I Got It ! - I Get By With a Little Help From My Friends

Finally... I know what was causing my woes (besides dain bramage). How long have I been working on this rough engine problem? Two months? Three months? Four?

The problem was finally traced to vibration of the bracket that holds the pickup sensors.

Now, how did I come to that conclusion?

Several of my advisers suggested getting my hands on an oscilloscope (see the previous post). After I sent out the results of that test, two experts said that my problem was the variation in amplitude in the signal - not a phase shift, and was most likely caused by vibration.


I got hold of Don Bartlett (who doesn't like me very much) and he welded a couple of gussets onto the new bracket made by Phil Lankford and Jeff Doddridge, in California.


When I first fired it up, I could tell that things were better, but still not 100%. It ran well on the mag, but not on the electronic ignition, but the fuel injection seemed fine. Fortunately, I had experience with this and figured it was just dirty spark plugs.

I let the thing cool off for an hour, pulled and cleaned the automotive plugs, then stuck them back in.

When I fired it up it ran just great! Wow!!! Did I say great? I really meant fantastic! I brought it up all the way to 2,370 RPM, which I hadn't seen in a long, long time! There was still a slight roughness when running on the electronic ignition, but nothing like before. I think I need some bracing of the sensor bracket, but at least I know what to do!

I want to thank all you guys who were helping me on this frustrating, teeth gnashing, hair pulling episode. I'm going to take a couple of days off for a Hoskins family reunion, but I'll be back at it on Tuesday.

Thanks again, all!