Big Pin vs Small Pin Electrics/Ignition

Location
PA
Swapping a small pin engine hull with a later big pin motor. Can a small pin Ebox and stator be swapped onto a big pin motor? Pros? Cons?
 
Location
dfw
I know the 3729 cdi is junk because it has no high rpm retard and no rev limiter that I could find. These are found on 1992 750sx. The better small pin cdi is marked 3733, 3734, 3735 and the 1995-2003 big pin was 3738. The 3738 has a retard curve and an 8000 rpm limit. I have not tested the other small pin CDIs but plan to soon.
 
Location
PA
I know the 3729 cdi is junk because it has no high rpm retard and no rev limiter that I could find. These are found on 1992 750sx. The better small pin cdi is marked 3733, 3734, 3735 and the 1995-2003 big pin was 3738. The 3738 has a retard curve and an 8000 rpm limit. I have not tested the other small pin CDIs but plan to soon.
Thank you Kevbo that was exactly what I was looking for!

I never know what Ignitions I can swap out without an issue. I figure differences with the same motor wouldn't matter too much but I wasn't sure big pin to small pin if that advance curve was required with the port timing differences.

What is the rpm limit on the early 33, 34, and 35's?

I have a $1600 92 750 SX that is my loaner ski. Had a spotless original motor in it that I put a lower cc stock kawi casting head on and a timing advance plate. The little ski ripped, but after some extended WOT hard riding I burned a hole in a piston ha ha! Not sure if it was all due to the advance or maybe the old crank seals were leaking??? Some swear the advance plate is fine, others swear they are a problem on pump gas.

I rebuilt a big pin out of fresh spare parts so it was easy to just swap whole motors out and I'll rebuild the small pin when I get around to it. I just didn't know if the same older small pin ignition would be fine. NewMiller milled the head and lightened the flywheel, other than that it's stock big pin I was planning on bolting the single carb back up to.

I also have a MSD igniter but not sure if that too would be too much advance?
 

Scorn800

Ride for life
Location
North NJ
Do not use the MSD enhancer and the advance plate together, it will be too much timing advance
You burnted a hole in the piston from too much load on the motor- either by too high of compression, too much timing or too steep a pitch prop or all of it together.
 
Location
dfw
I dont know the specs on later small pin boxes, yet. I have several boxes to test. I am currently assembling a 1994 750sx. I'll mark the flywheel, get my timing light and tach and test them all soon. I do know the 1992 cdi has no high rpm retard so stock starts at 16 degrees + your 6 degree plate. This can be a little much for safe full throttle runs, depending on fuel and compression. Yamaha CDIs were very consistent over the years but Kawasakis need to be checked since some combinations can be dangerous. Keep in mind most aftermarket flywheels also advance timing.
 
Location
PA
Thanks for the info! Yeah, seems I hit the wrong combo, higher compression, no retard igniter, and the advance plate. No biggie, was an old spare ski. Ran several years like a champ. was perfect for a novice but once I started to push it, it didn't last long.

Anyone have a -3738 igniter for sale?
 
A02t will work with both yamaha 760 and kawi 750/800 stock electronics. To run in the kawi you will need to set the static angle up at 47 degrees instead of 56 degrees for the yamaha. You can download the program on zeel website and buy the USB program cable and set it up for any engine combo.
 
I don't have any A02T Zeeltronic units but I have a couple of "Kawasaki" version -02T and they just came with a pigtail, and the static angle and other settings were not set up for Kawasaki. Was no problem to wire them up and program them but they weren't plug and play as some people would want. I'm not sure if that is still the case
I used a a02t in the kawi no problem just cut the Yamaha connector off and run bullet connectors like oem. That's what I did. Actually set my Yamaha up with bullets as well so I can swap cdis between both setups and program as needed
 
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