stuck slide?

[rocker2229]

Okay, I just picked up a new to me 1994 Vmax with what I am guessing is a stuck float. The bike is stock, except for Supertrapp slipons and has only 4450 original miles. The oil and plugs were just changed, and the old plugs were a nice light tan color suggesting decent jetting.

Once the key is turned on and the v-boost and fuel pump spring to life, it dumps fuel out of the back left carb (if you were sitting on the bike) overflow tube near the airbox. When I pulled the airbox off to have a look, that carb slide if stuck open, meaning it's not visible like it is in the other three carbs. The other slides are about 3/4 to 7/8 closed. Any ideas what would cause the slide to hang up like that? Since the bike was sitting for quite a while before I bought it, I poured some seafoam in the carbs directly and some in the tank hoping that it is simply gummed up with crappy sticky ancient gas.

The bike will fire and run with the choke on but pukes gas on the floor and the right pipe smokes likes it's rich, which given the gas everywhere I know it is.

I tried to tap a few times on the side of the carb to free the sticking float without success, but I will give the seafoam time to work. Other suggestions and in particular about the slide?

David

 

[naughtyG]

You really need to give those carbs a good cleanup. You can try the 'shotgun' method (search for it here the instructions are simple) but if it's been sitting for quite a while there's no better way to put things right than to take the carbs off and clean them properly. I made a full photo thread on how to do this, I think it's in the 'how to' section.

Also take a good look inside the fuel tank with a bright light, if you see any rust it will have to come out (also easy) and get treated/coated or you'll never see the end of your troubles.

 

[rocker2229]

thanks for the suggetsions NaughtyG. I checked the tank and it actually looks quite good. Nice and clean with minimal rust. Most of it is clean metal and I can clearly make out the small screen at the bottom (just north of the reserve sensor) which isn't obstructed. I will pull it and coat it at some point just to be safe, but rust flakes don't seem to be a factor at the present time. The bike overall is quite clean and lied under a tarp in a garage.

Any idea what could cause the slide from the 1 carb to stay stuck all the way back like that?

David

 

[sdt354]

I'd pull that carb cover and inspect the diaphram good. If it's bad I'd check all diaphrams.
Steve-o

 

[[email protected]]

Does the slide close when the bike is off, or is it open all the time? Can you push it open easily with your finger and does it spring right back?

If no to any of these then you need to clean up the slide and bore in the carb that it rides in. Remove faux tank, side scoop, then you have access to the carb cover. Remove the screws from teh carb cover, be careful and watch for a smalll oring to fall. It usuallyy stick in place though. Pull the slide out, clean the slide, clean the needle, and clean the bore of the carb and make sure the jet that receives the needle is not gummed up.

Probably just has some varnish in there fro sitting.

Tearing the whole rack down and giving it a good cleaning and float adjustment is the best way to go IMO. Renew any deteriorated old rubber with new OEM stuff. Its not too costly on this bike, is relatively easy compared to many others.

 

[rocker2229]

Mike,
the faux tank and scoop are off. The slide doesn't spring back. If I take off the side cover to access the slide, is the gasket behind the cover reuseable? (I'm lazy and cheap!:biglaugh I am hoping the diaphram isn't jacked up and that it's just some varnish making the slide stick. I will pull the cover off on Wednesday and see what it looks like inside.

I am trying to avoid pulling the carbs off. Without pulling the carb and then the float bowl, any suggestions on how to access the float easily to get it unstuck?

anyone?

thanks in advance,
David

 

[MaxMidnight]

I just picked up a new to me 1994 Vmax with what I am guessing is a stuck float.
Once the key is turned on and the v-boost and fuel pump spring to life, it dumps fuel out of the back left carb

...that carb slide if stuck open, meaning it's not visible like it is in the other three carbs.

