Shvlhd Motor Starts but Dies out Immediately
#1
05-09-2008, 09:05 AM
Shvlhd Motor Starts but Dies out Immediately
Hello,
I have a 1983 shovelhead. Upon turning the key and engaging the starter, the motor kicks in, turns and exhaust out but immediately dies out. I've check to make sure gas is in the tank, and petcock is set to on. I just recently rebuilt the S&S E carb but not sure it the accelerator pump is working correctly upon start up. There is gas squirt coming out of the accelerator tube but I'm not sure if it's set correctly because it will squirt inconsistently. Question: Upon start up, is the accelerator tube supposed to be squirting consistently? I'm not too sure what to look for to diagnose this starting problem. Any help will be greatly appreciated. You guys know your stuff.
Thanks
I have a 1983 shovelhead. Upon turning the key and engaging the starter, the motor kicks in, turns and exhaust out but immediately dies out. I've check to make sure gas is in the tank, and petcock is set to on. I just recently rebuilt the S&S E carb but not sure it the accelerator pump is working correctly upon start up. There is gas squirt coming out of the accelerator tube but I'm not sure if it's set correctly because it will squirt inconsistently. Question: Upon start up, is the accelerator tube supposed to be squirting consistently? I'm not too sure what to look for to diagnose this starting problem. Any help will be greatly appreciated. You guys know your stuff.
Thanks
#2
05-09-2008, 09:44 AM
Road Warrior
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#3
05-09-2008, 03:38 PM
RE: Shvlhd Motor Starts but Dies out Immediately
Accelerator Pump: The function of the accelerator pump is to improve throttle response when rapidly opening the throttle at low rpm and to aid in cold starts. S&S sets the accelerator pump adjusting screw for maximum volume (all the way out) to aid during initial start-up after installation. Turning the screw inward (clockwise) decreases delivered pump volume. Turning it outward (counter clockwise) increases pump volume. Adjusting the Accelerator Pump: [ol][*]Warm engine to operating temperature.[*]Turn pump travel adjusting screw inward until screw contacts pump actuator arm. This shuts off the pump. Caution – closing adjusting screw with excessive force can cause irreversible damage to screw threads in carb body.[*]With engine warm and at idle, blip throttle and note throttle response.[*]Turn pump travel screw outward or counter clockwise about 1/4 turn at a time and recheck throttle response until engine no longer hesitates. This is usually about two turns out.[*]Minimum pump travel is recommended to conserve fuel, prevent spark plug fouling, and curtail black smoke from pipes when blipping throttle. Black smoke is usually an indication of a rich condition or excessive accelerator pump travel. [/ol]
Some Performance Notes: [ul][*]To be sure idle mixture adjustment is correct; always check with fully hot engine.[*]If popping or backfiring through air cleaner occurs upon taking off, this indicates a lean condition requiring that a larger intermediate jet be installed (one size larger) (size is stamped on bottom of jet).[*]When fine tuning the intermediate circuit, it is best to turn off the accelerator pump completely. It can mask jetting symptoms.[*]Whenever the intermediate jet is changed, the idle mixture should be readjusted.[*]If engine backfires or sputters in carburetor or breaks up and or dies during acceleration, increase or richen main jet size.[*]If engine runs flat and sluggish or blubbers, or will not take throttle, decrease main jet size.[*]Always use an insulator block between carb and manifold. If not the heat transfer from the manifold to the carb may cause a temporary rich condition at idle and low speed rpm. [/ul]
Some Performance Notes: [ul][*]To be sure idle mixture adjustment is correct; always check with fully hot engine.[*]If popping or backfiring through air cleaner occurs upon taking off, this indicates a lean condition requiring that a larger intermediate jet be installed (one size larger) (size is stamped on bottom of jet).[*]When fine tuning the intermediate circuit, it is best to turn off the accelerator pump completely. It can mask jetting symptoms.[*]Whenever the intermediate jet is changed, the idle mixture should be readjusted.[*]If engine backfires or sputters in carburetor or breaks up and or dies during acceleration, increase or richen main jet size.[*]If engine runs flat and sluggish or blubbers, or will not take throttle, decrease main jet size.[*]Always use an insulator block between carb and manifold. If not the heat transfer from the manifold to the carb may cause a temporary rich condition at idle and low speed rpm. [/ul]
after the engine is warm do you experience the same thing or is the engine not running at all?
there are several things that could cause intermittent pump squirt. low float settings adjustment to the pump and having the check valve installed correctly for starters.
let us know what you find.
#4
05-09-2008, 04:01 PM
RE: Shvlhd Motor Starts but Dies out Immediately
Thanks Rodney. You always have great advice. What's happening with my issue is that the motor starts but quickly dies out. I've notice that the butterfly has a small gap between itself and the venturi opening. Will that cause the engine to die out? Also the accelerator rod or pump rod may be sticking. Will this cause the carb to flood and kill the engine?. I was going to take off the carb and see what I did incorrectly. I'm getting close to starting this puppy. I'm very anxious and really want to get this baby on the road. I'll let you know what happens next.
#5
05-10-2008, 08:35 AM
Road Warrior
#6
05-10-2008, 12:06 PM
#7
05-15-2008, 06:10 PM
RE: Shvlhd Motor Starts but Dies out Immediately
Update on this problem. The issue was not related to the carb (which incidentally was rebuilt once and taken apart again by me to see if I rebuilt it correctly) but the key switch wiring which naturally did not include clear wiring instructions. I'm using one of those marine or boat switches which does not require a relay. It's a automotive spring-like switch which fires up via the key or pushing in the key on Start mode. What I did wrong was have the solenoid wired thru the circuit breaker when I should have wired the solenoid directly to the key switch. Problem solved. She fires up so easily and sounds purrrrrrrrrrrrrfect. Thank you all for the input. On the road again.Trending Topics
#8
05-19-2008, 03:27 AM
#9
05-19-2008, 11:30 AM
RE: Shvlhd Motor Starts but Dies out Immediately
hey Bad,
Here's a pic of my bike. I'm opted for the switch because of it's simplicity and ease of wiring (yeah right!). I like the features on it like the push button start on the key switch itself and also the fact a relay was not needed. I'll send you another pic of where the key switch is located on my bike.
[IMG]local://upfiles/44527/32CBE076937F460DB82144AF02425F74.jpg[/IMG]
Here's a pic of my bike. I'm opted for the switch because of it's simplicity and ease of wiring (yeah right!). I like the features on it like the push button start on the key switch itself and also the fact a relay was not needed. I'll send you another pic of where the key switch is located on my bike.
[IMG]local://upfiles/44527/32CBE076937F460DB82144AF02425F74.jpg[/IMG]