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Discussion Starter #1
Hi guys, in need of some advice, I've had my old shovelhead block totally stripped and rebuilt, but I only had an old SU carb which was pants, so I managed to get hold of a new (off a demo bike) Fatboy carb, but struggling to get it running. My petcock is a straight through, so fuel delivery is ok, and presume as its new that the jets are ok, had it ticking over but won't rev...
Any thoughts and advice most welcome
785902
 

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Manifold leak?
 

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Best carb overall for that engine. IMO take carb apart to check jets, float level etc. Don't presume anything, make sure for yourself.
 
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Enlarged the pic and noticed the throttle cable is installed wrong, notice the spring dangling down !
 
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Discussion Starter #5
Checked the manifold & it's seems tight, & hoping as it's a new carb the jets etc are ok, but know what your saying about assuming things so it's a 'to do' thing, & Schmidty I know lol, saw it and thought bugger, schoolboy error 🙄
 

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Discussion Starter #6
Obviously it has a vacuum outlet too, but nothing to connect to, should I blank it off or leave open ?
 

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Cap it off if you are using points.
 
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Look to see if the slide tries to raise when you twist the throttle. If no, manually (screwdriver,etc.) raise the slide a little at a time as you twist throttle (running of course). If it revs when slide is moved, you have a problem with the slide diaphragm.
 

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When ya get the bowl off check that the slow jet is at least a #46, better yet a #48 for that engine. Then remove the main jet holder and drop the needle jet out. Confirm the needle jet gets reinstalled right side up, concave end up,
Finally check the tip of the float needle, there shouldn't be a groove or ring in the tip. That can happen when a new carb gets banged around with an empty float bowl. Then verify float level prior to reinstalling the bowl.
Lifting the slide with a finger then let it freefall it should float down not drop down with a thud. Floating down verifies there's some vacuum behind the slide.
Also there should be no open ports on the carb body behind the slide tower. There's usually 1 port which is the vacuum port for a VOES switch, in your case that port should be capped off.
Post up a vid with sound when ya get that Shovel running. Love the Shovel sound.
 

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Discussion Starter #11
When ya get the bowl off check that the slow jet is at least a #46, better yet a #48 for that engine. Then remove the main jet holder and drop the needle jet out. Confirm the needle jet gets reinstalled right side up, concave end up,
Finally check the tip of the float needle, there shouldn't be a groove or ring in the tip. That can happen when a new carb gets banged around with an empty float bowl. Then verify float level prior to reinstalling the bowl.
Lifting the slide with a finger then let it freefall it should float down not drop down with a thud. Floating down verifies there's some vacuum behind the slide.
Also there should be no open ports on the carb body behind the slide tower. There's usually 1 port which is the vacuum port for a VOES switch, in your case that port should be capped off.
Post up a vid with sound when ya get that Shovel running. Love the Shovel sound.
Thanks for the advice, hopefully I can get to it before the weekend & spend some time checking it all over, & correctly fitting the throttle cable 🙄 hopefully I will get it sorted and fired up, I'll definitely put a video up once it's running 👍
 

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Discussion Starter #12
Look to see if the slide tries to raise when you twist the throttle. If no, manually (screwdriver,etc.) raise the slide a little at a time as you twist throttle (running of course). If it revs when slide is moved, you have a problem with the slide diaphragm.
Wil do, cheers👍
 
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