The bike will fire and run with the choke on but pukes gas on the floor
I tried to tap a few times on the side of the carb to free the sticking float without success

There seems to be two issues here
i) A stuck float
As you have tried the usual 'light tap' freeing off method without success then you will need to remove the float bowl to find out what the problem is.
It is not uncommon for beavers to take up residence over winter or a small particle of dirt to get stuck in the needle seating (one of those suggestions is made up - can you spot which one it is readers?)

ii) The slide isn't returning.
You will need to remove the cover and see what is going on - has the previous owner removed or forgotten to put the return spring in?; more dirt??
We can all offer suggestions but the only way to be sure is to take the lid off.
Note that there is an anti tamper screw that can be removed with some good fitting mole wrenches.
If memory serves me well it is the diaphragm rubber that forms the seal so no worries about having to replace a gasket.

 

[naughtyG]

Yes take the cover off and carefully unpeel the diaphragm, there is no seal there.

Then see if you can pull the slide out gently. If it won't budge it's defo gummed up. Use WD40 or carb cleaner spray or both and let it soak in a bit then try again - eventually you should be able to pull it out (you can also push from inside to help).
Once you got it out give it a good clean, soak in carb cleaner if needed (BUT only the slide part, NOT the diaphragm as carb cleaner will eat rubber).
It should slide in and out easily once lubed with a little WD40. If it really won't you can try giving the offending part a very gentle rub with 1000 or 2000 wet sandpaper, but hopefully you won't need to.

All 4 diaphragms must be in good shape (no holes or tears) or your Max won't run nice, and yes these mfkrs are expensive..

 

[Fitz666]

Couldnt agree more on the carb rubbers, I had the very same issue and it was a torn rubber, about ?45 here ($71).

 

[sdt354]

If the slide is stuck from crud, the carbs need a tear down, complete. That's not a super tight fit between the slide and bore. Like Steve L said, there is one security screw on each carb, unless they have been replaced. I use allen screws in place of those. I bought a cheap torx socket set with a hole for the security screw. They can be hard to find. Other methods can get the screw out also.
Steve-o

 

[sdt354]

http://vmax.lvlhead.com/tips/shotgun.htm This should help you out. We've got some great threads here to research too. I replaced all 4 Diaphrams 2 years ago with after market brand
rubbers. The cost was about $100 for all 4. They are not as soft as the OEM, which worried me, but work well.
Steve-o

 

[[email protected]]

I have found that the needle and jet can get gummed up and stick together from varnish deposits. That stuff can get pretty hard. I found that marine clean does a great job of removing deposits from anything metal. Not sure how it would react to plastics and I'm not going to be the guinea pig.

It could be the slide itself too. Either way, the diaphragm cover needs removed. As noted, no gasket needed there. Just watch for the o-ring.

No way to access the floats really without removing the rack. The rack is dead easy to remove. Remove faux tank and both scoops. Unplug fuel pump, remove hose, lift coolant tank outta the way, disconnect throttle cables in the junction block, loosen 4 screws on the air box boots and remove. Loosen 4 screws on the boots under the carbs and yank up. Done. I like to crack the diaphragm covers loose before pulling the carbs and drain them first. Some guys drain all the carbs at once through the overflow hoses. Either way. Just don't drain them into a styrofoam cup. :biglaugh:

 

[rocker2229]

wow...guy.s..I am blown away by all the help and suggestions on this forum in just a few days. I appreciate the help so far. I am used to single carb bikes (like my KX250) or my fuel-injected Triumph that can be adjusted with a laptop. I wont get a chance to do much until this weekend and will leave an update here of what I find.

Quick question about pulling all 4 carbs. If I pull the carb rack, won't the carbs need to be sync'd?

thanks again,
David

 

[KosRider]

Yes, if you pull the carb rack, you'll need to / should sync them once reinstalled.

 

[naughtyG]

Quick question about pulling all 4 carbs. If I pull the carb rack, won't the carbs need to be sync'd?
David

Yes. A sync tool runs around $100. If you have another Max owner anywhere near you, they should have one and be willing to lend it to you.

If not, you can actually make (!) one for around $10. Do a search here for full instructions - all it takes is a plank, some clear tubing, ATF fluid and a few fittings.

 

[rocker2229]

I did a search and couldn't find the plans for building my own, so I think this is just the excuse I need to order a Morgan Carbtune Pro which will also work with the throttle bodies on my Triumph Sprint. At least that's my story and I am sticking to it. I hope to pull the carbs this weekend and work some magic, but the carb sync will have to wait another week or 2 until the Carbtune gets here from across the pond.