Carb Syncing with the Morgan Carbtune
I lost my digital camera a few weeks ago, hence the few posts, but luckily the iPhone takes okay photos. Here is the unboxing of the Morgan Carbtune. It comes with everything you need: The Carbtune, several hoses, and some black plastic adapters.
I’m sure that these little plastic adapters would have worked just fine, however, following the wisdom on the SOHC4 forums I picked up some brass adapters that were supposed to be more efficient in more ways than one.
As you can see the brass adapters come in two sizes, long and extra long, to easily reach the inner two carbs. I suppose the length is the main advantage to the much smaller black plastic adapters. They went on easily and came off just as good. I imagine that being brass they will last much longer than the plastic ones.
All four carbs had a small vacuum plug which was essentially just a short 6mm screw. Step one was to unscrew the vacuum ports and screw in the brass adapters on all four carbs.
The length of the brass adapters made easy to fit the black hoses on as well.
Here is a shot of all four adapters in place.
Step two: As per instructions on the Morgan Carbtune Website cut 10cm from the end of each black hose.
Step 3: cut restrictor tube into four equal pieces.
Assemble restrictor tube pieces in between black hose pieces.
10cm cut end goes to brass adapters at the carbs.
Motion Pro carb sync tool. It’s simply just a long screwdriver augmented with a long socket driver for unlocking, adjusting and locking the carb synch screws.
I have had nothing but good experiences with Motion Pro. I got my brass adapters and the carb sync tool from them.
Here is a shot before the tank was pulled. I used a camera tripod to hang the Morgan Carbtune to be able to see it better.
Ultimately, this is how I set up my carb sync procedure: I got two basic run of the mill cinder blocks and stacked them on top of each other. I then placed the blocks as close as I could to the bike, even folding up the foot peg to get the bricks closer to the frame. After the bricks were in place I sat the tank on them with the petcock facing toward the frame. One of my fuel hoses (carbs 1 and 2) was close enough to connect to the petcock, the other fuel hose I had to extend using a fuel hose extension adapter.
Carb syncing was fairly easy to setup but doing it was another story. Carb syncing is not really a science or an art, its more of an acquired skill. To much precision is involved in balancing four carbs as well as taking into consideration locking down the lock nuts once its synced. You could have the carbs sucking perfectly but then once you tighten one of the lock nuts they are out of sync again. For the unapt it becomes a trial and error learning experience. Unlike the stories I’ve read on the forums about vacuum syncing being a piece of cake and a relatively short process, my syncing took place over two mornings just to learn the process and get it right.
I did notice both an audible tactile difference when the carbs were finally in sync and as you can see from the video below, my carbs were desperately out of sync. This is not something I want to do again and again, in fact, I’ve grown to somewhat dislike carburetors and see the appeal of digital fuel injectors.
austincaferacer 