Newbie 87 spree exhaust mod ?'s

[HoyerMotorsports]

I've been a lurker on here for a while now. And this is a great forum to
Learn things from. Everyone does a nice job of guiding people through problems or mods.
So I've has this 87 spree for a while now that I use for a pit bike and with the help of this forum, I've kept it running fairly well by diagnosing problems and repairing accordingly.
I get made fun of at the racetrack,(I manage a sprintcar team in Indiana) for riding my spree.
So to give it a little more respect, I've dissassbled the engine, I've done the intake mods and the exhaust mod to the cylinder. I cut the head down .020" and split the muffler and removed all the restrictions.
Heres my question:
When enlarging the exhaust port, I went up 2 ring widths. But mistakenly cut into the bottom of the exhaust port too. Not much, just a few thousandths.
Will this completely change the timing, or will it just make the scoot inefficient?
And, can you put the head on backwards?

[SuprasNsprees]

yes, the head can be put on backwards. it affects air-flow across the top (cooling issues)

[HoyerMotorsports]

Thank you. I wondered about that. So the overhang goes to the front or to the rear?

[Trafficjamz]

Thank you. I wondered about that. So the overhang goes to the front or to the rear?

it hangs over the right side(fan side)

when the piston is at BDC, does the piston clear the ex port?

[HoyerMotorsports]

Hey thank you so much for the reply. Yes the piston clears ex port at bdc. And I'll re torque the head in the right position. Makes perfect sence now that you say it.
Thank you. Thank you!

[HoyerMotorsports]

I got it all back together and it runs GREAT! No jetting issues. Fired up and ran like a champ. I put some oil in the gas to richen the mixture a little for break-in, and let it idle or a few minuets and then ran it down the road at about 15-20 mph for a mile or so.
Then cheked the plug. It was fine. I let it cool and re-torqued the head again.
Then fired it up one more time and warmed it up the same way, then full throttle on the way back I hit 36-37 mph.
Sounded like it was turning waaaay more rpms. Kept waiting for the rod to come through the side of the block. HA!
It's SUPER load and I'm not sure I like it. I might add a sprintcar muffler on the end and see what that does for silencing.
I couldn't have done any of this without the help of hondaspree.net
A million thank yous to everyone that makes this board so great!

Chris Hoyer
Hoyer Motorsports