Peter, I bet you are correct. I was struggling with it after I put it on line, and wondering about a power loss with the HSR at only some 8 degrees advance at 8000 RPM, per the comparison graph in the above post. EDIT: THAT GRAPH WAS INCORRECT AND I DELETED IT. I made the assumption that each verti...

Both the standard Invader and the 4/6 came with 36mm Mikuni Power Jets. What did Liquifires come with?

The 4/6 had more ports in the cylinders, dual plug heads, twin pipes (along with a bigger radiator and a few other trim things). It is my understanding that the ignition system wasn't as good as the standard Invader. I heard that the system was closer to the old technology used on the dual plug Arct...

My Invader doesn't have dual sparkplug heads. That was only on the 80' 4/6 Invader LTD. And it used a different ignition than the standard Invader.

Thanks for the info. Now I know what I am looking for.

That would be great if you could post that. Thank you. I have been assuming that the 80-81 Liquifire ignition was the same as the Invaders, but I don't think my Invader has a rev limiter. Are they the same? Could someone post a picture of the 82-84 ignition/engine? I am heading to the local snowmobi...

Ok, I have a couple more questions. I read that the Liquifire has a rev limiter? Is this built in to the cdi? Seperate unit?

Why do they call it HSRI High Speed Retard Ignition? Shouldn't the ignition advance at higher RPM?

I heard that Deere made the flywheel heavier to compensate for the lighter (than an Invader) clutch. Is this true? If so, did Deere lighten the flywheel when they switched to the TR-800?

Is there an easy way to tell the difference between the 80-81 and 82-84's by looking at the outside? Different decals?

The engine came with a seperate coil and cdi. But I am in the process of building the engine right now, and the only electrical piece installed is the stator. I don't even have the flywheel on yet so it would be easy to change it. If I wanted to change it what parts would I need? Stator? CDI/coil? I...

I have a nice set of 4/6 dual plug heads, but I opted to use single plug Invader heads that have been shaved.

I am building a modded Invader motor and was wondering if there would be any gains to be had by running the updated JD ignition?

Does the 82-84 Liquifire make more HP than the 80-81? Would there be any benefit in running the 82-84 CDI over the 80-81?

I guess I will run my NOS pistons/rings. If I burn it down, I will deal with it then...

I am building a modified 440 Invader engine. I am trying to determine what would be the best choice for pistons. I have ported NOS cylinders, milled heads (both done to Aaen spec), and Aaen pipes. I am building the motor from the ground up, and I am wondering what is the best piston choice. It seems...

The ones on ebay have the tabs on them. I think they will fit... I am going to buy one. Thanks for the help. I will report back if they fit or not.