Semi-abandoned Hammerhead 250

[KenMathisHD]

Can anybody provide some insight on how the hoses are routed for the carb on a hammerhead 250? Specifically the ones circled in these photos. One goes to a barb at the bottom of the carb bowl which I’m guessing is just to drain the bowl, but the other is sort of on the top left of the carb. It’s been in a state of semi-disassembly since before I picked it up, so I’m having to figure out/guess how some of this hooks together.

 

[Denny]

Bowl vent and bowl drain? Look on the inter web see if you can find a manual for it. That would be my best advise.

 

[KenMathisHD]

Bowl vent and bowl drain? Look on the inter web see if you can find a manual for it. That would be my best advise.

I found a manual for it, but it’s not clear on the hose routing. I went through a couple videos online though and I think you’re right, one guys says they’re both overflow/drain hoses. I also noticed that I’m missing the hose from the diaphragm on top of the carb to the front, which I suspect is a reason why fuel isn’t getting through to the chamber, need to find a new hose for that.

 

[Budget GoKart]

if its not fuel or vacuum dont worry about it

 

[Denny]

No, budget he has to worry about it. One may go from the crankcase vent to carb to remove excess vapors. I’m sure the one on the bottom is for the drain. 90%
One may be for a pulse fuel pump?

 

[Budget GoKart]

i ripped the hoses off my 250 and ran what was neccisary and it ran fine blocked any off that where not drain vacuum fuel also one is probably for a pulse pump

 

[Denny]

If the factory put it there it is necessary. By making statements like just rip it out you are showing your youth and inexperience. It is best to have someone repair it correctly than to just rig it.

 

[Budget GoKart]

im not saying rip everything out, im saying use as neccisary to run it then figure it out after its running properly what can be used. not everything on these buggies from the factory works i couldnt get mine to run in stock form because it had a bunch of hoses going places and most of them where clogged or dry rotted so i removed them and figured what i needed for it to run. i had it running really well and the fnr box blew out and torque converter granaded because the previous owners wrecked it so many times.

 

[madprofessor]

Knowing zero about Hammerhead, and based purely on mechanical principles.................
Looks like large head on top of carb is a diaphragm actuated by throttle-varied motor vacuum. Attached to it is what looks like it could be a fuel pump that's assisted by the diaphragm action, like the vacuum assist unit for power brakes for a car's master cylinder.
End of open black hose looks like it's been unattached a good while, likewise been unclamped since there's no marks. How important could it have been if not needed to run?
What's the green garden-hose-looking line, a fuel line?
Nipple on bottom of bowl has to be a drain, only fuel could be laying down in there that low. Guessing the slot-head screw in front of it opens it.

 

[KenMathisHD]

Knowing zero about Hammerhead, and based purely on mechanical principles.................
Looks like large head on top of carb is a diaphragm actuated by throttle-varied motor vacuum. Attached to it is what looks like it could be a fuel pump that's assisted by the diaphragm action, like the vacuum assist unit for power brakes for a car's master cylinder.
End of open black hose looks like it's been unattached a good while, likewise been unclamped since there's no marks. How important could it have been if not needed to run?
What's the green garden-hose-looking line, a fuel line?
Nipple on bottom of bowl has to be a drain, only fuel could be laying down in there that low. Guessing the slot-head screw in front of it opens it.

The green garden hose looking line is I think what the PO used for a fuel line, he had about 6 foot of it for some reason hooked up to the carb. I don’t plan on using it very long, but for now I’ve cut it down quite a bit so it’s running direct from the now cleaned fuel tank to the carb. Only 1 side was hooked up when I got it.

I’m not sure if it has a fuel pump or if it’s just gravity fed - the tank sits right above the carb so I was thinking it’s just gravity fed. But if the diaphragm is vacuum actuated, then it’s a safe bet that I’d need that line for it to allow fuel to flow through the carb to the chamber, yea? Or do I have that wrong? I haven’t done a lot with carbs, pretty much most of what I’ve worked on is EFI, and what isn’t I haven’t screwed around with fuel flow on.

 

[KenMathisHD]

Also, on a different note, I noticed that when cranking the motor, if it’s in gear, the wheels will spin. Am I right to assume that they shouldn’t be doing that while cranking, and that the clutch for the CVT (a centrifugal clutch, yea?) is probably seized/stuck? Cause it’s not supposed to engage until the engine reaches a certain speed, yea? When I picked it up the plastic cover that goes over the belt and that clutch was off, which makes me guess the PO was probably trying to figure out the same thing.

 

[madprofessor]

Only thing I'm completely sure of on that fuel system is that if you didn't put a fuel filter somehow in that garden hose between the tank and carb, you're asking to clog up or restrict some extremely tiny passages in the carb, recently cleaned tank or not.
About the gravity feed, I have a pulse fuel pump on mine to feed a thirsty .036 jet. Went to a lot of trouble when moving the tank to specially custom fit it (on rubber isolators, custom braces, etc.) just above the plane of the carb inlet. Supposedly didn't need to, but wanted a definite. As long as you're keeping your tank above the carb the way you are now, I don't think you can go wrong.
If your wheels are spinning with them jacked up off the floor, you don't know what's happening. If they're down on the ground and it's trying to run away from you, and it's not idling up too many rpm, yes there's a CVT problem.
Belt should be resting on the "shaft" between the 2 halves of the clutch (driver), and riding on the outside of the driven pulley. If the clutch is squeezing the belt and turning, the clutch is failing.
Others here can tell you how to take care of the clutch.

 

[Denny]

And for safety’s sake please don’t crank with engine in gear. A few years ago we had a guy who’s kart took off on him. The way he described it it sounded funny, but in real life it must have scared the tar out of him when it took off.

