95 Skorpion Sport - fuel dripping from float bowl

[WaiNYC]

As detailed in a different thread, http://www.mzriders.com/viewtopic.php?f=3&t=8119 I recently took out the carburetor of a 1995 Skorpion Sport, cleaned it, and put it back on the bike. After reconnecting the fuel line, I noticed that fuel was dripping out of the overflow hose ([4] below).

But the dripping would stop when the engine was running. This led me to conclude that the float had been set too low. I thought I had set it right, to 25mm. But the dripping suggests to me that I should increase distance (a), below.

(Of course, I need to double check and see if I had made a measurement mistake last time around...)

Am I right with the diagnosis?

[edfmaniac]

Did you replace the float valve itself and is the spring inside the new valve strong enough to hold the floats up without compressing(when upside down of course)? You should be able to lower the floats down onto the pin sticking out of the valve without it retracting. Then check to make sure the pin will retract a little with added pressure on the floats to confirm the pin and spring are operating freely. Once you confirm that the pin is operating freely and is fully extended, make your measurements and adjustments to the tab on the float. If it still leaks from the overflow after that, you may have a bad seal between the valve and valve seat. You can check that by running fuel through the carb with the bowl off(in the right side up position). Gently hold the valve closed with the floats and hook up a length of fuel tubing full of fuel to the carb so gravity can do it's job and test the seal. It should stop the flow of fuel as soon as the valve makes contact, and not need the added pressure of the compression of the spring inside the valve.

Let me know if any of that doesn't make sense.

[edfmaniac]

And 25mm would be the maximum float height within the given range. 27 would give you more room between high tide and the vent tube level. Try 27mm if the float valve checks out.

[WaiNYC]

Did you replace the float valve itself and is the spring inside the new valve strong enough to hold the floats up without compressing(when upside down of course)?

I installed a new float valve and spring that came along in a carb repair kit.

You should be able to lower the floats down onto the pin sticking out of the valve without it retracting. Then check to make sure the pin will retract a little with added pressure on the floats to confirm the pin and spring are operating freely. Once you confirm that the pin is operating freely and is fully extended, make your measurements and adjustments to the tab on the float. If it still leaks from the overflow after that, you may have a bad seal between the valve and valve seat. You can check that by running fuel through the carb with the bowl off(in the right side up position). Gently hold the valve closed with the floats and hook up a length of fuel tubing to the carb so gravity can do it's job and test the seal. It should stop the flow of fuel as soon as the valve makes contact, and not need the added pressure of the compression of the spring inside the valve.

Let me know if any of that doesn't make sense.

I needa take the carb out again to check the above. But thanks for the tips

[WaiNYC]

I decided not to fix the fuel leakage for now. It's been three weeks since I started the restoration project, and I really, really just wanna get it to run and ride it I guess I just really need to remember turning the petcock off whenever I am off the bike and keep a tank of spare gas in the garage.

The bike's valve needs to be checked for clearance anyways, sometime shortly down the road... I figured after 2 to 3 K miles. I guess I will fix the leakage then.

[edfmaniac]

You should just do it right the first time, even if it takes half a dozen tries. The intake valves could have been done in a few minutes, even by a noob, and the float level can be verified without taking the carbs back off. If I'm not mistaken, there is a drain screw on the bowl. Take the line coming from that drain and hold it facing up next to the carb/bowl mating surface, then open the drain screw. The fuel will only come up as high as the fuel inside the bowl and it should be 6-8mm below that mating/gasket surface. I'd shoot for 8mm since you are having leakage issues. Just do it right.

[Chuck in Indiana]

There's never time to do it right, but always time to do it over.. BTDT.

[edfmaniac]

I'm a creature of habit AND the king of procrastination, so I had to overcome some serious mental obstacles when learning how to work on my bikes like a real mechanic would. Then I realized that if something goes wrong, something as simple as the chain coming off or a bearing going bad, it can have deadly consequences. You aren't out there on the road by yourself. If you have a mechanical failure in traffic, and it doesn't cause you to crash immediately, you still have to get off of the road without dying, and nobody is paying attention these days.

[basser23]

HAVE TO TOTALLY AGREE.....most all drivers here have short attention span and bad vision...central floriduh....thought I was the procrastination KIng...Tell ya bout it later....