• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

VM26SS Carbs

  • Thread starter Thread starter mike1414
  • Start date Start date
I'll pull the filter and look at the flow tomorrow. Hopefully it is something as simple as that! That would make my day. I've made some adjustments with the air screw to get it running, and it seems like it should be something simple to get it the rest of the way, so it makes sense that flow is a simple way to start.
 
mike1414 said:
What do these fuel screws do exactly?
Click to expand...

The screws regulate fuel in the pilot circuit. It appears you have carbs of a different colour and don't need them! There's always something new to learn! Pretty odd.
As per Greg, check the petcock and filter for blockage and rust in the tank.
 
Checked the flow today; "prime" the flow is great, "reserve" it dribbles out, and "on" nothing comes out, all of which I believe are pretty par for the course, right? The tank seems to be pretty good, there is no significant rust in there. So it looks like we're at least ruling out options now. It still seems to be a fuel related problem to me, though I don't know where exactly the problem could lie now. One finding that I forgot to mention could be significant, I don't know - though I have cleaned and rebuilt the carbs, when I open up the bowls, there is little-to-no gas in them. There are no leaks that I can identify, so that confuses me a bit. Thoughts?
 
mike1414 said:
Checked the flow today; "prime" the flow is great, "reserve" it dribbles out, and "on" nothing comes out, all of which I believe are pretty par for the course, right? The tank seems to be pretty good, there is no significant rust in there. So it looks like we're at least ruling out options now. It still seems to be a fuel related problem to me, though I don't know where exactly the problem could lie now. One finding that I forgot to mention could be significant, I don't know - though I have cleaned and rebuilt the carbs, when I open up the bowls, there is little-to-no gas in them. There are no leaks that I can identify, so that confuses me a bit. Thoughts?
Click to expand...

Recheck the float height - 24 mm. While you're in there, what size pilot & main jets do you have?
 
The float heights seem to be on track. I actually already bought new pilot jets/mains --> pilots are 17.5 and my mains are 117.5, up from the factory jetting. It was running previously with factory jetting, I just recently upgraded them (the PO put 4-1 V&H exhaust and pods)
 
mike1414 said:
The float heights seem to be on track. I actually already bought new pilot jets/mains --> pilots are 17.5 and my mains are 117.5, up from the factory jetting. It was running previously with factory jetting, I just recently upgraded them (the PO put 4-1 V&H exhaust and pods)
Click to expand...

I found 17.5 pilot a bit rich and went back to 15, but who knows what's happening with your pilot circuit since you don't have any and don't appear to need pilot screws. I wonder if the holes were blocked off and your cleaning them opened them back up?

Low fuel level in the bowls is down to greater evaporation because you have pods.

I hate to say it....but you may have to dip the carbs again to get this sorted. 24 hours for each carb.
 
I guess it would absolutely be worth it to trial/error my 15 pilots and/or 107.5 mains in different combinations. But MAN! Dipping again sounds like a nightmare; although I already haven't been able to ride it for 2 months, whats another week or two I guess, right? I'll do a little experimenting and then see where that takes me, then dip again as needed. Makes sense with the fuel/bowls though, I didn't think of that.
 
I'd still be looking at the tap. Check it functions in the on position by sucking gently on the vacuum line - running the fuel into a container.
I'd also let it run in the prime position for maybe a minute. If for example you've got a blocked tank vent it won't show up immediately but only after pressures have dropped in the tank.
The little to none fuel in the bowls is strange...
 
So I sucked on the vacuum and gas flowed well from the "on" position. I changed my pilots to 15, and after trial and error with the air screw, seemed to find a range that somewhat works. As I was experimenting with the outs and ins of my air screw, I heard what sounded like an open vacuum port, and further investigation took me to the picture below which is a vacuum port coming off of the block between carbs 1-2. I plugged it up with my finger, and the bike actually seemed to run quite well. What exactly is this vacuum port? Typically I have the vacuum from my tank connected between carbs 3-4, so I'm not sure what this one is. Thoughts?






