Running Rich ? VS1400

[Herb]

chapter 9 of the service manual has a bunch of cable and hose routing diagrams. Maybe those will help you.

[Lechy]

this also works well when fitting the boots:

[Springer Fla]

It is probably too late now but I’d suggest loosening or removing the Balance Screw (for syncing the two carbs) before you install the rear carb. Be especially careful and not lose the washer or screw. #39 ?? as shown in the diagram. My manual has a different # and no washer is shown. The sync port is tightly behind the fuel shut off and lines and the sync tube connects tight against the bike’s frame.

I agree with Jinx and quoting him… “I have been chipping away at getting those carbs back on for the last few days after fighting the elbow for the air box on the rear carb and the obscenely cramped space where the carbs are located. I am surprised I haven't seen the carbs in my nightmares yet to be honest.”

Like Jinx, I’ve been working on my carb issues since mid autumn of 2023. I’ve R&R-ed these carbs over a hundred times (both S50 & S83) and I actually hate these bikes for being designed so tight. Also, wires and hoses over time get hard and brittle and many times I can’t find and extra 1/8” of slack.

Anyone – correct me if I’m wrong; My Clymer S83 manual on pg 235, under Carburetor Separation and the first sentence says, ”The carburetors can be removed, disassembled, cleaned, assembled and reinstalled w/o disconnecting any of the cables from either carburetor." I’ve always found the rear throttle cable to be too short and at a no fit angle and I have to disconnect it and run it under the welded frame where the front of the seat and gas tank mounts. I have better results if I run the choke cable under that small frame as well. This takes an incredible amount of time and the cable adjustments aren’t easy at all. For this and other reasons, I haven’t been around to post.

Daytona, Fl is just up the road. The Big 500 race is rained out today and Bike Week is in two weeks. I hope I can get my S83 rolling and then I can post more often. It’s been a long winter.

[Springer Fla]

Currently, I have a flooding problem on the rear carb, where fuel instantly runs out. This is probably due to an improper float level or a bad Float Needle or the FN valve o-ring. It just occurred to me last night… Why bother hooking up all of the cables when float adjustments have to be made.?

First connect the choke (if the engine is to be started) and the lower fuel line, which goes to the fuel pump. Then Amoral the carb and insert it into the rubber intake. Next connect a 18” or 2’ piece of clear tubing to the top fuel pipe, which usually goes to the front carb. I use a “Fuel Bear” (older honey or ketchup bottle with a nipple) to fill the clear tube with gas. The bike can briefly run with a full bowl and the fuel in the 18” of clear hose and if you connect another fuel line to the front carb.

*My rear carb problem is; that the previous owner did not support the post – with a small socket, where the float pin goes thru. Sometimes the pins get tight and stick. They broke the cast zinc / alum post and repaired it. It lasted for a while and then it fell apart, after I had bought the bike. They also twisted the float to match their repair. I’ve got to hand it to them; they did a good job adjusting the float, since it ran good when I bought the bike.

*My repair was to drill a tiny hole into both centers of the broken post. Then I can insert a piece of SS welding rod or a small nail. Then glued it with JB weld. Then I covered the JB repair with (Red Kote) gas tank sealer. Now, I’m trying to un-F the twisted float. I found the tang on a good OEM float to be perfectly flush to the float body, by using a small straight edge > opposite the soldered side.

For decades of carburetor work, I needed the following carved in stone because I tend to forget and for some reason nobody ever prints it or it is poorly shown or described...

The TANG should be bent TOWARD the valve for LESS fuel (lean) and AWAY for more fuel (rich).

My goal is to find the proper 14.7:1 air / fuel mixture in the bowl and venturi so the engine can get a sniff of gas for cold starting. Actually, I’m looking for 13:1 for a rich condition.

I haven't been near the bike since my last 2/18 post. This process is slow going on a "junk" bike and it isn't on my C50 daily rider. More later.

[Jinx]

Thanks for all the advice everyone.
OK, so another update hooked fuel bottle up and started the bike today seems to be running better although obviously the carb balancing is still out.
Two questions at this point firstly I have the low speed pretty well sorted with the sync cable but when I open the throttle to do the high speed which from what I understand is adjusted with the throttle cables the needles take off in two completely different directions and the bike sounds unhappy so I'm not too sure what I'm doing wrong as adjusting the cables really isn't doing much.
Secondly where should I have the mixture screw positioned, again my bike is one size up jet wise due to exhaust should the still be the turned to the setting listed in the book or out further ?

