lazylightning@mail.r
Active Member
Hi,
I've done alot of researching and I know the only possible reasons for my problem, just thought I'd try and get some feedback.
So when I open her up, full throttle at once, it responds pretty fast. Pretty good torque for all stock F-80(66cc)-(except for NGK B6HS plug). 35 tooth rear sprocket, so top end is not bad. I have no problem on steep hills if I peddle hard in the proper gear. But the strange thing is that about ten seconds after winding her up, it starts to cut out....in little spurts and then it bogs down and dies if I keep holding the throttle wide open. Exactly the same way it does if I turn off the fuel and wind her out. Okay, this is a no brainer right? I even quickly removed the plug to make sure it's not soaked, nope, as close to dry as just a little oily can be (still using 16:1 at about 350 km).
I have checked the fuel flow rate from the end of the hose after the inline paper filter cyclinder and it flows to the carb inlet at a good rate, or so it seems. I'm sure it's more than enough for that little pin hole of a jet, lol! I have adjusted my float, and I really cant get it any higher because of the push pin that is supposed to push down the float and drive fuel up and into the barrel. I've read 21mm float height here, and my float is so thick, plus the 4 mm length of that push pin pointing down. There is just no way I can get that outer(lower) float edge to be 21mm from the mating surface of the carb to float bowl. It's probably about 25mm. Geeze the float is so fat, it's about 20mm thick. I'll do an exact measurement when I pull it out again soon. I'm thinking of how to bend that tang so that it just barely closes the flow needle-valve before the float bottoms out on that push pin end. But it's already 1 mm from it now. WTF is with that? Can that float be sticking on the outside of the jet tube so regularly? How can that inflow needle-cone valve be sticking closed? If I keep running it, it takes a long time to refill, if I turn it off for a second (10 seconds), then the bowl is full of gas again, enough to wind her out for another ten seconds or so. Why could that inflow valve be so restricting the inflow? Maybe it was mis-machined and they assemble carbs with such cone valves with absolute disregard to the size allowances that should be obeyed in assembling a carb of this type? Or maybe the seat/brass screw in inlet tube has too much meat on/in it?
Just food for thought.
Thanks in advance for your ideas,
Paul
I've done alot of researching and I know the only possible reasons for my problem, just thought I'd try and get some feedback.
So when I open her up, full throttle at once, it responds pretty fast. Pretty good torque for all stock F-80(66cc)-(except for NGK B6HS plug). 35 tooth rear sprocket, so top end is not bad. I have no problem on steep hills if I peddle hard in the proper gear. But the strange thing is that about ten seconds after winding her up, it starts to cut out....in little spurts and then it bogs down and dies if I keep holding the throttle wide open. Exactly the same way it does if I turn off the fuel and wind her out. Okay, this is a no brainer right? I even quickly removed the plug to make sure it's not soaked, nope, as close to dry as just a little oily can be (still using 16:1 at about 350 km).
I have checked the fuel flow rate from the end of the hose after the inline paper filter cyclinder and it flows to the carb inlet at a good rate, or so it seems. I'm sure it's more than enough for that little pin hole of a jet, lol! I have adjusted my float, and I really cant get it any higher because of the push pin that is supposed to push down the float and drive fuel up and into the barrel. I've read 21mm float height here, and my float is so thick, plus the 4 mm length of that push pin pointing down. There is just no way I can get that outer(lower) float edge to be 21mm from the mating surface of the carb to float bowl. It's probably about 25mm. Geeze the float is so fat, it's about 20mm thick. I'll do an exact measurement when I pull it out again soon. I'm thinking of how to bend that tang so that it just barely closes the flow needle-valve before the float bottoms out on that push pin end. But it's already 1 mm from it now. WTF is with that? Can that float be sticking on the outside of the jet tube so regularly? How can that inflow needle-cone valve be sticking closed? If I keep running it, it takes a long time to refill, if I turn it off for a second (10 seconds), then the bowl is full of gas again, enough to wind her out for another ten seconds or so. Why could that inflow valve be so restricting the inflow? Maybe it was mis-machined and they assemble carbs with such cone valves with absolute disregard to the size allowances that should be obeyed in assembling a carb of this type? Or maybe the seat/brass screw in inlet tube has too much meat on/in it?
Just food for thought.
Thanks in advance for your ideas,
Paul
Last edited: