Need Help Diagnosing

[Rikugun]

Before you tear into the electrics, consider rule 1 of Vision ownership....  "If it's running poorly, it's the carbs - it's always the carbs"  :P  :laugh: Well, 99% of the time anyway.  :)

I'll assume you've checked compression and valve clearance and know the top end is healthy.
Remove the YICS and cap of the engine ports.
Ensure the carb fuel level is correct and non-rusty gas is in the carbs.
Wear safety glasses  :D and test for air leaks with carb cleaner - pay special attention to the throttle shaft ends (4) and the manifolds and their mating surfaces to the head. Check at idle and 3k RPM.
Assuming their are no air leaks, adjust and sync the carbs.

If it still runs poorly it might be something other than carbs but I'd still be suspicious of them....  ;D

[Conrad]

If you have checked the float bowl using either of the two methods mentioned above since you re-installed the carbs, then look to the electrics. You may have dislodged a connection, during the dismantling or reinstall of the carbs, which is now working intermittently

The other thing, did you make sure that the right  jets went in to the correct carb? For most of the jets it doesn't matter, but the main jet usually has different sizes in each carb. Mine has 122.5 on the front and 127.5 in the rear. Size is stamped on the top. Depending on your eyesight, you may need a magnifying lens to see. If your mates were helping you, they may not have noticed the difference.

I'll be sure to check the jet sizes asap. 

Before you tear into the electrics, consider rule 1 of Vision ownership....  "If it's running poorly, it's the carbs - it's always the carbs"  :P  :laugh: Well, 99% of the time anyway.  :)

I'll assume you've checked compression and valve clearance and know the top end is healthy.
Remove the YICS and cap of the engine ports.
Ensure the carb fuel level is correct and non-rusty gas is in the carbs.
Wear safety glasses  :D and test for air leaks with carb cleaner - pay special attention to the throttle shaft ends (4) and the manifolds and their mating surfaces to the head. Check at idle and 3k RPM.
Assuming their are no air leaks, adjust and sync the carbs.

If it still runs poorly it might be something other than carbs but I'd still be suspicious of them....  ;D

I checked for leaks at idle, could it be possible I missed something because I didn't try 3k rpm?  When I have some spare time I'll try syncing the carbs again.

[Conrad]

Well, it seems that the latest cleaning fixed my problem!  After adjusting the pilot screws and syncing the carbs its running way better now.  Thanks everyone for your help.  Hopefully my bike will last longer than a week before I need to clean the carbs again...

[Rikugun]

Nice going! Glad it's sorted out and just ni time for riding season.  ;)

[Tiger]

Conrad...When you have had the gas tank off, did you remove and clean the petcock & screen as well as flush the gas tank out before re-installation and fill up with fresh gas??... and after all your hard work doing your carb clean, re-installation and carb sync......did you remember to install an in-line gas filter by chance?? If not, prepare for another carb clean shortly!!


                  8) ....... TIGER .......  8)

[Conrad]

Conrad...When you have had the gas tank off, did you remove and clean the petcock & screen as well as flush the gas tank out before re-installation and fill up with fresh gas??... and after all your hard work doing your carb clean, re-installation and carb sync......did you remember to install an in-line gas filter by chance?? If not, prepare for another carb clean shortly!!


                  8) ....... TIGER .......  8)

Cleaned the petcock, forgot to flush the tank...  I did get a filter though!  One of the first things I did.  How do I flush the tank? 

[Rick G]

,remove the tank and plug up the  petcock opening. then add a half gallon of solvent  or paint  thinner.  and a hand full of  nuts and bolts . shake the hell out of it , while rotating it . use a magnet to remove all the hard ware and  rinse with clean gas. Drain through the petcock opening . as the lip at the cap will prevent complete emptying. (it is a  '83 you will need to remove the  fuel gauge sender and plug that opening too!)

[Conrad]

,remove the tank and plug up the  petcock opening. then add a half gallon of solvent  or paint  thinner.  and a hand full of  nuts and bolts . shake the hell out of it , while rotating it . use a magnet to remove all the hard ware and  rinse with clean gas. Drain through the petcock opening . as the lip at the cap will prevent complete emptying. (it is a  '83 you will need to remove the  fuel gauge sender and plug that opening too!)

Ok, thanks! 

[Jimustanguitar]

If yours has an old tank liner in it that won't come out (Kream seems to be the worst), use acetone as your solvent and throw in a handfull of drywall screws since they're sharp and abrasive.