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2006 Vulcan 750
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Discussion Starter · #1 ·
Hello,
My recently bought Vulcan 750 has a few disconnected hoses, can you help me figure out where they all go?

FYI the bike has the ear shave mod, where the airbox has been removed and replaced with K&N filters.
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Picture #1: a big brown hose that's right under the fuel tank
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Picture #2: 3 hoses under the fuel tank, I know those connect to the fuel tank directly. but which one goes where?

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Picture #3: A hose on the top of the coolant reservoir, manual says it's the overflow hose. does that mean it doesn't go anywhere?
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Picture #4: Small hose right behind the engine on the front side of the bike. I have no idea where this goes.

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The small hose on the front of the bike is/was probably the "drain" for condensation from the bottom of the air box that has been removed. The large hose with the grommet went into that box also, it then went back toward the charcoal canister. I seem to remember it going to a diverter valve that was vacuum operated and to the charcoal canister. I cannot tell if your charcoal canister has been removed or not but it looks almost like you have more room at the back of the engine than you would if it was still in place. It was part of the "smog" stuff that is not used after the ear shave. I would hope the bike has been marbled since the hoses are still in place and run from each side of the engine from each cylinder to the back of the motor. Those hoses can be removed and either add "coasters" or cap the reed valves off. If the charcoal canister is still in place there will be several vacuum lines down there that can be deleted, consolidated or just removed completely. After the air box is removed the smog system cannot really be made to work as well as it was designed to and the bike will run better if there are no open and unused ports.

The coolant bottle has one overflow line that runs from the thermostat housing all the way under the gas tank and down to the bottle. The bottle then has a line that loops up and over, then down toward the ground just in front of the rear wheel. There should be a vent hose from the carb assembly and up toward the bottom of the gas tank. Some guys stuff it into the frame under the tank. Others will attach it to the bottom of the tank for the "dead" air it needs. It used to go into the back of one of the ears. Then you will have a small hose going to the petcock that supplies vacuum to it. The other two larger hoses will be the fuel supply hoses between the carbs and the fuel tank. You will probably be better off if you just look for what you need rather than trying to hook up what is there if you are not who did the earshave and removed any parts. It can get complicated to try and reconnect everything if some of the parts have been made unnecessary because of modifications. There is probably 2 or 3 feet of vacuun tubing running between the charcoal canister, the fuel tank and the carburetors. You can safely remove most of it and make the system simpler and more reliable. Good luck
 
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#1 could be the crankcase vent but it's should be at the front of the engine. So it could be leftover from the air box and the suction valve under the seat. It hasn't been coastered so those reed valve hoses are running to nowhere, those need removed and then do coasters or marbles.

#2 should be two fuel inlet hoses that run from elbow fittings on each carb.

One carb vent originally connected to a tee with one vent hose coming from each carb. The carb vents have a fitting sticking straight up out of each carb.

So fuel connects onto elbows and vents on the straight up fittings.

The vent needs to be in dead air space, one the frame tube under the tank or the plastic cover on the fuel gauge sender on the bottom of the tank.

#3 should be one hose from beside the radiator cap to the coolant tank.

#4 is probably the condensation drain originally from the bottom front of the air box and dangled toward the ground. Remove the hose, it's no longer needed.
 

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Hey Spockster, great minds and all that. I ran my crankcase vent on the other side of my bike so I couldn't tell if there was one on this bike or not. The drain on my bike's air box was on the opposite side from what is shown also. Originally, I was wondering if the bike was running at all when you got it or not. Plus those filters seem a little white to me but maybe it is just me. The K&N filters I have are very shiny chrome and red, not pinkish red - red. . Make sure they are oiled properly, even if you need to clean them and re-oil them. It is possible the filters are oiled with other than the K&N oil but you do not want to run them with no oil. These bikes need filters. Good luck.
 

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Discussion Starter · #8 · (Edited)
Lucky me, 2 great minds replying at the same time. I can't thank you enough, that was a lot of info!
I'll start from the top with everything:
2006 Vulcan750. Only 794 miles. got it from a 20 year old kid who had the bright idea to mod it BEFORE getting it to work. He got it from another guy and it wasn't working.

More pics can be found in this post: Need help reading the gauge

It's my first bike, so if you have to use dummy terms I wouldn't mind.

Changed Oil, Coolant, Carb is spotless and so are the Jets.

I live in California, so I'm assuming this is a CA bike.

I think those are just some Chinese aftermarket white filters, not K&N.

#1 Large Brown hose with Grommet has been removed. it was attached with a silver connection. Pic attached. I have no idea what a charcol canister looks like.
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#2 I'll deal with those 3 black hoses when it comes time to install the tank back

#3 Just put this hose over the reservoir where it can drain into the ground

#4 Condensation drain it is! it was connected to nothing and just draining to the ground. removed.

now a few questions from a noobie:

1. what do you mean by "Marbles/Coasters"?
2. what's a crankcase vent? I attached a pic of a blue-looking filter. is that it?
3. Filters are brand new. the guy never bothered to install them. what do you mean to oil them? I thought those were air filters? Pic also attached.

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I got my pics!