Thanks again for the help I know this is probably getting tedious but carbs are not nor will they probably ever be my friend

[Herb]

Thanks for all the advice everyone.
OK, so another update hooked fuel bottle up and started the bike today seems to be running better although obviously the carb balancing is still out.
Two questions at this point firstly I have the low speed pretty well sorted with the sync cable but when I open the throttle to do the high speed which from what I understand is adjusted with the throttle cables the needles take off in two completely different directions and the bike sounds unhappy so I'm not too sure what I'm doing wrong as adjusting the cables really isn't doing much.
Secondly where should I have the mixture screw positioned, again my bike is one size up jet wise due to exhaust should the still be the turned to the setting listed in the book or out further ?

Thanks again for the help I know this is probably getting tedious but carbs are not nor will they probably ever be my friend

Carbs are a mix of experience and FM (fuckin magic).

Mixture screw, between 1.25 to 1.5 sometimes as much as 2 turns out and not always the same on both sides. Turn them in until the engine starts to miss, turn them out until it blubbers and center the 2 settings.

Cable adjustment, keep in mind that shortening the cable will make the other cylinder vacuum rise and lower the vacuum on the adjusting cylinder, lengthing it will lower the other cylinder and raise the vacuum on the adjusting cylinder.

The cylinder that is pulling the engine the most (doing the most work) has the lowest vacuum and the one doing the least amount of work will have the highest.

it takes a lot of trial and error to work out the kinks in the system. However, understanding the relationship of the amount of work being done will help you to figure it out.

[Springer Fla]

Thanks Herb - for this great info. While not carved in stone, I'm certainly going to copy this and keep it in my my Service Manual.

Carbs are a mix of experience and FM (fuckin magic).

Mixture screw, between 1.25 to 1.5 sometimes as much as 2 turns out and not always the same on both sides. Turn them in until the engine starts to miss, turn them out until it blubbers and center the 2 settings.

Cable adjustment, keep in mind that shortening the cable will make the other cylinder vacuum rise and lower the vacuum on the adjusting cylinder, lengthening it will lower the other cylinder and raise the vacuum on the adjusting cylinder.

The cylinder that is pulling the engine the most (doing the most work) has the lowest vacuum and the one doing the least amount of work will have the highest.

it takes a lot of trial and error to work out the kinks in the system. However, understanding the relationship of the amount of work being done will help you to figure it out.

[Jinx]

Hey all, thanks again for the great info I have I believe however reached the point of potential surrender I may or may not be sitting here with an ice pack on my head
So cut a long story short put clean plugs in and fired the bike up today with a fan in front of it. Ran ok initially low speed balance still appears to be ok, however it didn't take a huge amount of time to go downhill from there before I could get a chance to start trying to adjust the throttle cables it started popping a backfiring and developed an idle so low it kept shutting off regardless of idle speed input pulled the plugs they still look reasonably clean but it's more or less now refusing to stay running at all.
I think realistically to put it simply as much useful advice as I've got I simply do not know what I'm doing with these carbs. I really don't want to put the bike in storage as I've put a lot of time and money into it and it is now very tidy but I'm simply not prepared to put anymore time and money into it if it won't return the favor. Any last bits of advice would be great but I think it might be going into my brothers garage for indefinite storage next to his also dead 80's Japanese bike which I believe also has carb issues too.

[navigator]

Initially put a little extra slack in the throttle at the grip. If there is no slack before the butterflies start to open, you will never get it.
2. Adjust the front throttle cable at the carb so that both butterflies start to move at exactly the same time. You can stand on the right side of the bike and operate the grip with your right hand...reach over with your left hand and touch the front carb linkage...you can feel it start to move...observe the rear carb linkage, they should start to move at the same time.
Now you have the sync statically close. You can start the sync process now. Do the idle sync first, then move to the throttle sync...holding the rpms about 2000 with the grip.
Small adjustments make a large difference, so much so that simply tightening the locknut without holding the barrel will change the sync.

Patience.

[Springer Fla]

I've got to laugh at Jinx's use of emoji s. > Same here. For years, I fought with my VS750 because I didn't have the $ or wouldn't pay the $40+ for float needles and seats X 2 cyl. The VS1400 is more of a PITA because it has the extra Decompression and Boost Sensor lines - right in the way, for the rear carb. IMO; these bikes are made to damned tight.

