107 CID Intake Manifold Question...

[localboy]

Aloha,

Working on my boss's BG.

Not sure what model it is, but I believe it's either a 2005 or 2006, with a 107 S&S engine.

Noticed on the intake manifold, a vacuum fitting, toward the front head, that seems to be missing a rubber [vacuum] cap. With the engine running, there is vacuum and when we cover the fitting, at idle, the engine dies.

Anyone know if this fitting is supposed to be capped [with a rubber vacuum cap], and why it dies and what needs to be done [adjusted]]?

Thanking you all in advance!

 

[kgamsg]

I've got two of those on my 107ci, 03 Chopper; I capped them both and cured my backfire on decelation issue...not sure why yours dies...there are quite a few folks on here that have the knowledge to answer though.

 

[V]

If its a 05 or 06 with stock engine its a 117 cu in. If the carb and air cleaner is stock it should have a cap over the port. If you are covering this and it dies seems like you're not getting enough air.

 

[stlmikie]

My 107 has one. It is capped.

 

[Killerdog]

mine is a 2004 with a 107 and mine is capped also...when it started to dry rot and crack it started to suck air and miss..once i got cap replaced it cured my miss

 

[localboy]

Killerdog...

You are correct! My Boss said it's a 2004...

I replaced the missing vacuum cap and no more popping - back firing! It would no idle so I adjust the idle screw just under a quarter turn and she now idles and sounds much better.

Next question is - why does all the lights flash on the speedo head?

Thanking you in advance!

 

[localboy]

THANK YOU ALL FOR THE RESPONSES!!!

 

[Justintime]

Killerdog...

You are correct! My Boss said it's a 2004...

I replaced the missing vacuum cap and no more popping - back firing! It would no idle so I adjust the idle screw just under a quarter turn and she now idles and sounds much better.

Next question is - why does all the lights flash on the speedo head?

Thanking you in advance!

The tach lights flashing means your idle is under 900 rpm. Mine flashes un til the bike warms up.

 

[V]

Killerdog...

You are correct! My Boss said it's a 2004...

I replaced the missing vacuum cap and no more popping - back firing! It would no idle so I adjust the idle screw just under a quarter turn and she now idles and sounds much better.

Next question is - why does all the lights flash on the speedo head?

Thanking you in advance!

What Justin said below 950 RPMs your tach will flash. Should turn it up a bit as this also means potential low oil pressure.

 

[localboy]

Thank you very much V and JUSTINTIME!!!

I'll make the idle adjustment as needed.

Thanks again ALL & Ride Safe!!!