The silver piece in #1 is the suction valve for the Reed valve system. It can go away if you are doing marbles or coasters, which are simply ways to block the Reed valve ports after removing all the hoses and hardware for the system. Just search those terms and there's plenty of info, should be some pinned threads too.

Those air filters have cotton gauze that get oiled to trap dirt. If they're k&n knockoffs they can cause problems if they block the venturi ports on the rear of the carbs. There's a sticky air filter oil in spray cans.

The blue part is a fuel filter which sometimes can cause fuel flow problems, make sure the fuel hoses run downhill to the elbow fittings on each carb.
 

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Marbling or coastering are two ways to cut off the reed valves, since you don’t have the air box installed it looks like coastering will be your best option. Which simply means you’re putting plates on the heads where the reed valve hoses run to. In other cases (like my bike) I didn’t remove the air box, so a standard marble is just the right size to plug the hose right at the connector.
 

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I am not sure what kind of petcock you have but I only see 1 filter and cannot tell if there is a Y split to the carbs after the filter or not. Maybe the other is on the fuel tank. The use of filters has been discussed often here. I guess it depends on the condition of your tank. I would be concerned as to how much fuel they flow at highway speeds. Around town they probably would be fine and if the flow freely they wouldn't hurt. Although most of my problems follow the actual gasoline going bad not dirt getting in the tank/carburetors.

If you don't have any marbles laying around I pulled mine out of old empty spray paint cans. They seen to usually contain a cheap green glass marble or a blue one. Years ago some used to have a steel ball in them that was smaller than a marble but no longer. My grandkids love taking a claw hammer to old paint cans to get the marbles out. With adult supervision of course. Good luck.
 

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Discussion Starter · #15 ·
I think I'll do coastering instead of marbling, just because I hate the look of those hoses. good thing we got a storm coming to California, gives me a week to work on the bike.
 

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The horsepower increase is not really why I think most will switch to a K&N filter and however much it does increase, it will not really be a lot. The bike is only rated at about 65 hp when new. so even if you switch and get an additional 10% increase you won't really notice it except through the "seat of the pants" dyno. You will get probably a better response and hopefully increase your miles per gallon. Since the only way to change the final gear ratio is by selecting a smaller or larger diameter rear tire the increase in hp doesn't translate into great performance gains. A lot of us like the looks better after the shave and it makes the bike easier to work on.

You would probably notice a improvement riding with a passenger though. I do not carry any one with me so I cannot really speak to that.

On my 1974 H2 I swapped out the stock filter, which was really restrictive, and went with individual filters like the K&N. I was able to swap out the sprockets and picked up an additional 10 miles an hour top speed easily (on the speedometer) and I was able to reach it much quicker. I grew up in the sticks out in northeastern Colorado and I had some wide open highways with very little traffic so I could test for improvements in the same manner and on the same stretch of road with no issues. Of course back then there was no GPS so unless I was clocked by the CHP on radar I could only really guess at the actual speed.

Swapping out the Vulcan's stock filters with K&N filters in the pods gave me about an extra 10+ miles on a tank of gas. However I still could not go from Sacramento to Reno without using more than a tank of gas. On the open highway I only get about 90 miles before I have to switch to reserve. I really only noticed the improvement around town if I was riding with someone else who rode in a more sedate manner. No matter how much the horsepower is increased your top speed is still determined by the engine rpm and gear ratio. I do not ever go over redline so even if I had a 100 horse engine my top speed will stay the same.
 

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Discussion Starter · #19 ·
The horsepower increase is not really why I think most will switch to a K&N filter and however much it does increase, it will not really be a lot. The bike is only rated at about 65 hp when new. so even if you switch and get an additional 10% increase you won't really notice it except through the "seat of the pants" dyno. You will get probably a better response and hopefully increase your miles per gallon. Since the only way to change the final gear ratio is by selecting a smaller or larger diameter rear tire the increase in hp doesn't translate into great performance gains. A lot of us like the looks better after the shave and it makes the bike easier to work on.

You would probably notice a improvement riding with a passenger though. I do not carry any one with me so I cannot really speak to that.

On my 1974 H2 I swapped out the stock filter, which was really restrictive, and went with individual filters like the K&N. I was able to swap out the sprockets and picked up an additional 10 miles an hour top speed easily (on the speedometer) and I was able to reach it much quicker. I grew up in the sticks out in northeastern Colorado and I had some wide open highways with very little traffic so I could test for improvements in the same manner and on the same stretch of road with no issues. Of course back then there was no GPS so unless I was clocked by the CHP on radar I could only really guess at the actual speed.

Swapping out the Vulcan's stock filters with K&N filters in the pods gave me about an extra 10+ miles on a tank of gas. However I still could not go from Sacramento to Reno without using more than a tank of gas. On the open highway I only get about 90 miles before I have to switch to reserve. I really only noticed the improvement around town if I was riding with someone else who rode in a more sedate manner. No matter how much the horsepower is increased your top speed is still determined by the engine rpm and gear ratio. I do not ever go over redline so even if I had a 100 horse engine my top speed will stay the same.
That's actually an interesting read. and hold on, are you in the Sacramento area Green1?
 

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Yes I do. I am in Citrus Heights close to Roseville. Moved down here from Cameron Park just over ten years ago. I've been here in California since the late 80's. Moved here because I got tired of snow. I love the sunshine.
 
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