Carb Synchronization And New Timing Belts - How to get Great Results (Hint: CHECK EVERY VACUUM HOSE CONNECTION)

[Winger1957]

I learned a lot yesterday about tuning a GL1000. I bought mine in pieces from a dishonest seller about four years ago, and generally rebuilt everything except the engine and the wheel/head bearings. I learned more about motorcycles rebuilding from my sellers hatchet job (he was trying to build a bobber) than I ever learned in some 50 years of reading about and riding motorcycles. Truly, if you buy a bad one, rebuild it. Take your time, buy the parts (unless you can restore the part) read the service manual (free download), review the parts manual (free download) and when you have to replace a broken part, go ahead and remove whatever part is next to it, or nearest to it, and clean or restore or replace that part, too. Clean everything as you work. Check for loose bolts and nuts. And check for loose vacuum tube ends.

About one month ago I had to replace my timing belts. They had about 25,000 miles on them and I was 15,000 miles overdue. But I run GATES belts on my GL, and the two belts I had on my GL had appx 25,000+ miles on them, yet still looked very good. See image below.

When the GL1000 manual was written, belts were much weaker than they are today. Modern belts, especially brand-name top tier manufacturers make very durable belts.

But back to the sync. Essential to a good sync is the perfect alignment of the timing marks on the timing belt pullies. That little iron dot of an alignment mark is very important and you must line the dot up perfectly with the timing mark. Below you can see my timing marks in alignment on my primary belt drive pully.

So alignment on BOTH pullies is critical. You must align them perfectly. Perfectly. Not close. And here is how you easily do that...

I use my vise grips with some tape over the jaws. The vise grips stop the compression-driven rebound of the primary pully, and the tape keeps you from marring the back portion of timing belt cover. You will not tighten your vise grips very much. Just enough to stop your pully from spinning away from you and losing your timing mark alignment. See the photo...

In the photo I still have to loosen the vise grips and align the marks, but I had my camera in my hand so here is your vise grip shot. Using the vise grips makes aligning the left-side belt super simple, too. Just rotate the pully with your hand until it aligns with the marker, and slip the belt over it after you put the left-side belt on the center drive gear. Make sure that center belt drive gear is pointing up and is on TD Center.

I also replaced the springs and the two tensioners. All springs/tensioners were functional but all were 47 years old so out with the old.

Remember, tape your vise grip jaws so that they do not scratch. Clamp just strong enough to freeze your right-side pully. The pressure required is surprisingly light. Start light, not heavy.

Gotta go. My son is standing here telling me that I am not "ready". One last thing: 2oz of Marvel Mystery Oil per five gallons of Ethanol Free gasoline. Always. Do this and your afterburners will always fire at full power.