Zeda 85 porting suggestions

[sherron82]

That’s what I want to know lol

I'm about to get the ms380 2 ring piston myself

 

[ImpulseRocket]

The Avenger/Zeda 85/Insert other name here are all based on a... in my opinion at least, botched adaptation of a saw design. The pin location in the center of the intake port would be ok IF, like the engine it was borrowed from, the ring never went below the roof of the intake port.

That's a fatal flaw.

A different piston or a relocation of the piston pin is the only way to get around that flaw. The former is going to require some R&D. The Latter would require a bit of skill and the right size drill bit and ring pin - then hoping you do it correctly so the pin doesn't fall out.

 

[sherron82]

Where did you get it? Cost? How much work is required to get it to work?

Go max.com and it just bolts right up to the cylinder. Look on gomax.com and search for avenger 85 head.

 

[sherron82]

Go max.com and it just bolts right up to the cylinder. Look on gomax.com and search for avenger 85 head.

80 bucks

 

[sherron82]

80 bucks

 

[Gordy]

Where would you get a dome piston?

The CDH110 piston might work. @Mike Cyanide was working on using one I think

 

[Mike Cyanide]

The CDH110 piston might work. @Mike Cyanide was working on using one I think

This is correct how ever port timings may vary and viability is contingent on your skill level and tool availability(not guaranteed a bolt on solution). However mine appears to be pretty stout based on numbers. I will be running it the next time my avenger decides to avenge itself lol

 

[DAMIEN1307]

I will be running it the next time my avenger decides to avenge itself lol

Be sure that you give your Avenger the local suicide hot line number...lol.

 

[sherron82]

This is correct how ever port timings may vary and viability is contingent on your skill level and tool availability(not guaranteed a bolt on solution). However mine appears to be pretty stout based on numbers. I will be running it the next time my avenger decides to avenge itself lol

You said you use the ms380 right?

 

[CuriousJojo100]

Before and after pics of exhaust port. Slight improvement on low to midrange acceleration under WOT. Noticeably less throttle required to get up to cruising speed (roughly 38mph). I will be doing my homework on using a degree wheel. My next step is to purchase a dome piston and replace the head. I’m definitely trying to save this motor before it grenades itself. I did notch the woodruff key that holds the magneto and retarded the timing as far as it would go to establish a baseline for ignition tuning. It now runs VERY SMOOTH. I lost a little low-end power but I noticed midrange gains. I’m not touching it again until I replace that piston and put more miles on it!