 

[KenMathisHD]

And for safety’s sake please don’t crank with engine in gear. A few years ago we had a guy who’s kart took off on him. The way he described it it sounded funny, but in real life it must have scared the tar out of him when it took off.

I put it in neutral after I noticed it doing that, I only try cranking it whilst in neutral now.

 

[KenMathisHD]

Only thing I'm completely sure of on that fuel system is that if you didn't put a fuel filter somehow in that garden hose between the tank and carb, you're asking to clog up or restrict some extremely tiny passages in the carb, recently cleaned tank or not.
About the gravity feed, I have a pulse fuel pump on mine to feed a thirsty .036 jet. Went to a lot of trouble when moving the tank to specially custom fit it (on rubber isolators, custom braces, etc.) just above the plane of the carb inlet. Supposedly didn't need to, but wanted a definite. As long as you're keeping your tank above the carb the way you are now, I don't think you can go wrong.
If your wheels are spinning with them jacked up off the floor, you don't know what's happening. If they're down on the ground and it's trying to run away from you, and it's not idling up too many rpm, yes there's a CVT problem.
Belt should be resting on the "shaft" between the 2 halves of the clutch (driver), and riding on the outside of the driven pulley. If the clutch is squeezing the belt and turning, the clutch is failing.
Others here can tell you how to take care of the clutch.

Wheels are down and contacting the bed, enough weight on them that I can’t turn them by hand. Guess I might be doing the clutch once I get it running. It ran for a little bit on starter fluid so I’m just trying to figure out the fuel flow issue before I start screwing with the clutch.

I’ve got a fuel filter installed inline. Garden hose is a little big for it though so I’ll probably go get some good sized line sooner than I was hoping if it starts leaking.

 

[madprofessor]

Starting fluid is like dumping pure ether down the throat. What your idle screw is set for is kind of irrelevant while the carb is breathing in explosive vapor instead of good old Earth-made air.
If the kart is trying to take off without anyone adding throttle to it while breathing in starting fluid, don't be surprised about it. The explosions in the cylinder at that time aren't representative of what your idle screw is set for. Get it running like you said, then consider the issues that show up after that.
Just an illustration: Back in my early 20's I tried the old "lighting the hairspray can's spray with a lighter" to see what it would do. Problem was I did it with starting fluid. From the driver's seat of my van, it burnt the window shades on my back doors. Like pure ether. Use sparingly.

 

[Denny]

Don’t quote me on this but I seem to remember at least on the Chinese scooters with that engine and carb there is a vacuum switch/valve deal that lets or helps the gas to flow when needed. I could be wrong? If I were you at this point I would pull off the carb. Remove all the rubber parts and store in safe place. Get a can of carb cleaner and torch tip cleaner and go at the carb. (Do not get carb cleaner on rubber parts.) or search out a replacement carburetor on Amazon or E-Pay. Before you burn out the starter. You know now it is at least capable of running and worthy of a couple of bucks to do so.

 

[KenMathisHD]

Don’t quote me on this but I seem to remember at least on the Chinese scooters with that engine and carb there is a vacuum switch/valve deal that lets or helps the gas to flow when needed. I could be wrong? If I were you at this point I would pull off the carb. Remove all the rubber parts and store in safe place. Get a can of carb cleaner and torch tip cleaner and go at the carb. (Do not get carb cleaner on rubber parts.) or search out a replacement carburetor on Amazon or E-Pay. Before you burn out the starter. You know now it is at least capable of running and worthy of a couple of bucks to do so.

The new carb I ordered for it came in yesterday afternoon finally, just very late in the day. And wouldn’t you know it - it has all of it’s little hoses! Big plus on that, even came with it’s own little fuel filter so now I’ve got an extra. I ordered it when I first started looking through the kart since the original was pretty gunky and had some stripped screws on the bottom for the bowl. I took the original off while cleaning the fuel tank and used some carb cleaner to blow through the passages I could get too to see if I could clean it up enough to get it running, but no dice. I’m gonna throw the new carb on it probably tomorrow when I have some time after work to mess with it again.

I should’ve asked this before, but I’m using regular 87 octane to try and get it running. Should I be using something higher? I was hoping to run it on the no-ethanol stuff QT has when it’s actually running so it doesn’t destroy the carb seals or gunk it up as bad if it has to sit at some point, but regular 87 is what I had in a jug when the starter fluid ran out. The 87 is fresh, I filled the jug up for a neighbor a few days before I started messing with the kart.

 

[KenMathisHD]

Starting fluid is like dumping pure ether down the throat. What your idle screw is set for is kind of irrelevant while the carb is breathing in explosive vapor instead of good old Earth-made air.
If the kart is trying to take off without anyone adding throttle to it while breathing in starting fluid, don't be surprised about it. The explosions in the cylinder at that time aren't representative of what your idle screw is set for. Get it running like you said, then consider the issues that show up after that.
Just an illustration: Back in my early 20's I tried the old "lighting the hairspray can's spray with a lighter" to see what it would do. Problem was I did it with starting fluid. From the driver's seat of my van, it burnt the window shades on my back doors. Like pure ether. Use sparingly.

Being in my 20’s now, a few years ago before having ever used the stuff, I tried using starter fluid to get a fire started in the fireplace in winter when some of our wood had gotten wet from rain a day or two before. I couldn’t find my charcoal lighter fluid or the gas bottles I usually have around, so starter fluid sounded a good alternative. I didn’t have most of my eyebrows or front hairline for a couple months after that and we had to clean the singe marks off the mantle face, but I got the fire started.

 

[Budget GoKart]

good job getting the fire started! my carb kept getting dirty because a dirty tank so it would run but die out after a little while till i rebuilt the carb