Carb Sync...Again

[oldfaithful]

If this has been asked already, I'm sorry. I searched and didn't run across this particular question. I have an 84 VXVZ12, and after a year of working on the bike it's running pretty well. The problem is that I can sync the carbs and it will purr like a kitten, but after a couple days of spirited riding it's running a little bit rough. Not enough to suspect anything new, so I just sync it again. Then the cycle repeats. Any ideas why? Anyone else have this issue?

[GeorgeS]

Check the clamps below, and above the carb bodies,

Remove air cleaner, make sure the Arrows are lined up.

Also check the intake manifolds for cracks and leaks.

Check the two bolts that hold each manifold onto the cylinder heads.

( there are rubber O-rings where manifolds mount to heads. and they can leak )

 

Check all the nuts and bolts, holding the Carbs onto the Mounting brackets, make sure

everything is tight.

 

Be sure to Lubricate, all of the Throttle Linkage assemblies, and lubricate the throttle

plate shafts going thru each carb.

 

Have you ever lubricated the throttle cables ?? Might help.

 

when you do the carb sync, check for Adjusting for the Minimum Pull Cable, Slack Adjustment. Be sure you have 1/16 to 1/8 inch of slack in the pull cable.

 

I found over the years that I had to Re-Sync my 89 at least once a year, always needed some re-adjustment. but not to bad. Not enough to notice while actually driveing the bike.

[oldfaithful]

Thanks for the suggestions. Good ideas, and a vacuum leak is a likely candidate.

 

Before I go thru all the effort to replace the manifolds, has anyone else had a problem like this and found the manifolds to be the source...or cure?

 

Thanks!

[Trader]

Check the clamps below, and above the carb bodies,

Remove air cleaner, make sure the Arrows are lined up.

Also check the intake manifolds for cracks and leaks..

 

Arrows? What arrows?