Arlie Endsley Wrote:
> Todd Keingeshaft did the yt60 head work by its
> self? also what about the yt60 CDI or would the
> jog CDI work better? I have heard of a few Towny
> guys using the yt60 CDI to help with a kit.
The YT60 head helped, but to keep the temps down I still had to run the jetting pretty rich, AND use a "thick" head gasket with it to lower the compression some. I never soft-seized with the YT60 head, but by then I also had a head temp gauge, so I could keep an eye on the temps and avoid soft-seizing. Once I added the Jog CDI, though, my overheating problems were gone!
There is NO difference between the QT50 CDI, The Towny CDI, and the YT60 CDI. I have had all of them apart, and drew schematics for each of them, and the circuits are identical, despite the different part numbers. I posted about this a long time ago, but the last time I looked up the post for someone, a majority of my post was deleted for some reason.
The CDI I am using now is one of these:
If I remember correctly, that CDI retards the ignition about 6 degrees above 7000 RPM. That alone does wonders for keeping the engine temps down!
I bought one of those "blue aluminum" CDIs last year sometime, took it apart to draw a schematic of it, then never did anything else with it. One of these days I'll get around to trying it out, but from what I remember, the circuit wasn't anything special...
Keep the advice about air leaks and stuff that others have posted in mind while you troubleshoot this though. I posted my experiences because my engine was airtight, my jetting was spot-on, and yet I still soft-seized. Once you are sure that your engine has none of the issues that others have posted, you should then look into what I have mentioned...