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Old 02-26-2009, 07:51 AM   #1
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Default GRP .21 Carb Restrictor ?

I am running a GRP .21 Silver top all stock.. My mill has plenty of power I was wondering how much run time I would stand to gain by changing the size of the carb restrictor. I would really like to hear from some people that have played around with some different sizes.

I just looked at mine and it came with a 7.0. Do I have to use a GRP?

Right now with a race tune on the richer side I am getting about 7 mins run time with a JP3 pipe
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Old 02-26-2009, 07:58 AM   #2
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Originally Posted by robbdny View Post
I am running a GRP .21 Silver top all stock.. My mill has plenty of power I was wondering how much run time I would stand to gain by changing the size of the carb restrictor. I would really like to hear from some people that have played around with some different sizes.

To be honest I am not even sure what size my motor came with I dont see it any where in the manual.

Right now with a race tune on the richer side I am getting about 7 mins run time with a JP3 pipe
It comes with a 7mm stock. I have been using the 8mm in a .21 tuned and averaging 10-11 min per tank in a truggy. I also have a powerhouse modded GRP .21 with the 8mm insert and that engine was averaging 11.5 min per tank in a 8T 2.0. How much fuel has been through the motor. It sounds like it is not broken in all the way yet. These engines take awhile to break in.
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Old 02-26-2009, 08:10 AM   #3
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It comes with a 7mm stock. I have been using the 8mm in a .21 tuned and averaging 10-11 min per tank in a truggy. I also have a powerhouse modded GRP .21 with the 8mm insert and that engine was averaging 11.5 min per tank in a 8T 2.0. How much fuel has been through the motor. It sounds like it is not broken in all the way yet. These engines take awhile to break in.
I have about 1.5 gallons through it. Remember to mine is the non tuned version. From what I have been told the biggest difference in the tuned to the non tuned is run time and slightly more top end
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Old 02-26-2009, 12:03 PM   #4
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I have about 1.5 gallons through it. Remember to mine is the non tuned version. From what I have been told the biggest difference in the tuned to the non tuned is run time and slightly more top end
yea but you still should be gettin 8.5-9 min on a tank
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Old 02-26-2009, 01:14 PM   #5
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I'll go ahead and tell ya; on the JP3 you're not going to see mega-mileage.

Look into the GRP 2053 or even a Nova 9853 or 9901 and see if you don't pick up a little.

The one guy in my area that runs a GRP uses a 6mm restrictor (on a buggy). Fine for most tracks, but runs out on the top end of bigger tracks.
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Old 02-26-2009, 01:20 PM   #6
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I'll go ahead and tell ya; on the JP3 you're not going to see mega-mileage.

Look into the GRP 2053 or even a Nova 9853 or 9901 and see if you don't pick up a little.

The one guy in my area that runs a GRP uses a 6mm restrictor (on a buggy). Fine for most tracks, but runs out on the top end of bigger tracks.
a dynamite 053 is a great pipe for the grp as well
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Old 02-26-2009, 02:43 PM   #7
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Use a dynamite 053 with the 7mm insert and you should be getting around 8:30 to 9 minutes in race tune. By the way it's a sweet little engine you'll be glad you bought it. jp3 is killing the mileage!
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Old 02-26-2009, 03:21 PM   #8
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Default pipe and restrictor

So what you guys are saying is a smaller restrictor alone is not going to make any sort of noticeable difference. But switching the pipe and the restrictor will make a small diff maybe an extra 1min or 1.30 min run time
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