I know that it's very blurry, but you can see the lost coming from the top left middle and the opening in the center. When I took my finger off, it sputtered and then stopped, throttle response was gone. When I plugged it up, it all came back
 
That pipe is in a weird spot! Where does it lead? The vacuum to the petcock comes off carb 3, not the vent between 3 & 4 - the vents on carb 2 & 4 should run over your pods into open air. Carb 1 has no vent. Is this how you're set up up or are there other strange things on your carbs?
 
Last edited:
The pipe-type thing, which has some suction to it, comes off of the bottom of the part of the block that connects to the intake boot of carb number two. It points downward at about 7 o'clock towards carb 1. The PO had the vacuum line connected to the vent of carb 4, so I will switch it to carb 3. But it still begs to question what exactly is this thing coming off of the bottom of the block/carb 2?

I tried to start it up today (with the vacuum from the petcock connected to the vent between carbs 3/4) with the pipe off of the bottom plugged, and it didn't want to seem to stay running. It started with choke and, once it heated up, revved up to 3k with popping and smoke. Seemed to run a bit better yesterday, but maybe I just have to adjust my air screws a bit better.
 
Connect up the petcock vacuum to carb 3 and things are going to start getting better. That pipe thingy looks like it's the connected to vacuum sync port and must be plugged, there should be a screw in there not a hose. You better check the others as each intake has one. Your bike will never run right with it sucking air in freely.
 
Last edited:
P1000425-w_zpsj14bxwhj.jpg
[/URL][/IMG]

This is the vacuum sync port with the screw plug.
 
For what it's worth that pipe is in the correct position for the factory vacuum takeoff for VM26's without idle mixture screws.
When the factory deleted the pipe from #2 carb boot they put the vacuum takeoff on the LHS of #2 carb.
Given you've got early type carbs, I suspect there is actually no vacuum takeoff on the carb bodies and you're hooking a hose up to the carb float chamber vents.
I'd try it with the petcock vacuum line going to the pipe under the inlet port - and check when it's running if there's a vacuum at any of the carb breather pipes.
 
Well put, fellows. Well put. Unfortunately I fly out of town for the weekend, so I'll be anxiously awaiting getting back to working on it next week. I'll be back with an update once I'm back to town, and I'll give each suggestion a try and see what works best. Can't wait!
 
Alright guys, so I got out to work a bit. I changed over to the vacuum port between cabs 2/3 and it made a seemingly significant difference. With the air screws 1 3/4 turns out, 15 pilots and 117.5 mains, it ran surprisingly well. Response was good, but slight popping and smells rich. I'm sure with a vacuum sync, though, I can fix that. A weird new occurrence, don't know what the issue is. I went to take it for a ride, clutch pulled all the way in and down shifted from neutral to first, it bucked forward and cut off. Never done that before, not necessarily because of me having been working on my carbs. What could be this issue, and I assume that a good vacuum sync will solve the rest, yeah?
 
So today I went on another ride to check the surf, short ride, just to see how she'd do. It's definitely still running rich. You can smell the gas burning, the throttle is shoddy at first turn, there is slight popping, it's idling around 2000rpm, and my plugs are all black. The reason that I initially started working on the bike (outside of it eventually having stopped running) was because my V&H 4-1 began bluing at the manifolds. So - my bike has this exhaust set-up and K&N pods. The PO had it factory jetted. I started tweaking with the air screws, no go still. I went up to 117.5 and 17.5 - gas was leaking out of my overflow tubing. I went back to 15 pilots, and it's better, but I still have slight leakage out of the 4th overflow tubing, and the drain plug on 1 is wet (I need new drain plugs, but still). My carbs are only bench synced, not vacuum synced, but is this all it is gonna take (vacuum syncing them) or does it sound like I still need more trial and error with jetting? Can I just wire brush my plugs or should I start fresh? Anyone?
 
You must log in or register to reply here.
Back
Top