopefully run for you
I would check the timing just to be on the safe side and as far as the rest of the wires go you must figure that out on your own becaue I never got that far as it was just an experiment for me.
Good luck and keep us posted.