C51 Kid Kart racing - WHy is my kid's engine so much slower?


Premium User
Ours ran just over 10,500 and was good enough to win us 2 track championships. We locked it down a bit so lil man could flat foot it.
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New member
I am rebuilding my comer, blew a ring at the turkey race...Can someone shed some light on what base gasket to use.


Don't know one builder worth a darn that would freshen let alone blueprint a c50 for 299.00 and I've been racing over 55yrs. Heck nowa days it's gota cost 35 to 50 bucks just to ship just sayin Chuck.


New member
The squish or the power output ?
Port height would change slightly with the base gasket as well .
No engine builder will tell me what to use for obvious reasons but what I got out of him is the less squish the higher compression but be careful not to go to low that you fail tech because of cc’s so I am pretty sure I can go down safely to the .010
He may have just spent a boat load of money to have it refreshed / blueprinted by a professional.
If you have not had this done to your Comer get used to what happened or spend less money and put a 206 on his kart.
You will spend less money buying a 206 than you will having your Comer blueprinted by someone that knows how to make them fast.
Listen to Jimbo. He knows what he is talking about!
206 should be THE ENGINE for all kid classes. Cheapest and easiest engine to own out there.
More than likely you up against some questionable engines. We noticed at our track when tech guy was off that weekend we almost got lapped. When he was there we would finish on same straight away. When we graduated to full size one of our competitors did too. I noticed on here he started selling comer outlaw parts for a friend. Ya right. To run with big boys you got to change piston ring often, check tow, and get axle to spin forever(reduce rolling resistance) , make sure you muffler isnt carboned up using castor oil. Took me two weekends to figure that one out. Take torch heat it up and it will burn out on it's own. Make sure choke is completely off. Burnt twice by this and on and on. Best day of my life when we quit running a comer.


I’m putting on a 79cc clone Harbor freight 4 cycle. I think it was $80. I made a motor mount to fit the 2 cycle frame mount. Next is a clutch guard. Going to start grand daughter. I also found a remote shut down too. Going to leave the governor hook up till she learns and I am ok with her going faster. As with kids. “My kart is not fastest enough”.

The LO206 is a big size motor for a kid kart.
Just as motor 2 or 4 cycle. There is always a way to get in the gray rules to go faster. Those with deep pockets will always win.




alvin l nunley

Premium User
Step 1 = blueprinting does help.
Step 2 = cranking compression pressure is important, check it often. A "good" compression gauge is not cheap, buy a good one.
Step 3 = check to see if the clutch is holding the engine at peak torque on the starts. Really important!!
Step 4 = exhaust gas temperature gauge (EGT) is a "real" tuning helper.
Two karts, side-by-side, going straight, hit the gas at the same time and, one pulls away from the other, can mean several things.
Two of the most obvious are, lack of horse power and/or poor clutch performance. If there's no "gearing" rule, I'd be looking at that too!
You might think that paying to get your engine tested on a dyno is expensive, but, just starting out and testing at the track for all the things you need to test for can be expensive too!
Tuning is tough" (Al Nunley)