Good day
I'm at my wits end with this carb on my Blaster. It leaks petrol from the overflow no matter what I do.
Here is what I have done:
-The toothpaste trick with the old needle and seat valve
-Replaced the needle and seat
-Put the old needle back with the new seat (I put the new needle back again)
-I have adjusted the floats to every conceivable setting
-I have checked the overflow screw and it seems to be good
I eventually resorted to making the fuel bowl halfway full of fuel putting it back onto the carb and blowing into the fuel inlet to test if it leaks, if it does I simply adjust the tang on the float bowl so it no longer leaks.
I eventually got it perfect set in, where the bike wouldn't starve of fuel while idling or when speeding it won't bog down due to fuel starvation. It works fine for about one ride or engine start and then it starts overflowing again and bogging down at times for some odd reason due to maybe fuel starvation or something? When I ride and pull in the clutch so it disengages the revs go really high as if it starves from fuel.
If I had to stop the engine it would be a matter of seconds then it would look like the fuel is just coming directly from the tank out of the overflow, that's how much it leaks.
I can set the float numerous times and get it dialed in perfectly and this cycle would repeat itself over and over.
My theory:
The people I initially bought the bike from had no clue about maintaining it or even what kind of bike it was. They sold it due to this problem of it leaking from the overflow and they not having the expertise or money to have it fixed. They had a really scrappy mechanic work on it, I can see from the work he did on it actually. Nothing major, just very lax maintenance and poor workmanship where he did work. The old seat had a very sizable scratch in it probably from someone sticking a screw driver in there and trying to clean it out. They actually removed the oil light's wire so it would stop shining instead of just filling up the premix tank...
The float was definitely tampered with and the tang bends far too easy, I can literally bend it with my fingers applying almost no pressure. I think the tang is worn out to the point where it adjusts itself every time the fuel level rises in the bowl. The old seat had a very sizable scratch in it probably from someone sticking a screw driver in there and trying to clean it out.
Something else that I remarked is that the color of the bowl is a slightly lighter color than the rest of the carb, which I think may be indicative of it not having the original bowl on it and potentially having either a defective or wrong size bowl on it if this even is a thing. Which may lead the float to stick at times prompting the either fuel overflow or starvation due to the float not being able to travel as much as it should.
I want to get a rebuild kit, but I don't see a point in replacing the jets and everything else if this is likely a float issue or something that can be fixed without having to rebuild the carb.
The carb seems to be stock, there is no performance exhaust on it and the airbox cover is still on. When it does work nicely, it idle's really nicely but sometimes when I take off it feels like it's limiting the revs(maybe more related to the tors system?) however when I switch to second gear it pulls like a beast.
I can also upload photos of the carb and the bowl internals if need be. I'm fairly new to these Mikuni's maybe there is something obvious missing that I'm not aware of.
Any form of advice would be greatly appreciated!
I'm at my wits end with this carb on my Blaster. It leaks petrol from the overflow no matter what I do.
Here is what I have done:
-The toothpaste trick with the old needle and seat valve
-Replaced the needle and seat
-Put the old needle back with the new seat (I put the new needle back again)
-I have adjusted the floats to every conceivable setting
-I have checked the overflow screw and it seems to be good
I eventually resorted to making the fuel bowl halfway full of fuel putting it back onto the carb and blowing into the fuel inlet to test if it leaks, if it does I simply adjust the tang on the float bowl so it no longer leaks.
I eventually got it perfect set in, where the bike wouldn't starve of fuel while idling or when speeding it won't bog down due to fuel starvation. It works fine for about one ride or engine start and then it starts overflowing again and bogging down at times for some odd reason due to maybe fuel starvation or something? When I ride and pull in the clutch so it disengages the revs go really high as if it starves from fuel.
If I had to stop the engine it would be a matter of seconds then it would look like the fuel is just coming directly from the tank out of the overflow, that's how much it leaks.
I can set the float numerous times and get it dialed in perfectly and this cycle would repeat itself over and over.
My theory:
The people I initially bought the bike from had no clue about maintaining it or even what kind of bike it was. They sold it due to this problem of it leaking from the overflow and they not having the expertise or money to have it fixed. They had a really scrappy mechanic work on it, I can see from the work he did on it actually. Nothing major, just very lax maintenance and poor workmanship where he did work. The old seat had a very sizable scratch in it probably from someone sticking a screw driver in there and trying to clean it out. They actually removed the oil light's wire so it would stop shining instead of just filling up the premix tank...
The float was definitely tampered with and the tang bends far too easy, I can literally bend it with my fingers applying almost no pressure. I think the tang is worn out to the point where it adjusts itself every time the fuel level rises in the bowl. The old seat had a very sizable scratch in it probably from someone sticking a screw driver in there and trying to clean it out.
Something else that I remarked is that the color of the bowl is a slightly lighter color than the rest of the carb, which I think may be indicative of it not having the original bowl on it and potentially having either a defective or wrong size bowl on it if this even is a thing. Which may lead the float to stick at times prompting the either fuel overflow or starvation due to the float not being able to travel as much as it should.
I want to get a rebuild kit, but I don't see a point in replacing the jets and everything else if this is likely a float issue or something that can be fixed without having to rebuild the carb.
The carb seems to be stock, there is no performance exhaust on it and the airbox cover is still on. When it does work nicely, it idle's really nicely but sometimes when I take off it feels like it's limiting the revs(maybe more related to the tors system?) however when I switch to second gear it pulls like a beast.
I can also upload photos of the carb and the bowl internals if need be. I'm fairly new to these Mikuni's maybe there is something obvious missing that I'm not aware of.
Any form of advice would be greatly appreciated!