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Discussion Starter #1
I tried to synch the carbs on my '83 Shadow but the intake vacuum on one cylinder (the rear) is extremely low. When I disconnect the manometer, I can feel and hear the air sucking into the tube for the front cylinder, but the rear has very little suction. Any ideas would be appreciated.
 

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Sync

You may have an air leak in the rear cylinder. Make sure that the rear carb is mounted correctly with no leak. Other than that you may need to perform a leak down test on the rear cylinder to see how healthy it is.
 

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It would help to have some more info. 83 Shadow...what model/cc/mileage, etc. Could be carbon build up on the valves, cracked valve/seat, pinched vacum hose/s, pinched gas line, loose carb boot clamps, idle screws "bottomed out". The list is long but you gotta start with the basics and go from there. But we need alittle more help from ya.

Bullzeyet
 

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Discussion Starter #4
It's an 83 750 with 25k miles. I've checked the carb mounting. I thought it might be a leak in the connection between the carbs and the head so I switched them but no change.
 

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I'd still do a compression check as mentioned above.

Carb linkage broken? Carb diaphram torn/pin-holed?? Carb slides moving??

Your air cleaner dirty or changed lately? Or was the bike "sitting" for a long time?

Just some thoughts and areas to look over.

Bullzeyet
 

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Discussion Starter #6
Thanks, Bullz. I'm thinking compression test as well. The carb linkage is fine. I checked out the diaphram but didn't see any damage. The slides move ok, the air filter is new, and I rode the bike all summer.
 

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Not sure what else to suggest at this time. Maybe head gasket, a piece of carbon is "stuck" in the valve seat area or a lifter not "pumping up", broken/mushroomed valve stem top. :roll: Just start checking stuff. We'll still be here. :wink:

Bullzeyet
 

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Have you checked the REAL simple? Could one of the vacuum taps be plugged or gummed up?

Gumpy
 

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I was kinda hoping he put a toothpick/paper clip in there to "see/feel" IF it was plugged/gummed in some way. Should have made that more clear to Wolfman...sorry. :oops: Maybe he got a "fur ball" in there.....lot's of stuff flyin' around on the road. :wink: :lol: :lol:

Bullzeyet
 

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bullzeyet said:
I was kinda hoping he put a toothpick/paper clip in there to "see/feel" IF it was plugged/gummed in some way. Should have made that more clear to Wolfman...sorry. :oops: Maybe he got a "fur ball" in there.....lot's of stuff flyin' around on the road. :wink: :lol: :lol:

Bullzeyet
Bullzeyet,

We have a real problem with 'mud daubers'. Those things will build a nest in darnedest places.

One of the lessons they taught me was to really look way down in the pitot tube of an airspeed indicator system!

John
 

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Yeah, we have those things down here too. Pesty devils. Or even those "wasps" building their "paper apartments" anywhere they damn well please!!!! :twisted: :lol: :lol:

Some of these "problems" are realllly tough to "figger out" without being able to get your hands, eyes, ears around the bike to help. But I suppose it's the "new" way to the future. Where's my hammer...I gotta go hit something!!! :twisted: :shock: :lol: :lol: :lol:

Bullzeyet
 
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