Carb sync'ing issues - Advice/suggestions??!!

[tugla]

point being you can do a sync by eye with carbs off or maybe look down when installed to see if one is oit of wack.pretty sure there is a point vacume increases then goes down. you can test by twisting throttle with your sync tool on it will rise higher from 1000 vs 1500....

 

[banff_springs]

Need some clarification here....the forward screw on the right side moves #3 & #4 simultaneously....when you turn that screw only #3 will move and #4 doesn't?? :ummm:

Correct. Forward screw sync's #3 & 4 to #1 & 2 however, #3 SHOULD balance/sync both #3 & 4....and it's not. #3 will sync just fine...#4 won't move at all....

 

[banff_springs]

point being you can do a sync by eye with carbs off or maybe look down when installed to see if one is oit of wack.pretty sure there is a point vacume increases then goes down. you can test by twisting throttle with your sync tool on it will rise higher from 1000 vs 1500....

Yes, found a way to semi-sync while on the bench using two drill bits of same size. Seems to be my best bet as I have the carb's off right now and in pieces.

Will have to be something I tinker with later...my job is getting in the way of my fun....not impressed.....however my job is paying for the parts soooo...kind of a trade off....

Would much rather be riding...that's for damn sure..

 

[banff_springs]

A bent tab might make the linkage off far enough so that you can not get the proper adjustment to bring that carbs' butterfly to close enough to match the other 3 carbs. The little springs in between those carb linkages can prove to be a real PITA while re-assembling also. I've found myself putting them back together incorrectly on more than one occasion, until I figured out what was going on.

After dissassembly of the carb's, I checked the tabs...don't appear to be bent. Yes, I can see putting the springs back in to be a PITA....am following shop manual so, only hope I am doing it right.

 

[banff_springs]

You still have enough time to ride, For me when I syc my carbs had to adjust them along with tuning the idle screw on the lift side under the carbs for all to 4 working together. If I remember right I turn the idle screw out a little because 1" was a little off than the other 3 cylinders. Then touch up the syc on all.

Sweet looking sync....impressive. Will remember that when I go to re-assemble and fire it up and am ready to sync again.

 

[dannymax]

Sounds like the tab/spring/sync aparatus is binding somewhere....has the bike fallen over recently?

Maybe you can turn the forward screw in & out and see what's keeping #4 locked up?

 

[banff_springs]

Sounds like the tab/spring/sync aparatus is binding somewhere....has the bike fallen over recently?

Maybe you can turn the forward screw in & out and see what's keeping #4 locked up?

Bike did get dumped 3-4 years ago prior to me owning it.

Something I will have to try later as carbs are currently in pieces...

 

[06VMAXIMUS]

Doubt its your problem, but its worth mentioning that when you do the final assembly of the 4 carbs, make sure to lay them on something flat and level before tightening the retaining bracket screws. If the carbs look good then it might also be worth doing a compression test on all 4 cyls too....as Mark stated you might have a valve hanging open.

 

[banff_springs]

Doubt its your problem, but its worth mentioning that when you do the final assembly of the 4 carbs, make sure to lay them on something flat and level before tightening the retaining bracket screws. If the carbs look good then it might also be worth doing a compression test on all 4 cyls too....as Mark stated you might have a valve hanging open.

Will have to see if I have a compression fitting that will go that deep. May be a bit of an issue. Good suggestion on having them lay flat however, I have been making that a regular practice so in this case, I'd rule that out. Yes, It was mentioned about valves. May be my next step.

 

[dannymax]

Will have to see if I have a compression fitting that will go that deep. May be a bit of an issue. Good suggestion on having them lay flat however, I have been making that a regular practice so in this case, I'd rule that out. Yes, It was mentioned about valves. May be my next step.

Something like this would work good....Canadian Tire should have a similar kit? It's pretty hard to access those deep holes without something flexible.

http://www.harborfreight.com/quick-connect-compression-tester-95187.html

 

[tugla]

Something like this would work good....Canadian Tire should have a similar kit? It's pretty hard to access those deep holes without something flexible.

http://www.harborfreight.com/quick-connect-compression-tester-95187.html

:rofl_200:

:rofl_200::rofl_200: that's what she said....:rofl_200:

what rpm u checking sync.....try 12-1400 then back at 1000....

 

[dannymax]

:rofl_200:

:rofl_200::rofl_200: that's what she said....:rofl_200:

That's odd....she never had to say that to me!! Bwahahaha! :rofl_200::rofl_200::rofl_200: :ummm:

 

[tugla]

That's odd....she never had to say that to me!! Bwahahaha! :rofl_200::rofl_200::rofl_200: :ummm:

lol:ummm::confused2: think I'm still half asleep hahahah
unk:

 

[banff_springs]

Something like this would work good....Canadian Tire should have a similar kit? It's pretty hard to access those deep holes without something flexible.

http://www.harborfreight.com/quick-connect-compression-tester-95187.html

Will definitely look into this. Besides, gives me another excuse to purchase another tool for the box....unk:

 

[dannymax]

Will definitely look into this. Besides, gives me another excuse to purchase another tool for the box....unk:

I hear that! :clapping:

A good idea to blow out the plug holes before removing the plugs, all kinds of crap can find it's way in them....clear out the drain holes also.

 

[banff_springs]

I hear that! :clapping:

A good idea to blow out the plug holes before removing the plugs, all kinds of crap can find it's way in them....clear out the drain holes also.

Thanks. When I'd ready to re-assemble, I'm going to print off the forum-notes and take suggestions into account. Here's to hoping that it will work "right out of the box".

 

[Mutley]

Did you ever get the the bottom of this Carb 4 being high problem, seems like i have the same issue, 1 -3 sync up just fine but 4 seems alot higher and will not budge,
Haven't really start to diagnose it yet except closing mixture screw full on that cyl does not seem to make any difference so probably start with that first and check spring.

 

[wayne z]

Will have to see if I have a compression fitting that will go that deep.. May be my next step.

The old "shade tree" compression test was to stick a thumb in the sparkplug hole and spin the motor. Good compression would pop your finger off quite dramaticly, and you can feel the difference on a weak, leaking cylinder.

I wanted to test compression on my barnfind Vmax that was dormant for 4 years with the same tecnique

So I dug around in the basement and came up with a short piece of 1/2" cpvc pipe and cpvc cap. I put a patch of duct tape on the cap to help seal, and used the assembly like a long finger to feel the compression. A wooden dowel or anything similar would do.

This might be a low tech way for you to check compression on #4.

I was lucky, because I could see a some nasty gummy stuff on the valves when looking in the ports and was worried about stickey valves, but compression felt strong on all cylinders.

 

[Redbone]

This might work if you want to get a number on your cylinder compression: http://www.harborfreight.com/quick-connect-compression-tester-95187.html

My compression runs from 172 lbs to 176 lbs..

 

[marsmax85]

I had a customer of mine friday give me a 200 dolla tip . She said not to spend it all in one place so I gave the wife fiddy and I am Harbor Freight bound !! Friggen love that store