Homemade Carb Sync Tool

+1 on the Morgan Carbtune. I have one as well. It is a great tool - easy to use and nicely made.

 

I got around to syncing my carbs today. It went very well considering I have never done it before and I used homemade tools. 3 and 4 were pretty close, needing only a little adjustment. 1 and 4 were off quite a bit. 2 and 4 needed just a little adjustment. It took me about 1 hour to build the tools and do the job. I learned a few tricks to make it work with my homemade wrench, such as turning the throttle just slightly to help get better access to that hard to get screw for #2 (which I ended up doing from the right side even though it is more crowded there).

Here is the tool. I used power steering fluid because I had some kicking around. It worked well even though it is clear. I was able to see the levels fine. I would use something a little heavier and darker if I were to do it again though.




Here is my homemade wrench. It is just a long screwdriver with some 1/4 inch socket bits. The electrical tape worked well to allow it to bend around a bit to get onto the sync screw heads better. I would play around with the socket alignment by removing it and turning it one position to help it fit on the screw with its new alignment.


Here are the adapter screws.

 

Some serious Yankee ingenuity here. Thanks for the post!

 

There's lots of McGiver's up here in Canada too, lol. Google Canadian inventions, you might be suprised!

 

An indisputable fact indeed! Robertson drive screw heads beat Phillips heads any day!

 

Did you use mercury? I have to buy it separate for mine (ships to Canada without mercury). I tired using 140 gear oil and carbs 2,3, and 4 (can't hook up carb 1 until i pinch the vacum fuel hose) The oil might be to light because it just kept pulling the oil until it was about to enter the flexible tubes, then i turn off the bike, and wait 5 minutes for the oil to drain back down, but it would take me hours to adjust the carbs this way. Where did yours level off with your VFR700 with the mercury?

 

I know, an old thread, but maybe useful to someone. On my VF500 I used 2 stroke oil the first time in my windscreen washer fluid hose manometer, and November 2021 I used 2T petrol/oil mix (the weather was colder so the oil on its own was too viscous). I used a long screwdriver on its own to turn the adjusters. Very awkward, but not impossible. Actually, only had to turn 2 of them (carbs on cylinders 2 and 3) as number 1 was OK. Density of mercury is about 15 times that of petrol/oil mix.

I have a cramp buster on the throttle grip and used a rubber band on that and the front brake lever to hold the throttle open a bit when accessing the adjusters with the long screwdriver.

I set up a funnel to supply fuel directly to the carbs and plugged the number 1 port when testing the others.

 

I can suggest using engine coolant concentrate; ethylene glycol has a density of 1.1 where petrol/oil is morel likely 0.8.

 

when synching carbs with gauges, it's best to blip the throttle a couple times after each movement of the screws so throttle butterflies settle into their new position better.

 

Good idea. Next time I'll try that.

 

I used a homemade sync tool for a while but I finally just bought a cheap dial type tool. You can get them for $40 or so.