Possible starting problems with alky

[modracer47]

We have switched from gas to alky and it takes our engine about 10 or so tries to run under idle.
The engine starts, runs for 5 seconds or so and stalls (this is at 2000 - 2500 rpm).
There is no problem getting the engine to start, just to continue running.
My friend/crew chief upped the jet size to 93/94 from, I believe upper 80's, and it is still
a "problem".

Is there something we are missing?

I appreciate your help.

Thanks.

[JustAddDirt]

alky

This is an alky carb right? (just asking to make sure with that small of jet in it to start with 80ish)
Has it backfired through carb?
If so change power valves.
Start with your idle air adjustments 1.5 turns out from fully closed.

[SnapOn35]

We shut the fuel off after the races are over and let the carb run out of alcohol and when we get back to the shop we fill the front bowl with gas so when we start it the next time it fires right off and continues. Not sure if this is your problem or not but its a idea because alky doesnt seem to wanna fire at first.

[dirttrackrocker]

What type of regulator do you have?? How much fuel pressure do you have at idle??

[modracer47]

I have talked to my crew chief and here are the answers to the questions.

The carb is a C&S Alky. Jets were sent at 91Primiary/90Secondary. We changed to 94's for both.
It has not backfired.
The air adjustment is at 1.5 turns from fully closed.
The regulator is a KSE with the pump being a KSE dual fuel/PS.
At idle the pressure is approx 3 lbs.

We did talk last night about filling the bowl with gas because the alky is cold and too rich and with gas it is consistent to run and it would warm the engine quicker.

Thanks for your input.

[TeamGRT12x]

When the engine fires, keep it running with the throttle... alcohol engines are cold blooded.

Get rid of that C&S... I owned two of them in 09 and they were a nightmare.

[joeltjen]

starting

when i start my alky motor , first i give the idle screw about 1 1/2 turns, give it a healthy shot of gas down the carb with a "ketchup" bottle , start cranking the motor over and after about three or four revolutions turn the switch on, should light right up. as it warms up you'll have to adjust the idle screw back down or it will idle about 3500 rpm . takes a while for the engine to build heat even with a thermostat. we use low tension rings so that makes it even more cold blooded. once you have some heat in it ,it should start the rest of the night. in the fall specials when it gets down in the 40's it'll take gas before the feature too

[AH55]

Get rid of that C&S... I owned two of them in 09 and they were a nightmare.

Same experience here.....my C&S was terrible!

[cavemod]

I had the same problem I tried using a brasswell carb and no help bought a c&s aeresol billet and a mechanical procam pump along with a c&s mechanical bypass that hooks to the secondary throttle shaft it it works fine and its fool proof..If you don't prefer to go that route check metering block for obstructions and loose throttle shaft bores(fuel seeping out on baseplate)warped base plate or intake mounting area.jetting does sound kind of lean I was at 98 with my modified flow c&s.Any fuel dripping out of the booster while engine is trying to idle???If its the same kse setup you used with gas change the pill thats in the pump.does the motor stay running when you turn the idle up to over 2500 or does it still die once in a while??

[Egoracing]

We always raised the idle when firing our motor up or it would die. We got a piece of plastic that was the right thickness and made it where it would go into place between the screw and stop to hold it slightly open.

[JustAddDirt]

carb

I have talked to my crew chief and here are the answers to the questions.

The carb is a C&S Alky. Jets were sent at 91Primiary/90Secondary. We changed to 94's for both.
It has not backfired.
The air adjustment is at 1.5 turns from fully closed.
The regulator is a KSE with the pump being a KSE dual fuel/PS.
At idle the pressure is approx 3 lbs.

We did talk last night about filling the bowl with gas because the alky is cold and too rich and with gas it is consistent to run and it would warm the engine quicker.

Thanks for your input.

I have had a C&S Billet Aerosol, and it was probably the best alky carb I ever owned.

What is your fuel level in bowls when this is happening?
Could it be running out of fuel?
Could floats be set too high, and fuel is poaring in through boosters? (venturi)
at 2000ish RPM it should still be running off the idle passages, and not the jet (fuel coming in through boosters (venturi), basicaly you should not see the fuel poring down on the throttle blades yet.
If it is check float level, and change powervalves to a higher number.
Not faliliar with the belt drive fuel pumps, I assume they build more pressure with rpm.
Have you tried a bit more fuel pressure?
I ran a mechanical pump and held a 8-9 psi fuel pressure all the time.
Also check top of intake with a straightedge to make sure it is flat.
Also check carb base for cracks on corners.
Does carb or baseplate have any vaccum ports that do not have plugs on them?
I seem to remember my c&s having a small port or two on baseplate that required a vaccum cap.
try to spray brake parts cleaner, or carb cleaner around carb base when running to see if RPM's change.

I have done what egoracing has done with a small zip tie wrapped around throttle rod.
insert between throttle adjust screw and linkage for a faster idle.

while trying to get it to run, push down on the front accelorator pump to see if it helps the situation, or hurts. That would tell you if you need more fuel or less.

Also put a 180 thermostat it in. I have always ran a thermostat, and it always warmed up well, and never had any alky in my oil cause motor is always up to a good temp when running.

If you need to further assistance you can PM me and I will give you my phone #.
Be glad to try to help

[TeamGRT12x]

You haven't said if you're using the throttle at all to keep the engine running. You're not going to blow the thing up.

Idle it up a few turns of the screw, or simply use the throttle to keep it running.

Justadddirt- What alcohol carburetors have you owned? C&S is a great drag race carburetor no doubt, but definitely behind on the oval track stuff.

[JustAddDirt]

You haven't said if you're using the throttle at all to keep the engine running. You're not going to blow the thing up.

Idle it up a few turns of the screw, or simply use the throttle to keep it running.

Justadddirt- What alcohol carburetors have you owned? C&S is a great drag race carburetor no doubt, but definitely behind on the oval track stuff.

Silver stacked Billet Aerosol. Bought it new in 1996, and used it unitl 2009.

[TeamGRT12x]

I was asking, what OTHER carbs have you owned to compare to?

Did you ever try the 6 jet version they offer?

[JustAddDirt]

carb

I was asking, what OTHER carbs have you owned to compare to?

Did you ever try the 6 jet version they offer?

Also had a stealth carb.
It was good, but throttle response just wasnt as good a C&S
Never had the 6 jet set up, figure the standard set up worked well for me, no need to spend more money on somthing that I did not feel I needed.

I think alot boils down to what parts you have under the carb. That makes a big difference in the way a carb preforms.