Shovelhead idle issue

[Toucan]

'76 shovel chop/S&S Super E. Runs fine when riding down the road but when I pull in the clutch and close the throttle the revs hang. Im assuming this is either due to a sticky throttle cable or intake leak. Is that a correct assumption? Could it be anything else?

At idle it likes to die, it'll hiccup a few times and then I to blip the throttle to keep it going but other times it just randomly dies. Previous plugs were fouled bad so I leaned out the carb via idle mixture screw. Currently waiting for it to cool down a sec to pull the plugs and check. Then I rode it and it kept dying at stop lights so I increased idle speed screw but that has no effect on it dying or not dying. Any ideas on whats wrong and solutions are much appreciated as its my first shovel and Im pouring over the service manual as well. Cheers.

[Tattooo]

'76 shovel chop/S&S Super E. Runs fine when riding down the road but when I pull in the clutch and close the throttle the revs hang. Im assuming this is either due to a sticky throttle cable or intake leak. Is that a correct assumption? Could it be anything else?

It could be those and a few others...... I like fixing one thing at a time..... It sounds like you have a plain now get to work.......

One thing though...... Does the throttle not go back on it's own??? You say you close the throttle????

Have you ever bothered to oil your throttle cable????? Or cleaned out your carb??? You know rebuild it???

Trash in tank???

And on and on........

[Dragstews]

It sounds like you have a plan now get to work.......

.../// https://youtu.be/EnsVmPHbQT0 \\\...

...

[Toucan]

It could be those and a few others...... I like fixing one thing at a time..... It sounds like you have a plain now get to work.......

One thing though...... Does the throttle not go back on it's own??? You say you close the throttle????

Have you ever bothered to oil your throttle cable????? Or cleaned out your carb??? You know rebuild it???

Trash in tank???

And on and on........

Throttle closes on its own. Maybe I should have said release the throttle coming to a stop. Oiling the cable is on my to do list. Single cable, no return cable.

Carb was disassembled, inspected and given the ok in April before purchasing.

Tank looks good peeking in with a flashlight from what I can see. I have an inline fuel filter, probably wouldn't be a bad idea looking at that.

Anything else?

[misfitJason]

Intake leak

[Toucan]

Intake leak

Was going to use the propane method to check. Would an intake leak cause random stumble and dying at idle?

[Tattooo]

Was going to use the propane method to check. Would an intake leak cause random stumble and dying at idle?

Sometimes........ Not likely but sometimes..........

What do your plugs look like???????? That will tell you a lot believe me..........

[Toucan]

Sometimes........ Not likely but sometimes..........

What do your plugs look like???????? That will tell you a lot believe me..........

The plugs were fouled, black and gunky. Leaned out the idle mixture screw and went for a ride, pulled the plugs and they looked way better so Im interested to see how they look after putting more miles on them. Bike still wants to hiccup and die at stoplights though.

[Tattooo]

The plugs were fouled, black and gunky. Leaned out the idle mixture screw and went for a ride, pulled the plugs and they looked way better so Im interested to see how they look after putting more miles on them. Bike still wants to hiccup and die at stoplights though.

Put in NEW plugs ride it for at least 15 miles and post pics.............

[Toucan]

Put in NEW plugs ride it for at least 15 miles and post pics.............

30 miles on new plugs.
Front plug




Rear plug

[Tattooo]

Looks good to me, Just a little rich......

I don't see an intake leak...........

[JBinNC]

Fat and oily. Typical shovel as Tattooo asserts. But you can have an intake leak and sooty plugs, they are not necessarily mutually exclusive.

Before you start dealing with your possible carb/intake issues, as discussed above, get your ignition RIGHT. That is motor tuning 101. Since you are a newbie by your own admission, post up the type of ignition you have, and those here with experience of that particular type will walk you through it.

As far as checking for intake leaks with propane, because the back of the air cleaner is there close to the intake, it is easy for the propane to find its way into the carb, and give you a false result. Your '76 should have orings for intake manifold to head seals, and these are very reliable. Unfortunately, many shovels have been fitted with the later band seals, which are problematic and have a relatively short life (4 - 6 years, as opposed to indefinite in the case of the orings).

It will be interesting to see how a novice works his way through tuning and repairing with this problem.

Jim

[Tattooo]

I'm gonna go out on a limb and say there is no intake leak as both plugs look the same........ But you do need to check it to be sure.........

[JBinNC]

I'm gonna go out on a limb and say there is no intake leak as both plugs look the same........ But you do need to check it to be sure.........

I'll join you on that limb, but the OP needs to start with the ignition.

Jim

[Tattooo]

I'll join you on that limb, but the OP needs to start with the ignition.

Jim

That would be a great place to start..... But I think he has got it fixed by tighten up the acc pump.....