i have a Axial 28 spec 1s, i have about 2-1/2 gallons on it and its running good.

my question is, can i run it with out any insert in the carb for more power ?
it came with a 7.0 and 8.5 mm restrictors if i remember right.

i have always run that engine with the larger insert(8.5mm) and power has been good but if i can get some more it would be great !

thanks for your time,

Impala

I have a couple of questions before I and others can help. Whatkind of vehicle is thismotor in? What % Nitro are you running? what pipe and clutch do you have? You want more? bottomend topend how hot is your motor how good is your tune up? I have more questions then answer now! uc

You might get a bit more power if the larger insert is restricting airflow through the carb but a carb needs a certain amount of restriction to allow it to draw fuel from the tank (with the help of muffler pressure). Without any restrictor (insert) it'd be relying more on tank pressure to feed the fuel which could cause some tuning issues below full throttle. A regulated pressure fuel pump might solve the tuning issue but you'd probably need a carb that's designed for the pump. There's no harm in taking out the restrictor though and giving it a try, if it won't hold a tune then put the restrictor back in .

im running the axial 28 in my LST2 , dynamite long life alum shoes , lst xxl tuned pipe , 25% byrons fuel , its tuned pretty good but if i can get more out of it i wont say no !

downunder , sounds true , the throat of the carb would be too big for the fuel flow the pipe can supply, i will try it when i get some weather hotter then -15c and if it doesnt run right or need a lot of tunning ill put the insert back in


thanks

Impala

I don't use a restrictor and it holds a tune no problem. It is in a Savage X SS.

crazykat , nice to hear that , i cant wait to try it and see if theres a noticable difference !

ok , i went for a little bash session since the weather wasnt too bad

with out the restrictor in the carb it had a lean bog at WOT and was revving high after WOT passes

the weather was about -5c and my tune was allready pretty rich from the last time i took it out in -10c
so i tryed leaning it a bit, it was stalling at WOT and revving a lot after WOT, i tryed more rich and it was bogging at high speed and ran like crap

ill put the bigger restrictor back in and keep it like that until its dead

i like this engine but im not sure if i will rebuilt it when it will be dead because the piston/sleeve is expensive and for a couple more dollars i can get a complete losi 454 on ebay

Hhmmmm.... sorry to hear that. Did you try richening the low speed needle? When mine revs high after a high speed run, i richen the low speed and it does the trick. I have never had a high speed bog with this engine. temps are usually between 210-230 after a speed run. and i am using an OS A5 plug.

hum, actualy i didnt try richening the low speed because it was kinda loading when idling and leaned it a bit.

how's your needle on yours ?
my middle screw is still at stock settings/flush and my low speed is leaned about 1/4 - 1/2 turn (i tune more with the high speed depending on the weather, maybe 1 - 1 1/2 turn lean)

I will have to check the low speed needle but I dont touch the middle needle at all. How is your idle? Fast, or slow? How long does it take for you to get a good idle after a high speed run? 5 sec? 10 sec? 20 sec? Try opening the idle gap and richening the low speed needle.

between 5 and 10 sec.

should i go richer on the LSN than stock setting ? or put it back at factory setting

cause its leaned only by about 1/3 turn ...

My only experience with carb restrictor was on a NTC3. It came with one. Removing it really woke up the engine. I think the restrictor might be good on short race tracks as it makes it easier to control. But it's a lot more fun with it out.

what type of tuning did you have to do to gain performance ?

Honestly, I don't remember having to re-tune it, although I suppose I tweaked it a bit.

I see the insert doing the same thing as if one was to limit the opening of the throttle. I suppose it could affect air velocity and affect things, but not that I could tell.

I"m not familiar with your particualr engine, but I"d play with the tuning a bit more (with the restrictor out) before I resigned myself to using it..

Yes, try richening the low speed. Let us know if that works.

allright next time i have some nice weather i will try some more tuning without the restrictor.

thanks everyone for your help/info...

problem solved ! i just sold it !

a guy wanted it for 120$cnd and i paid it 145$cnd if i remember right. so i lost 25$ for bashing the living **** out of it for 4-5 months.
i liked that engine but didnt like the carb/needles.

so now i need a engine for my lst2. i will probably get a losi 454 because i got one for 120$shipped for my lst xxl.
i didnt broke-in the 454 in the xxl yet because i still need steering servos and tx/rx for it.

but because i only heard good things about them i will be looking for another one... thanks for all your time and help/info !

Oh no! Now we'll never know if improved performance could be obtained by removing the restrictor.........sigh.

oh well......problem solved and the moral is "there's more than one way to skin a cat"