Tuning an ESP 27.2 engine

[AlvaSpeed]

I have a ESP 27.2 4 bolt with a 813 carb.


My low speed needle is 7/8 of a turn open. Way less than the 1+ turn used by most.


If I open the Low speed more than one turn the engine bogs.


The high speed is about 1 1/4


Why is that?

 

[kryptonite]

all motors tune diffrently. don't go by other user settings or sugjested manufacter settings. (sounds scary right?) your carb settings all depend on the porting, the type of porting as well as the porter, also if you have a machined head, the type of manfold you are running, crank- wether its stuffed or not, and of course exhoust. oh ya. and fuel,(octane/ethanal or not) the the type of 2 stroke oil(synthetic or not) and your ratio. and all that will also change with the type of running you do. if you do say beach running or sand dune running, you'll find a richer setting is what works. if you do short course running, you'll need to lean out a tad so you don't foul out.


bottom line is you should tune your rig so it runs right and you have proper plug color.. plug color is all that matters if your not sure, start back with factory settings. depending on your motor, it may not even run at factory settings. but start there. adjust the low end so it idles and accelerates ok. then put it on a stand. hold the throttle at WOT while leaning out the high speed till it reaches max rpm. from there, turn it out 1/8 of a turn. now your ready to start tuning


-body off


-plug accesable


-clean plug with wire brush


the point of this is to get the plug to a nice chocolate brown. in order to do this you must do high speed passes while keeping the rpm's up. no idle time as that will give you a false reading. if you have a kill switch, use it.


do 4-5 high speed passes and quickly kill the motor on the 5th pass(kill switch?) pull the plug and see what color it is. if its black then lean it out in adjustments of 1/16 of a turn(high speed needle) keep doing that until you get a nice plug color of light chocolate brown. if it starts getting grey then your too lean. sometimes this may take some time. it takes me about half a tank. once you get your plug color good, bash it out for the rest of the tank and at the end, check your plug as it will change colors with your driving style. once its tuned, your good for a while as long as you don't change any motor components. i will try to find the esp tuning guide for you as well..

 

[AlvaSpeed]

Kriptonite,


I tune the high end by the plug color, with a kill switch. No problem there.


I was worried about the low end.


I have a ESP 27.2, 813 carb, billet air filter, DDM side pipe, lightweight flywheel and the car does not take off with authority like my 23cc did with the same accessories but with the stock carb.


On the clutch department I have a 8k spring.


Not sure if the clutch is grabbing too low that it makes the engine bog.


I have ( but not tried) a HPI high response clutch and a lauterbacher 4 shoe.


I am going to tune the low end on a stand to take out some of the clutch factor and go from there.


What do you think?

 

[Sprint 77]

the stock carb will give you better off idle kick than the 813. The 813 works well for parking lots and wide open areas. if you run a track conditions or do lot of slow getting ready for jumps then gas it go back to the 668.

 

[Clubin]

I know this isn't the same engine, but I have a 27.2cc O'Neill it doesn't have very good low end, it is a mid to high RPM engine. That would be my comparison to a DDM ported 28.5. Hope that helps. You could get it to a higher RPM quicker by installing the HPI High Response clutch and spring, that might get it past the dead spot.


I am running a 813 on it too.

 

[Sprint 77]

I don't disagree with you mooman I guess I mis spoke or was just trying to be curtious. The 813 does have the squirter affect so those of us that ran the 668 for so long that can not get out of the habbit of blipping the throttle a little all the time have low end load up issues. thus causing a rich mixture of fuel and getting a hessitation on low end.


I was not wanting to let him know his index finger was to blame but way to catch it Mooman

 

[Sprint 77]

Also you could have a high end pipe on a motor ported for low end they all have to match the driving conditions your wanting to get optimum performance.

 

[kryptonite]

i think alva has a vid of it, but im not sure. maybe he can post it? that will greatly help out.. if its the same vid i saw, it really lags on the bottom