Navigator is right about a wee bit of slack.

Initially put a little extra slack in the throttle at the grip. If there is no slack before the butterflies start to open, you will never get it.

Usually, I just turn the throttle and "feel" the tension and visually watch where the cable starts to lift the throttle. At this point, you have to understand what you are doing. With the carb off the bike and visually, you will see some VERY small drillings near the butterfly and the butterfly will completely cover one drilling (when choked) or a portion of it. For a portion of such a small hole being covered, that is your 14.7:1 air / fuel mixture and the more the TINY drilling is uncovered - the faster the idle. (I've never had any luck with the carb sync screw. I use the vacuum gauges and just set each carb.) If you can, go to a mtc junk yard (or repair shop) and look at the butterflies and drillings on a bank of 4 carbs and you will get a better idea of how they sync.

Try your Library or check AMZN or Ebay for Haynes Fuel Systems Techbook by John Robinson #3514
I also have Haynes Electrical Techbook by Tony Tranter #3471 3rd ed.
Libraries also have boxes of real puzzles if you decide to give up on carburetors.

I still have a flooding problem on the rear carb only, which is OEM float tang and the carb came off a running bike that I parked last Sept 2023. Today's gas is crap. It already started to form a green powder in the bowl & other components. JINX - if you store the bike, absolutely drain the carbs or better yet, clean and dry. Since I will not touch this tang, I changed the Float Needle and seat with O-ring, from a China knock off kit from ebay > but at least you get the whole kit (I needed the bowl gasket) instead of being outrageously nickle and dimed by Suzuki. For now, I'm back to the carb where I repaired the float post with JB Weld and at least it is not flooding. I only have time to occasionally tinker with it. I'd rather be building my Honda Chopper and I have other priorities. Also, Daytona Bike Week started yesterday.

[hillsy v2]

Unfortunately that's what happens when you build a bike primarily for the way it looks. You have to hide a lot of stuff and have complicated linkage systems to achieve the design. Some people say the VS is the best looking bike ever made in that regard. Admittedly most of them are on this forum and are possibly biased

[Jinx]

I think I pretty much agree with the fact that it's been designed around the way it looks. I ended up getting the balance as close as I could did an oil change and put new spark plugs in. Fired it up this afternoon and it's gone right back to running terrible again back to dying when I crack the throttle if I richen up the idle screws it'll run OK for a while then start going absolutely ape s**t again then if I try and screw the mixture screws in it'll start back firing and spluttering. Even if I go in between it'll run OK for a small amount of time then go nuts again. I think at this point I will drain the fuel and remove the battery and store it. The reality is the obscene amount of money I have put into this bike and time as well as I said is simply not being returned.
I think simply it's just far to complicated I'm sure if it worked properly it'd be great but I think without someone who knows what they are doing that's never going to happen.

Appreciate all the help I have learned a lot working on this bike and from everyone here and I feel bad putting it in storage but that's what's happening.

[azazelakira]

Unfortunately that's what happens when you build a bike primarily for the way it looks. You have to hide a lot of stuff and have complicated linkage systems to achieve the design. Some people say the VS is the best looking bike ever made in that regard. Admittedly most of them are on this forum and are possibly biased

No the bike I like for the looks the most is the Trumph 3 cylinder, I forgot the name. The second one is the Honda Interstate (vt 1300 I think). I love the Intruder because I got in love how is small but has a big punch, bad thing is all is compacted under the seat and fuel tank. I had to send mine to a shop because I don't have the tine to mess with it. Should be ready next mont. Also nobody in my town wanted to work on it but the oldest shop in town.

[Springer Fla]

Yo Jinx, I wrote the following after Hillsy's 3/02 post but I never got around to posting. I figured that you parked the bike as I have done with mine. These bikes are mfg to damned tight to work on and are therefore too time consuming for me. My s50 (1990 VS750) was a bit easier.

The best advise for syncing carbs is what Herb and Navigator just posted here. This board offers real life experience that you won’t find in tech books. For example; If something critical has to be removed and replaced exactly as it was, such as carburetors, then I count and measure the threads and write it down before wrenching on it. I also use machinist’s layout dye or welder’s permanent marking pens to index O’clock positions. This is sort of like spray painting and then finding the bare spot. Older cables rust that way. Write down every move on air screws. I also, buy cheap screwdrivers at flea mkts to grind down just for carburetors. As I remove parts, I keep them all in dedicated trays.

