Rupp nitro 2 spark on one plug

[74ruppnitro2]

Hi, I was looking for some help on coming up with the problem with my rupp nitro 2 340. The engine is a kohler k340-2as. It has spark only on one side. I Have checked the coils and the plugs and that doesn't seem like the problem. The next think I looked into was the cdi box/ electromag. The two wires that come out of th back of it goes to both coils. One wire I tried hooking to both coils at different times and had spark on both the other wire I can't get anything off of it. So I'm not sure if the cdi box is bad of if there is something else I should be looking for. Thanks
Joe

[Johnny Speed]

The Kohler cdi fires each cylinder independently and the red and white wires to the coils have to be oriented correctly, likely your cdi box is bad, easy to swap in a good one to test

[74ruppnitro2]

Thanks for the help. I am not 100% where I can find a cdi box. I bought one off of eBay before and it had different hook ups and wasn't not sure how to wire it up so they told me to send it back. Does anyone know where I can find one?

[mrrupp1]

There are two CDI boxes Rupp used on there Kohler motor sleds. The Nitro II most all used the A box which had the connector's molded to the box. The B box were used on the later Nitro 75 fan and I think all the 75 Free Airs. The B box the connectors are not molded into the box. They are on a pig tail that come out of the box. There is a guy that builds new CDI boxes. The web site is www.cdibox.com. They are way better then the old ones.

[kerry]

I dont want to confuse this conversation BUT one of my motors I had for mine was a kohler 440 2as which was not from a rupp (the fan shroud tag just had Kohler not RUPP on it) and the trigger coil wires were different from the rupp wire layout to the cdi box.I used the prestolite A and B diagram that cdibox.com has on their website to figure out which wire was to go to where.It has been a couple yrs since so not really sure which but it is there.
Kerry

[daren007]

All parts are interchange, boxes, Stators and Triggers. You can mix and match any combination. You will have to come up with the wiring plugs to adapt the molded box to the conventional harness. By using a VOM and working through it. It can be done. I have wiring diagrams somewhere for this. If you go to cdibox.com / Fireplug you can find help with this process.

Daren

[rupp838485]

Have you unplugged the key and kill switch and tried it?

[74ruppnitro2]

I have tried unplugging the kill switch and key and nothing changed. I just ordered a cdi box from cdibox.com. I am getting the additional wiring plugs to adapt the molded box also. I was trying to find a diagram for the engine to wire it up correctly. Not sure what wires come out of the engine do what. I got a diagram with the new cdi box that is a little confusing because I'm not sure what the wires coming out of the engine go to. Has anyone converted one over before and have a diagram that would be easy to understand ? Thanks for your time.

[kerry]

I'll take a pic of mine for you but its been a while since I traced which wire was what.I have the cdi from Scott as well on mine.
Kerry

[kerry]

Found my original posting on some of what I went through.maybe it will help.

www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwjJpZGtgqLRAhVE7IMKHeDOAvMQFggrMAI&url=http%3A%2F%2Fxenoahsark.proboards.com%2Fthread%2F8125%2Fproblem-running-340-2as&usg=AFQjCNHrktRKouKCrqU_Ko_Kvoce26cdpw

Kerry

[kerry]

Here's a pic.

[kerry]

well that didnt work

[kerry]

have another pic i will put up tomorrow.Photobucket is real slow for some reason.
Kerry

[74ruppnitro2]

Thanks Kerry. I'm just waiting for the other end of the plug to come in the mail.

[bobsapp]

Check for pinched wires, between fan housing and engine case. Back in 74, Kohler said when changing a stator. The stator and trigger assembly must be a matched set. Good Luck!

[daren007]

I have mixed and matched the Stators, Triggers and CDI"S for years with success. Scott (fireplug) says it can be done also.

This helps open options. Daren

[rupp838485]

3- wires on A - style Trigger ( Black- PTO ) (Red-MAG ) (White-GRN) you can put wire spades on these and use a B style CDI
3- wires on B - style Trigger ( Red - PTO ) (White-MAG ) ( Green-GRN)
The wires for the stator are Blue, Yellow and 2 Green 1 power 1 ground
Coil wires from Presto CDI (White) and (Red)
Coil Wires from Hewtech CDI (Black) and (Red)
I have switched all of our Rupp's over to B- Style CDIs both Prestos and Hewtech.
All our CDIs are not mounted on the motor they are on the tunnel to get away from heat and vibration.

[rupp838485]

I do not use the Rupp power board we use a terminal block.

[kerry]

3- wires on A - style Trigger ( Black- PTO ) (Red-MAG ) (White-GRN) you can put wire spades on these and use a B style CDI
3- wires on B - style Trigger ( Red - PTO ) (White-MAG ) ( Green-GRN)
The wires for the stator are Blue, Yellow and 2 Green 1 power 1 ground
Coil wires from Presto CDI (White) and (Red)
Coil Wires from Hewtech CDI (Black) and (Red)
I have switched all of our Rupp's over to B- Style CDIs both Prestos and Hewtech.
All our CDIs are not mounted on the motor they are on the tunnel to get away from heat and vibration. [/quote]

Yes thanks for the memory jog !! That is exactly what I went through.My only actual original B style trigger wires were damaged inside the housing like something had let go in there.The only other ones I had were the A style color wise and it took a little figuring to get them hooked up to the hewtech cdi and wiring.Scott's site does show all the differences between the two.It just becomes substituting A colors for B colors in the right order from the trigger.

Kerry

[kerry]

tried a couple times to post another pic of wires but photobucket is giving me a hard time.
Kerry