Smolik minarelli hybrid motorized bicycle kit.

[Cannonball3]

I think rod length is as important as stroke. I have a 40mm stroke pk80 that has a short rod. The piston winds up way more than 2mm in the hole at tdc. Am building with a Zeda. Its a 40mm long rod. Not my favorite engine, but it works with the conversion.

 

[Bizal]

I think rod length is as important as stroke. I have a 40mm stroke pk80 that has a short rod. The piston winds up way more than 2mm in the hole at tdc. Am building with a Zeda. Its a 40mm long rod. Not my favorite engine, but it works with the conversion.

This might be a stupid question, but shouldn't a 40mm rod be a 40mm stroke?
Mines a 40mm rod and I just assumed it was the same for the stroke, but after talking to u guys I measured it and it was 40mm

 

[Cannonball3]

My Zeda has the long rod, I believe its 115mm overall where the short rod engine can be 110mm. A way to tell is to measure from the top of the rod journal to the top of the rod At tdc. Long is around 85mm short is around 80. The Zeda measured right at 84 so its a 40mm long rod. My PK is a 40mm stroke short rod and wouldnt work. Came up short even with a low hole piston, plus the Minarelli piston hit the crank before reaching bdc. The Zeda worked perfeclty. Im using the 40mm engine spacer.

There are so many variables among these engines between stroke, rod length, and piston height(low, high hole) you really have to know what you have. I bet most vendors dont know what they are selling at least on ebay. Also there are different jug heights. Confused yet?

 

[Cannonball3]

I couldnt link this for some reason. Go to pk80engines.com there is a lot of good info. Find the page with the engine
geometries. It should clear things up a bit.

 

[DAMIEN1307]

This PDF tech manual of the differences between PK80, GT5, and Zeda 80, (short rod, long rod, high wrist pin, low wrist pin, etc.), might be helpful as well to "clear things up a bit"...DAMIEN

 

[Cannonball3]

Thanks Damien! Good stuff.

 

[wan37]

K, thanks for the info
I'm gonna sping for the genuine mikuni.
I'm gonna upload pics as I build to get some input.
The worse part is waiting for parts

Where you getting the genuine mikuni at? Just curious.

 

[wan37]

I think treatland would be my place to get it.

 

[Bizal]

This PDF tech manual of the differences between PK80, GT5, and Zeda 80, (short rod, long rod, high wrist pin, low wrist pin, etc.), might be helpful as well to "clear things up a bit"...DAMIEN

That was very informative and really cleared things up for me.
I thought I had a 40mm, but turns out I have a 40mm rod that is a 38mm stroke.
I order the 40mm stroke minarelli cylinder kit. I was gone by a new bottom for the build anyway, but I'm glad I did. From reading that the 40mm stoke makes more power. Wich is what I'm after.
Now I got to find a zeda 80 bottom some where. The only problem I see is a lot of these places that sell these motors send u something different then what u ordered.

 

[Bizal]

I think treatland would be my place to get it.

Yea, I think so. I don't trust ebay all tho there's some one on there now that's selling one for $90
And has real good reviews. Like a 99.4 with 10,000 sales. Wich is good I think.
I think I seen it on treatland for $100 I think, but then shipping