Over the weekend, I searched and found (only) one of my old notes. Here is the OEM cable settings for a 1999 VS 1400 and if I recall from 10 – 15 yrs ago, they are the same for the S50. The cable ends are the same – just different lengths.

First thing… I refer to the threads at the end of the cable as “Stick Out” and between the cable barrel and the lock nut as “Between the nuts.” I use a 6” machinist’s pocket ruler x ½”wide.

Rear carb = 1/8 to 3/16” bottom stick out or 3 threads showing. Between the nuts = 6/32 or 6-7 threads showing. Be careful not to damage or fray the end of this cable. You can bank on this measurement.

The idle adjuster and the cable adjuster under the gas tank have always been junk to me. It never worked on my new S50. I simply sync the two carbs by adjusting the throttle cables. Of course there is no idle screw adjustment that way. The adjuster under the tank “stick out” is exactly the ½” width of the ruler and at 12 threads showing. (Bank this ½” measurement)

The front carb = 5/16” between the nuts or 8 threads and 10/32 (3/8) stickout at 8 thrds. My notes are a little shaky on this one but it mounts around half way on stickout and BTN.

The tank is off the bike that I’m currently working on and these notes match that setup. + or – a thread.

After all my years… I came across this last night in a Clymer VS1400 Suzuki 87-07 Manual and adjacent to and before Chapter ONE. Pg X
Throttle Cable Ends
(carburetor synchronization) 18.5mm (.73in)
I have no idea what this is and I don’t see anything more in the manual about it. Sometimes, these manuals can be sadly lacking. I hope this helps.

[Springer Fla]

Fired it up this afternoon and it's gone right back to running terrible again back to dying when I crack the throttle if I richen up the idle screws it'll run OK for a while then start going absolutely ape s**t again then if I try and screw the mixture screws in it'll start back firing and spluttering. Even if I go in between it'll run OK for a small amount of time then go nuts again. I think at this point I will drain the fuel and remove the battery and store it.

It seems to me that you may be over doing it with the air screws. Generally, most motors will run when set at 1.5 turns. I use a set of vacuum gauges and sync the two carbs with throttle cable adjustments and ignore the idle adjusting screw. After sync, then you can tune in the air screw “roll,” in 1/8, 3/16, or ¼ turn increments and generally not past 2 turns. Dig deep into past pages on this topic and also on the S50 as they are pretty much the same bike as the S83. As in my last post, count the threads, measure the length and start a notebook.

IE and staying on topic > I’ll take a new bike and the first thing I do is to remove all exhaust bolts. I oil and / or Never Seize them and run them in and out a few times and then torque them down. As most mechanics know… these extremely heated nuts and bolts tend to freeze up, over time – resulting in snapped bolts or threads getting so tight that they actually weld themselves together – so to speak. Just the act of running the bolts in and out a few times makes future repairs easier.

Now, look at the 3 tiny drillings near the butterfly and think of the tiny needle of the air screw and the possible damage to the zinc alloy casting or the little o-ring, every time that you seat the air screw. While there is an o-ring in there, and in my example above, the more times that you “loosen” the threads could cause an air leak.

Also, the air screw has a whopping 1/32 shoulder with a wide slot and soft metal that can easily burr which could destroy the very fine threads of the zinc casting. Air screws are dangerous territory and shouldn’t be tampered with any more than necessary. Make your adjustments with the cables first. I’ll grind down screwdrivers just for carburetor air screws and jets.

For the “regular” guys on here… I’m putting my S83 in storage. I’m here but not posting. I’m building a Honda chopper as well as re-modeling and re-roofing my home (by myself), so I’ll be a gone while.

While using a carb that came off a running bike, I’ve come to the conclusion that either the fuel pump is weak or the rear manifold rubber has a hole in it from R&R the carb too many times. It turns out that it wasn’t exactly a bad carb but also a weak spark. From reading past pages, I found that re-doing the ends of the spark plug cable fixed the spark issue. The aluminum resistors had unbelievable white corrosion. The previous owner abused this bike and let it sit out in the weather. Now, that is fixed.