Predator 6.5 hp 212cc help

Ilk8tnaty

New member
New to the karting world. Got my son into a stock engine class on a 1/4 mile track. We have had all sorts of problems. We run a 12 tooth clutch, 35 chain, 60 tooth sprocket. We have unhooked the governor but not taken it out. We have had some 19-20 sec lap times but as the night goes on the hotter it gets the more problems we have had. Karts would go 6-8 laps then die. Start right back up and go again for about same amount. We thought the mufflers were over heating the tanks so added straight pipes. Worked for a week or so then back. Brand new motors out of box doing it. Thought has tank was vapor locking so removed gasket on gas cap. Thought ethanol in gas was issue so tried race fuel. Any ideas?
 

racing promotor

Moderator
Can't help you with motor thought's, BUT a 12 front driver on a 1/4 mile track your WAY out to lunch even with a 60 rear your over turning it with RPM. Is it dirt oval ? Since you say for your son did you have to put a plate in it as well ? The gearing being that far off could be the problem since you unhooked the governor.
 
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Ilk8tnaty

New member
Can't help you with motor thought's, BUT a 12 front driver on a 1/4 mile track your WAY out to lunch even with a 60 rear your over turning it with RPM. Is it dirt oval ? Since you say for your son did you have to put a plate in it as well ? The gearing being that far off could be the problem since you unhooked the governor.

This is an asphault track. Could you explain over turning it? What kind of plate? New class to all of us.

Reading through some of the other posts say to drill three 1/8 holes in gas cap? Some say to take vent hose from valve cover and plug it with a bolt?
 

racing promotor

Moderator
Even on asphalt IF it's an oval and indeed a quarter mile track for the 60 rear to be close you would be on like a 21 driver maybe even a 22 to keep rpm around 5100, by plate meaning are they requiring a restrictor plate, over turning it's RPM 's your trying to turn it way past what's its capable of turning, for that big of a track to keep RPM close with a 12 driver the rear would be like a 30.
 
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racing promotor

Moderator
Now usually most tracks oversize the what they advertise them at so I would not count on there 1/4 mile being correct either, do you feel it's that big ?
 
1/4 mile about same size as normal school track and yes it's that big.
Then you are WAYYYYYY off on gear at 12/60. We run that on about a 1/8 mile track and turn 5500 with a plate, 6400 without. A plate is a restrictor plate that goes between carb and head to cut back on power, red, green, purple blue is the colors they require.
 

racing promotor

Moderator
1/4 mile about same size as normal school track and yes it's that big.
For a 12 driver to be correct with a stock predator it would have to be real small track 12th mile & less, we have a fast momentum small 1/8 mile here and guy's are using 17 & 18 front drivers.
You really need to get a tach on kart, but until then try at least a 20 front driver with that 60, as far as a motor issue you may still have something else going on as well.
 
For a 12 driver to be correct with a stock predator it would have to be real small track 12th mile & less, we have a fast momentum small 1/8 mile here and guy's are using 17 & 18 front drivers.
You really need to get a tach on kart, but until then try at least a 20 front driver with that 60, as far as a motor issue you may still have something else going on as well.
Are you using 219 chain on the ones you are calling out 17/18 drivers for 1/8 miles?
 
We run a place they claim is a little shorter than an 1/8 we run a 12/60. I don't think I could fit a 80 to go with a 17, think it would be draggin the ground. Maybe its a lot shorter of a 1/8 lol
 

racing promotor

Moderator
We run a place they claim is a little shorter than an 1/8 we run a 12/60. I don't think I could fit a 80 to go with a 17, think it would be draggin the ground. Maybe its a lot shorter of a 1/8 lol
It would have to be shorter than 1/8th unless you cannot create any momentum at all, If everyone just went with a 12/60 you could be gear bound and not realize it, have you ever tested other gearing I've helped guy's that have pulled a bunch of teeth and gained R.P.M. I also see your turning 6400 r.p.m is that on a stock predator ? If so I'd say your getting false reading.
 
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It would have to be shorter than 1/8th unless you cannot create any momentum at all, If everyone just went with a 12/60 you could be gear bound and not realize it, have you ever tested other gearing I've helped guy's that have pulled a bunch of teeth and gained R.P.M. I also see your turning 6400 r.p.m is that on a stock predator ? If so I'd say your getting false reading.
We are kind of high jacking this guys post. I'm gonna bow out and just say ours is smaller than an 1/8 by a good amount.
 
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