What?? Another Carb Question!!

[lsutley]

I have been diligently reading all the carburetor posts and articles hoping that I would discover the secrets to remedy the problems with mine. I have only been partially successful thus far.

 

I did find vacuum leaks between the boots from the air-box to the top of the carbs. Took it all apart, cleaned and reassembled. Started up and there was still a leak, a boot had slipped off of the carb. I have redone this process several times and the boots will not stay on top of the carbs when enough force is applied to stop the leaks.

 

Is this a problem that is familiar to anyone?

[Snaggletooth]

I'm going to bring up one thing on this. During reassmbly of the carb rack did you use an assembly plate to make sure that all four carb bodies were dead flat on the bottoms?

 

It is important to make sure that all points on the axis lines are spot on level and straight. This effects all your common adjustments including sync.

 

But, from my experience with the carbs on mine, I had trouble the first few times getting my boots to seal up properly until I made an assembly plate set up and got it all lined up right. Leads me to belive that some issues with the boots must be caused by misaligned carb rack adjustment.

 

Just my two cents as there are so many other problems for leaks but if the bodies aren't seating right I'd check the rack alignments.

 

Mike

Edited July 9, 2012 by Snaggletooth

[Yammer Dan]

:sign yeah that::sign yeah that::sign yeah that:

[lsutley]

Thanks guys. I did not pull the entire rack, only the intake boots, where the leaks were detected. After the reassembly the RPM's, with the previous idle setting, increased by 500. Reset the idle to 1000 and tried the spritz, with Zep I.D. Red, again and the RPM's increased when the boot to carb area was targeted. The rack could be misaligned from previous repair processes and could certainly be a possibility. Other "adjustments" that have been found have lead me to believe that all were not approached with the fix it once mentality.

 

After reading all the comments, regarding the problems created by the vacuum leaks, I wanted to eliminate any chance that that might be the source of a problem before re-syncing the carbs. They were synced last year and the RPM's would continuously rise as high as 3000 (without changing the idle setting). Each time the idle was returned to the correct range, for a sync operation, and adjustments resumed, the idle RPM's would rise until all settings were finally dialed in with all the vacuum readings equal and in range the idle stop screw was set to the 1000 point. Bike ran better but not really well.

 

Decided that the vacuum leaks should be eliminated before trying to re-sync the carbs and now another problem has been detected. One of the boots was found to have previously slipped when I did the first leak test and I cannot seem to eliminate the cause. If the consensus is that the entire rack is misaligned, then out they come for a trip to the granite surface plate.

[Squidley]

Les,

 

If someone other than yourself had the carb bank off from the top portion of the intake manifolds, they might not be all the way on. I have taken several carb banks completely off 1st gens and you really have to put some downward pressure into push them down onto the tops of the manifolds for them to completely engage.

 

I dont have picks of it, but there is a shelf on the bottom of all 4 of the carbs, that when it's installed properly will sit flush on top of the carb manifolds. I have fixed many of them where the previous owner didn't have them pushed down all the way. If this isn't right it will screw all sorts of things up. Hopefully Dingy will see this thread and have pics of a set of carbs sitting correctly (he has more pics of naked 1st gens than Carters got Little Liver pills)