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Discussion Starter #1 (Edited)
So I disassembled the 700’s carbs, and cleaned all of the parts with vinegar and brake cleaner. They came out brilliant. I replaced one of the float needles (the spring on the little brass rod seemed stuck), and the other one seemed okay, so I left it. I cannot remember which one was new, because I cleaned the old one and that looked new afterwards too. Then I let the floats sit in the vinegar over night and cleaned those as well. Afterwards, I replaced all gaskets and put it back in. I broke one of the fuel nipples while trying to get the carb out, so that was replaced with the brass one. That was on the rear cylinder. I lubed that up with Vaseline and beat it in with a rubber mallet (gently, it went in snug, but alright). The bike fired right up. Once I turned the petcock to prime, the hose around the brass nipple started spraying gas. I put a hose clamp on, and it was fine. Now the engine becomes so bogged down with gas while sitting, I can pull the plug and send out a torrent of gas and it’ll start up, or try to turn it over several times to clear it. When that happens, there’s always a loud pop from the front cylinder before locking the engine, then it’ll clear the gas out of the coolant tube on the right.

Another interesting thing I noticed, is that if it is running and I tilt the bike far to the left, the bike wants to die. If I do the same on the right, it’s fine. My question is- what should I look for when I pull these bastards again? I poured in a full can of seafoam and have been riding like a jack ass, so everything should still be clean. Could the float be misaligned? I flicked it before installing, and it moved freely, the flog needle went into the tube easily.


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I'm confused by the pics, do you have a float issue or a massive coolant leak? The pics show a big leak from the coolant tube.

AS for the float, try cleaning the seat really well with a q-tip and do the same to the needle, then maybe press the needle into the seat and twist them together to sort of lap the surfaces together. Then check for free movement and float height. The needle should fall right out when the float isn't pushing it into the seat.
 

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Discussion Starter #3
If I don’t pull the spark plug and turn over the engine (a ton of gas shoots out), then it pushes coolant from the right side. When starting, the coolant that comes out appears miscolored but not oily. This was after the ride into work, which looked the same after letting it sit. The excess fuel appears to be mixing with the coolant.


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It can't be fuel and coolant mixing, fuel must just be splashing from somewhere else.

I'd watch for fuel in the oil, sounds like it's filling the cylinder with gas.
 

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Discussion Starter #5
So the cylinder getting flooded with gas - stuck float. Do you really adjust the float? Maybe I didn't get the rod seated correctly? I will flush the coolant tonight/tomorrow. Maybe there's a clog, because when turning over the engine after flooding, it pushes coolant out. Maybe not mutually inclusive.
 

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So the cylinder getting flooded with gas - stuck float. Do you really adjust the float? Maybe I didn't get the rod seated correctly? I will flush the coolant tonight/tomorrow. Maybe there's a clog, because when turning over the engine after flooding, it pushes coolant out. Maybe not mutually inclusive.
Probably just the float sticking, from misalignment or debris. Adjustment can make the fuel level too high/low, but if it was ok then suddenly isn't, it's not adjustment.

I'm with ubertalldude, I'm confused. There's just no connection to fuel and coolant. Unless the cylinder is cracked or gasket blown, and fuel is getting pushed in the coolant jackets.

You say coolant comes from the chrome tube at the engine case? If it pushes out of there when cranking, it must have a blown cylinder some way. I'm thinking/hoping that's not the case.
 

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Discussion Starter #7 (Edited)
Lets hope not! It seems to drive fine, the gauge never leaving the second hash mark. It runs a little warmer than the 750, but not outside of the normal range. I will pull the carb this weekend and try adjusting it. There was no fuel leak before I pulled the carbs when I first got, nor coolant leak. Could the increased pressure in the cylinder from the excess fuel cause this? Liquid always finds the weakest point. I didn't clean the tank or pull the petcock, so who knows what debris are in there. So much for flipping this! When I pulled the metal rod that holds the float needle, I just pulled it off, cleaned it, and tapped it back into place. I am unsure how to adjust the float, but I did what you had recommended last year, and made sure it was springy and moved freely. The float floated for 24 hours without sinking, but I did not check it for hairline cracks. There was no fluid inside when I pulled them from their bath and cleaned them. I will take better note when I go to start it today. The full can of seafoam seems to be working at least, as it is more responsive and occasionally gets puffs of black smoke with the back fires. I have noticed that the exhaust appears to have condensation on it. I didn't ear shave this one, and I plan on putting the sporster exhaust, since I am missing the left muffler past the heat shield. Could coolant be getting into the cylinder? Just spit balling here. It appears to drive fine, besides that I have used almost a full tank in 23 miles (revving it quite a bit, and keeping the rpms at 5k+ most of the time and A fuel leak)
 

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I wouldn't attempt adjustment until float/fuel level in the bowl is checked. There's a specific way to do this before the carbs are removed. (see manual) Hard, or impossible to do if the float is stuck.

