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Carb removal

  • Thread starter Thread starter redstedman
  • Start date Start date
What are these direct lift carbs that are being referenced here? I'm not familiar with this.
 
There are carbs that lift the slide up mechanicaly, usually by a cable, and carbs that use vaccume to lift the slides. A vaccume lift slide or "Constant Velocity"(CV) carb requires vaccume from the manifolds and an airbox to work. Some try to put pods on CV carbs. Some even claim that it works well. The truth is it will not work well even if it appears to work. A dyno test will prove it. There will be flat spots and very poor mileage. Pods look cool but they don't work on cv carbs.

OK, now that I've opened up a can of worms whats next, an oil thread?
 
redstedman said:
My 78 GS has direct lift carbs & pods:lol:Easy on easy off
Click to expand...
All of my 850s have CV carbs and stock airboxes. :D

I'll wager they are even easier than your '78. :p

Usually less than five minutes, on or off.

But, ... with a stock setup, it's not necessary to remove them very often.

Nuitdevotremort said:
What are these direct lift carbs that are being referenced here? I'm not familiar with this.
Click to expand...
They are referring to the VM-series carbs that came on the four-cylinder GS bikes before 1980.

The CV-style carbs have a butterfly throttle that is directly controlled by the cable, but has a variable venturi that is controlled by the vacuum that is created by air rushing under the slide. This gives more-consistent jetting for the variable street environment.

The VM carbs have slides that are the throttling mechanism, and they are lifted by the cable. While they do have the potential of quicker response, they also have a very pronounced tendency to fall flat on their proverbial faces if lifted too quickly. This is the primary reason the move was made to CV-style (that's "constant velocity") carbs, to satisfy the tighter EPA rules at the time.

.
 
Hmm, so I've understood these types of carbs allready... Are you calling the non vacuum carbs the direct lift carbs?
 
Yes. The slides are directly connected to the throttle cable. CV carb slides are not directly connected to the throttle cable.
 
redstedman said:
There are carbs that lift the slide up mechanicaly, usually by a cable, and carbs that use vaccume to lift the slides. A vaccume lift slide or "Constant Velocity"(CV) carb requires vaccume from the manifolds and an airbox to work. Some try to put pods on CV carbs. Some even claim that it works well. The truth is it will not work well even if it appears to work. A dyno test will prove it. There will be flat spots and very poor mileage. Pods look cool but they don't work on cv carbs.

OK, now that I've opened up a can of worms whats next, an oil thread?
Click to expand...

Right guys, now I have read this I just want to be totally sure about my carbs. I am about to remove them for cleaning and was going to put pods on in the winter but may well do it now.....ARE these carbs in the photo below OK to run with pods????? and if I am going to get rid of the air box can I get it out/off before the carbs to allow room for removal of the carbs??? I believe the bike I have is a GS1000EN (1979)...there are some odd things with this bike, the tank is a 1980 ET so just want to be sure.
Any help always appreciated guys

Cheers

RB (Greenbraes)

bikepics-2295995-full.jpg
 
Those are VM carbs...the direct slide types, off the 70's bikes.
My personal favorite
 
Greenbraes said:
Right guys, now I have read this I just want to be totally sure about my carbs. I am about to remove them for cleaning and was going to put pods on in the winter but may well do it now.....ARE these carbs in the photo below OK to run with pods????? and if I am going to get rid of the air box can I get it out/off before the carbs to allow room for removal of the carbs??? I believe the bike I have is a GS1000EN (1979)...there are some odd things with this bike, the tank is a 1980 ET so just want to be sure.
Any help always appreciated guys

Cheers

RB (Greenbraes)
Click to expand...

Your bike isn't odd - it's a UK spec model that falls slightly out of synch with the US models. It's a late EN.

Those are VM carbs and they'll run fine with pods, though you will need to tune the carbs to suit. You need to remove the carbs before you can get the airbox out.

Don't sling your airbox whatever you do - they're getting valuable over here now as there don't seem to be that many kicking around.
 
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