Carb sync... not like riding a bike.

Is it typical from a good bench sync for #1 carb to be way off? #2-4 where in the neighborhood but #1 didn't even register on the motion pro. I did calibrate the tool so I think I can rule that out.

 

Carb #2 is your reference adjusted by the thumb screw. Maybe you can use the long drill bit method to check them on the bike, just don't drop em...

http://vfrworld.com/forums/showthre...ving-me-insane?p=431169&viewfull=1#post431169

 

Thanks, Kenny. Kind of did a lazy dude's carb sync... Bench synced them with a super small feeler gauge (.002), threw them on and ran through the air/fuel mixture screw routine and then took them off and rechecked the butterfly valves. I know that's no substitute for a good vacuum test but man, she started and settled to 1k rpm so nicely and was very responsive on the throttle. I'll have to run it for a while and see how it fairs.
It does have me thinking about a possible alternative setup for easy valve adjustment screw access... a flexible attachment to those valve screws or just a replacement screw (same thread of course) with a flexible extension. I found this pic online...

 

Nope! There is no substitute for lazing up a carb sync. I've tossed the Motion Pro aside for a 4 - gauge setup.

Anyone had any luck with one over the other??

 

Like this?

 

F motion pro, the carb six you got have to be calibrated from the base cylinder every time you use them. What a PITA, at least when they sold Mercury you did'nt have to do this drill. I got a Morgan Carb tool and am happy with it. I read aboot the drill method etc for synching the carbs, what I do is play "peek-ah-boo" with a reference hole in the master carb venturi. I adjust the adjusters on the other carbs based on this reference hoe, it helps to snap the throttle a few times when your doing this and have your reading glasses and a head-light and your good to go. I just did this the other night and am impressed with the idle and low speed ride. Gona put the gauges on them just for shits and grins though down the road. Cheers...

 

yes, sir! I did the air/fuel mix adjustment procedure but without out a tach hooked up so i may need to revisit that. I used the motion pro's 4-1 hose adaptor and ran all hoses from carb #2 back the the new set of gauges to get them synced. Then hooked them up normal and proceeded to have an epiphany whilst burning the back of my hands. When they all fell into the synchronized state you see in the above photo I literally made a "squealing" noise. Thankfully, my girlfriend came home later and confirmed I'm still a man.
Seriously, this has always been one of my big headaches with this bike and I feel much more confident in my abilities.

 

:thumbsup: you think the honda engineers wanted to torture us with burned hands? They must be laughing though, I thought aboot having those long rubber hoses you mentioned to turn the adjuster screws, but just delt with the hand that honda gave us. I did take the PAR air valve sucker things off the bike and ended up using the old hoses with some bolts on the end for the time being, my other bike has screws on the plenums. Cheers and don't let the little woman hear you squeeling like a piglet, thats reserved for harley doodes. ; )

 

I too would like to rid my ride of 20lbs of PAR... How did you plug the holes on the cylinder heads?

 

it may not be 20# but its ugly and complicates getting air box and carbs off. I took a dremel tool, I cut the metal line as close to the plate that bolts to the engine with the two bolts. The front cylinder is easy, the rear is a little more difficult to do, with patience and a some tape to protect any thing that you don't wana scratch you can do it.

I took what I cut off and hacksawed a better cut close to the shoulder, I then went to my neighborhood welder and had him weld up the holes, its perfect and he charged me $20 same as last time, (this is the second one I did.) You can re-use those funky space age heat gaskets when you pull the plates off the engine, just take some care. As far as the air box goes, I got some automotive plugs and plugged the two oot lets on the front of it. I had to JB Weld one of them, same thing happened to me before! Not a big deal, then the two front carbs. My other bike I have bolts with washers in them, this bike I took the rubber line, cut it in two and re-attatched them to the respective carbs, I finished it with a bolt in the end. It proved itself as when you spray carb cleaner near them, there is no fluctuation in the idle. So; there you have it basically, its amazing what they had to go through to put that crap on our bikes huh. I think you might be able to buy those plates but why bother.

I removed the little rubber urinal thats on the rear valve cover to catch errant petrol too, WTF? :loco: who thinks of this chit? Someone with a fetish for toilets? Some poor Japanese engineer is all upset that I removed his urinal creation, only a Honda...

 

I had never heard of the PAR SYSTEM until i was trying to make sense of all the tubing running around the engine and what those two vacuum taps off the front cylinder heads were driving. Correct me if I'm wrong but all that system does is dilute the exhaust a little. Probably to comply with something like carbon parts per million from 12" away from exhaust can. Really... WTFey!

 

I think its when you roll off the throttle after hammer the chit oot of it. The PAR system injects a little air into the system to lessen the richness of the mixture from a fast close of the throttle,?? I could be wrong though. Most bikes have this set up, my Kawi has a reed valve set up on the valve cover that goes to a sucker that gets routed to the air box. This set up has been used for decades, upon talking to a really good source regarding removing this crap, he told me you would really not accomplish anythinhg good, and could in-fact go backwards. In theory you could eliminate this and have it suck off the air box and supposedly, it will free up some HP because the pistons have less restriction. I had a race bike and never messed with it, I do think that I connected the two elbows together with one hose though, (can't really remember.) This was not a viffer though..

Eliminating the PAR thing on these bikes is a no-brainer though. No regrets,

 

I dont know but i hate it! Winter project. Im not messing with her for a while. Did you have to drop the swingarm or anything to get to the rears? Is there any market for the salvageable parts left over on the PAR?

 

I took off the rear wheel and exhaust pipe, that was enough, and with judicial care with my Milwaukee cordless dremel tool with the cut-off wheel it was an ok job. In the past I used a die-grinder which was like carrying my sub compact hand gun in my waist band, (which kinda sucks.)

Only salvageable parts are what you cut off bascially, some hoses and that stupid air valve thing. I save hoses, the other crap I bin, told my wife who wants to save the world aboot the whole removing "emissions" stuff and was surprised I did'nt get a rash of chit. Anyway, take your time and enjoy your bike, you can always remove that stuff.

 

Think the 4th gen Anti-PAIR would work on a 3rd gen?

https://tpoparts.com/cat093/index.php?route=product/product&path=91_99&product_id=52

 

I just beat my record and balanced the VFRs' carburetors in ten minutes flat! It helped that I bench synchronized them before the install and they were close, I only touched two adjusters and presto!

Remove all that air-sucker government imposed :bs: its way easier to work on your Cheers

 

Sir, it's happenin'. Got dem blankoff plates headin in here next week. Since I rashed her plastic it's a must that i get her underparts cleaned up. I'm going to retro streetfighter her out. i know it's becoming cliche but I have some good muses...

 

I like the orange one^.

 

Noob Question: What effect does shimming the needles have on the carbs?

 

Mid Range, thats it. Our carbs have washers when you take them apart, you could add a .02 washer in addition. I really did'nt notice a difference, my shimmed bike runs up the rev counter faster than the non-shimmed one does. Comparing apples and