Sometimes, careful but sharp whacks on the sides of the carb can free the float. Like a screwdriver handle and many quick raps to vibrate the carb.

Black smoke means excess fuel.

It will see excess pressure if the cylinder is filled with gas, but it has to have a blown gasket or cracked cylinder to push fuel into the coolant.

If it's getting coolant into the cylinder, you should see evidence of that on a spark plug. Looking steam cleaned or tiny water droplets on the plug.
 

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Discussion Starter #9
Okay, so to recap:
Step one -
Hard tap on side of bowl
Step two -
float fuel check before carbs are removed
Head gasket check - coolant in oil, spark plug condensation, and excessive heat?
If nothing is wrong with fuel float level - remove and try to remove and reset the float and needle? Not sure what to do about the coolant hose besides checking the gasket.
 

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If the cylinders are filling with gas, that sounds like a leaking petcock in addition to a bad float valve.
 
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If the cylinders are filling with gas, that sounds like a leaking petcock in addition to a bad float valve.
That's possible, would be the front cylinder.
 

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Discussion Starter #12
Surprisingly the petcock did not leak when I pulled the tank last time, despite a half full tank. Once I drain it down, I will clean the petcock just to be certain. You're right though, even with a stuck float, the petcock should stop the fuel. I think that is a bad diaphragm
 

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If leaking through the diaphragm, fuel will show up in the vacuum line.
 

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Discussion Starter #14
So I started up the bike, after letting it sit all day at work. It has about 1/4 of a tank, after filling it up 40 miles ago. It started pushing the coolant out of the silver tube on the right, and there was the multicolored oil look floating on the surface of the coolant on the ground. That being said, it could've picked up the gas because it was running down the side of the case. It was coming out pretty well for the first couple of miles. Again, the throttle response seems normal, albeit rich. Once I got home and parked it, no coolant spot, nor when I fired it up to put it in the garage 4 hours later. The final time of starting, it fired right up, no flooded cylinder or anything. The coolant reservoir is still 1/4 full. I will try starting it today, but it would seem that there could be a leak at a certain level? I am scratching my head, as the coolant and the flooded cylinder seem related. I pulled the rear plug (easy one to get to), it was wet and black (new plug), but no condensation.
 

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Could be that when you start with the cylinder flooded, the gas in the cylinder gets pressurized and pushes into the coolant system, thus causing excess pressure to build up, thus blowing past the coolant pipe o-ring. This situation would appear to be a bad head gasket if my theory is right.

It seems you have a bad fllooding problem, be it from the carb or the petcock vacuum outlet, AND you have a coolant leak at the coolant pipe, and possibly a gasket gone bad allowing liquid systems in the engine mixing where they shouldn't.
 

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Discussion Starter #16
That’s what I am leaning on as well. I am assuming a head gasket is an engine pull? This is the bike I intend on selling, so I don’t want to sink too much money (time I am okay with). After I pull the carbs again to check the float, I will see if the coolant issue continues. It could be a bad o-ring on the chrome tube. Do you have to pull the engine for that? Theoretically, if the coolant system is filling with gas (it appears to be), it should go to the reservoir, and then the ground


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Did you see liquid come from the tube, or just going by oily sheen you saw?

Just thinking maybe fuel washed it from farther up. ??

I think servicing the requires loosening the cover, but not pulling the engine. Check the manual though..
 

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Discussion Starter #18
The bright green coolant was leaking from where the chrome goes into the case. I did not see the oil (rainbow) sheen coming from the fluid leaving the chrome hose, only once it hit the ground. In the photo above, you can see it coming from where the tube enters the case.
 

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My bad, I think you told me that before and I'm just being daft.
 

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Discussion Starter #20
No worries! So replace the collars at the hose, and check the fuel level then potentially pull the carbs. What is the head gasket check? I can check the oil in the site glass, to see if it is a milkshake color...
 
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