Fred Head Questions

[YetiWoodz]

Alright, its .8mm all the way to the edge!! I tried gum again, but its just too sticky and weak, I even tried putting in the fridge to cool it, but it still got everywhere. So I used kneaded eraser. It feels similar to gum, but its not as sticky and it holds together well. I put 4mm wide of that and about 1mm thick. I did 2 or 3 revolutions of the piston. The kneaded eraser worked very well.

 

[Member 30571]

Cool, Now put it all together and go riding..

 

[YetiWoodz]

There is a big misconception about these heads,many call them high compression witch actually they are NOT in Yeti's case because he got a 5.5cc chamber yes it is but most are 7-8cc and stock is 6cc so the gain is better chamber shape/design and WAY better cooling witch allows a better performance tune to be safely used but there really isn't any bolt on gains to be had from them performance wise.

In the future if I wanted to put a proper expansion chamber on, will it work good with my 5.5cc chamber, or will that cause too much compression or way less longevity than if it was just the expansion chamber and no high comp head?

 

[HumanPerson]

Good job Yetibug!

 

[YetiWoodz]

Good job Yetibug!

Thanks! You guys were super helpful. And man, I love that torque wrench. It pops off when it reaches the torque level I set, so I don't have to judge it myself when its torqued enough. I'm excited to get this bike running, its been at least a month since I last rode it.

 

[Street Ryderz]

In the future if I wanted to put a proper expansion chamber on, will it work good with my 5.5cc chamber, or will that cause too much compression or way less longevity than if it was just the expansion chamber and no high comp head?

You've only bumped the compression a little bit to maybe around 8:1 from the 6:1 stock crap and 8:1 for a 2t is bang on for pump gas at 87-91 though imo 87 works best at that ratio.8:1 is not considered as high comp by any means,it's great for a 2t and will work well with a good pipe.Your going to see a big difference in how this engine acts compared to stock,enjoy man you've earned it!

 

[YetiWoodz]

Still putting my bike together, almost done. My bike ran best before with a #63 jet. I'm gonna change the gas/oil ratio from 100:1 to 40:1. So since I have new piston rings and cylinder, I gotta break it in. Should I jet up or is that change in gas/oil ratio all I need?

 

[Street Ryderz]

Still putting my bike together, almost done. My bike ran best before with a #63 jet. I'm gonna change the gas/oil ratio from 100:1 to 40:1. So since I have new piston rings and cylinder, I gotta break it in. Should I jet up or is that change in gas/oil ratio all I need?

You may want to jet up a couple or few to be safe it's going to flow differently.

 

[YetiWoodz]

I got it all together. I went and checked that everything is tight. After several tries, I still got no spark, but everything else sounds and feels good. I have new spark plugs and gapped, made sure the boot is all the way on, the cylinder head is tight. I didn't touch any of the electrical stuff since I last got my bike running. What should I check next?

 

[Member 30571]

Disconnect the kill button then try it. I had mine short out I unhooked it and it started right up.