Topic: Prestolyte Electronic Ignition

[DaveInTexas]

I had a question about the ignition the past owner installed on my 70 CB750.
I have searched for prestolyte and prestolite and only got one hit, no help w my question.  I searched under Electronic Ignition and there are hundreds of posts, a quick scan did not tell me:

a) anyone know anything about these such as if they are still made and general reliability?
b) do they require maintenance or periodic resetting? 
c)  I would really love some documents from the mfg, anyone know where to get a description, parts, operation and maintenance info on this? 

I opened the cover and it looks like it is encased in some type of rubbery cover, no ID numbers or anything.

THANKS, you guys are the best and I could not imagine tackling this project without all of you helping!
Dave

[oldfart]

Saw a lot of these back in the day.  Same company made ignitions for Harley later.  The only problem I recall with the Prestolites on the SOHCs was that the two triggers were not indiependently adjustable.  That means you are stuck with whatever accuracy they assembled it with, which may not have been the best.  Also worked on Gerex and Martek ignitions, and both installed and ran these, including Marteks on my own bike, two of them (the early ones overheated badly). 

[bwaller]

I installed a Prestolite ignition on my K3 in 1976, timed it, and have never had to readjust it. Absolutely no problems.

[DaveInTexas]

Here is my understanding, step in if you disagree:

It came with an air gap tool  I think this sets the distance between the pickup and the sender (if there is a sender).   This probably only needs to be set once and then checked maybe once a year - the thing is really not going to move or wear.

Second is the timing.  Probably you set the timing while running at a specific rpm using a strobe and that's it.  Check it maybe once a year too.  The advance is electronic and doesn't have any adjustment.

I'd still love to read the tech manual on it. 

[oldfart]

I installed a Prestolite ignition on my K3 in 1976, timed it, and have never had to readjust it. Absolutely no problems.

I was referring to the side to side timing.  That is, the 1/4 to the 2/3.  A lot of aftermarket ignitions had this off, even the Martek.  As I recall, of all the popular ones, only the Dyna and Gerex (probably another one there somewhere) were adjustable between 1/4 and 2/3.

[Terry in Australia]

I bought a new old stock prestolite ignition for my Suzuki GS1000 in 1999 and the seller sent me three of them, I eventually sold 2 and kept one, I installed it in my other CB750F2 and it started great, and I got half way around the block and it just died............... and never went again.

I still have it in a box somewhere, and should have the instruction sheet Dave, if you still need it? The seller ran a motorcycle shop in Chicago (?) before he moved to Oregon, he told me that the Prestolite ignitions were pretty poor quality, and he sent me three in the hope that one of them would work, ha ha! Cheers, Terry.