What carb restrictor are you running? I have been running the 7mm restrictor and a jp-4 pipe and been getting around 11 min on a tank weekly.

ive been using the 6mm restrictor and stock pipe.i love the smooth power delivery but fuel milage is poor.my lowend needle is 3.5 turns out and my highend is 2.5 out.i have my carb idlle gap set at .022.im no newb to racing just this engine has me stumped.

that seems a little lean on the top and fat on the bottom, mine is around 3.5 turns on the top and 2.5 on the bottom, this motor likes to have a leaner low end to make the power, and get good fuel economy

as far as the jx over the grp i dont know, im not the biggest fan of the jx, its kind of a mix match of motors, has the crank from the .28 zx and the engine case, but a piston sleeve and rod that is similar to the vspec but with 5 ports, i run the speed's and the grp, they both work good for me

thanks for the info cjm1126 .ill try your settings and see how it goes.i have a big race this weekend and i want to do a two stop 30 min main.

one more question does anyone make a ceramic rear bearing for the grp

the tuning of this engine is alot diferent than my v-specs.they seem to like more fuel on bottom and leaner on top.

actually, mine were the opposite..you have to tune the lsn first, then the hsn on the GRP's...get the LSN to where the idle is steady (not dropping after a high speed run), and then adjust the idle screw for desired idle speed, then turn on the hsn...if you have the lsn too rich, you will get a lot of flameouts and fouled plugs - also, this engine runs much cooler then others...mine always came off the track around 190-205 or so

i worded it poorly i meant it to be my v-spec likes a richer low end and leaner upper.

You might also try going to a 7mm restrictor. You would think that the bigger restrictor would cost fuel mileage but I actually picked up some mileage going to a 7mm over the 6mm. 6mm seams to choke the engine alot so your in the throttle more. I also know that the jp4 over the pipe in the promo kit seams to help bottom end and also improve run time alittle.

i havent tried the jp4, but i know that the 9853 novarossi, and 2035 associated pipes made a big difference in performance for mine as well, over the grp pipe, and the economy got better, i also found the os p3 plug to work better with the engine

Yea I heard the same thing bout those pipes but I already had a jp4 on my v-spec so thats what i use. I also switched to os plugs ran a p3 for awhile but had some issues with them not lasting long so i went to a p4 and have had the same plug in the motor for 3/4 a gallon or so w/ no problems so far

i looked at the taper angle on p3 compared to grp plug and thought they were different.

now im curious im taking both to work tomorrow and putting them on optical comparator and put my curiosity to rest.ill let all know if taperangle is the same.

someone did a compare of the two with tool and die measuring equipment and found no difference in angle of the two plugs. the P3 was a tad (like thousandths) longer I think. I have been running a P3 since breakin without any problems.

i have been getting around a gallon of fuel out of either of them, the issue's i had with the grp plugs was 3 out of 5 actually worked, 2 of them were bad for the price i was pretty disapointed, i have been using the os p3 in just about everything and they work good

Heres the link to measurements of OS vs. GRP.

http://www.rctech.net/forum/nitro-of...ml#post4398529

Is the associated pipe the same as the Dynamite 053 pipe or the Thunder Tiger 2035 Tuned Pipe?