Milling the head of an 86 spree

Does your Spree/Elite already run great, and you're trying to make it quicker/faster? Need a monster motor swap? Discuss your ideas here.

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circusracer
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Post by circusracer »

mccain wrote:Mines an 86 with 4300 miles on it. My moms boss gave it to her and she gave it to me, so I nick named it the Honda free. All I had to do was rebuild it.

I flooded the motor with the 68 jet, I'll try it again after I port it.
Thats good that you have the 1986, that means you should have the dome style piston and not the dished. Your ahead already.
84,85,86 sprees: Intake mod, drilled pipe, .020" milled 1985 head, dome piston, 2mm raised exhaust port, sb50 reeds, 34mph average.
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Lunytune
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Re: Milling the head of an 86 spree

Post by Lunytune »

mccain wrote:Well if I can take away .020" for next to nothin' then I don't think im gonna' pay someone to mill a perfectly good head down.
Depends on your objective. The advantage of paying a machinist to put it on a mill instead of hand lapping is that it will be true. It takes a steady hand and skill for hand lapping. Milling it down will increase compression ratio and power. How much is questionable. Remember though, increasing compression ratio requires higher octane as a rule.
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mccain
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Re: Milling the head of an 86 spree

Post by mccain »

I always used premium gas because I never knew what the scooter needed so I figured better safe than sorry. My neighbor has machinery that will allow me to mill the head true, :D .
The bottom end of the motor went bad so now im rebuilding it. And to reference "circusracer". Your right the piston is domed!
I live my life a quarter pounder at a time, and for those 500 calories or more...im free.
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circusracer
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Re: Milling the head of an 86 spree

Post by circusracer »

mccain wrote:I always used premium gas because I never knew what the scooter needed so I figured better safe than sorry. My neighbor has machinery that will allow me to mill the head true, :D .
The bottom end of the motor went bad so now im rebuilding it. And to reference "circusracer". Your right the piston is domed!
I have a 1985 and a 1984, so I had to buy the domed piston. :mrgreen:
84,85,86 sprees: Intake mod, drilled pipe, .020" milled 1985 head, dome piston, 2mm raised exhaust port, sb50 reeds, 34mph average.
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