Syncing Carbs

[ventureohio]

I am Syncing my carbs on my 85 Venture Royale. Got 1&2 dialed in and 3&4. Now according to the link here:

http://www.venturerider.org/forum/showthread.php?t=495

It says to then sync 2&4 on the first Gen which is what mine is. Now the problem is that #2 is pulling way more vacuume than 4 and I cannot even get it close. Anyone else ever had this and if so, what do I need to look at. Thanks Guys.

 

[GeorgeS]

On left side, Use the Single Sync Screw, to match Aft Cylinder #1 to Fwd Cyl. #2

 

#2 is the Master,

 

Now set the idle speed with idle master set, Under the Left Fwd Carb, ( The Screw with Plastic Knurled Knob.

 

OK, now on right side match the Fwd Sync Screw (#4 Carb ) to the Left Side .

 

 

Now, Match the Aft Carb on the right side to the Fwd Carb on the Right.

 

 

One more thing, Be sure you have 1/16 to 1/8 inch of slack in the Throttle Pull Cable !!!!

 

 

Now, Reset you master Idle to 900 RPM.

 

Now repeat the process. And fine tune it.

 

Now slowly raise RPM to about 2500, and see how they match up ( SLOWLY!! )

 

Do not confuse the Master Idle adjust with the 3 Sync Screws. !!!!!!

Edited June 2, 2009 by GeorgeS

[skydoc_17]

Hey Jerry,

Check out this thread, it has pics and a step by step on the First Gen. Carb. Sync.

By the way, nice bike you have there!

 

http://www.venturerider.org/forum/showthread.php?t=35274

 

Hope this helps, If not PM me.

Earl

[ventureohio]

ok so when you say,

 

now on right side match the Fwd Sync Screw (#4 Carb ) to the Left Side,

 

is that matching #4 carb to #1 or #2 carb on the left?

[GeorgeS]

You want to get them all the same as the master.

 

Make sure there is some slack in the Pull cable.

 

match 1 to 2.

 

Now match 4 to what the average of the left side is.

 

Now match 3 to what u just set 4 to,

 

Now all 4 should be about the same ( you will never get them EXACTLY the same)

 

Then repeat the process to Fine tune.

 

then, check them at about 2500, If big difference there, then try to average out the difference.

 

 

You will get the Hang of it !!

[ventureohio]

Thanks Earl for the comment on my bike, only paid $500.00 for it, and rode it to my house. That is an awsome link with pictures. with everyones suggestion, I should have it in know time at all.

[Bob Myers]

On the second gen I have been working on I sync carbs with my mercury vacuum gauge. Idles fair, has no low end power. Once you get underway it picks up and runs better, with a definite vibration in the windshield/handlebars. After checking the sync 3 times and concluding it was as close as possible, .05mm difference in volume, I stuck a long phillips in the side bag and rode off. After riding about 5 miles I pulled into a drive and tweaked the left/right adjustment. Hmm, better off idle responce, better smoother acceleration, to off the side I went again. After I repeat this about 10 times, the bike idles smooth, pulls away on all 4 cylinders and has almost zero shake in the windshield/handlebars when you hammer it. Out of curiosity I put the merc gauge on it again. It was so far off it should not have even ran. 99rstd, 1,500 milles on the clock

[GeorgeS]

On the second gen I have been working on I sync carbs with my mercury vacuum gauge. Idles fair, has no low end power. Once you get underway it picks up and runs better, with a definite vibration in the windshield/handlebars. After checking the sync 3 times and concluding it was as close as possible, .05mm difference in volume, I stuck a long phillips in the side bag and rode off. After riding about 5 miles I pulled into a drive and tweaked the left/right adjustment. Hmm, better off idle responce, better smoother acceleration, to off the side I went again. After I repeat this about 10 times, the bike idles smooth, pulls away on all 4 cylinders and has almost zero shake in the windshield/handlebars when you hammer it. Out of curiosity I put the merc gauge on it again. It was so far off it should not have even ran. 99rstd, 1,500 milles on the clock

 

Sound like sombody before you was tweeking the SYNC Screws, " With out a Vaccum tool " hooked up. ! In other words they were way out of adjustment.

 

I would, Reset the Idle mix jets ( 2+ 1/4 turn CCW ) then replace plugs, then Drain the carb bowls, Check the throttle pull cable for 1/8 inch slack, -- Then set the Main Idle adjust to about 800 rpm. Then Start over to do the Sync Proceedure.

 

Also, just in case the previous guy, really screwed it up. Set the 3 Sync Screws, to " Just Makeing Contact " before you start.

[Bob Myers]

There was no previous guy. The bike is basically a brand new 99 model, with only 1500 miles on it! i rode the bike about 5 miles 8 years ago and it wasn't "exactly right" then, and then it sat for 8 years in a heated garage without being started. I pulled the carbs, soaked and cleaned varnish and dried gunk out of them. When i reassembled the pack of 4 I did just what you describe, sort of. I used a round gage and set the butterflies at .090" with the carb that has idle screw as master. When I fired it up it would run good on left bank, but no heat on the right, vacuum gage was wthin 1.5mm from low to high,if you revved it up a bit it would smooth out somewhat and start heating right cylinders. I surmised from that there was still gunk in the idle circuit. I pulled the carbs again, and soaked the carbs again for the right side. repeat with .090" gage for bench set on butterflies and install. No difference. I ran a couple cans of seafoam through the tank and it is getting better. Weird part is where I did what I described as just randomly turning the sync screws, and it getting smoother. Yes, Iknow it aint supposed to work like that. To check my mercury gauge I fashioned a dual t fitting and pumped it down with a handheld vacuum pump. All 4 colums pulled up dead even as they should. With that I am reasonablt sure my gauge is not weirding me out.