Need carburetor help with my mini bike

[BuickMike]

I have a '71 Honda Trail 70 that I just got running. It starts great, but will only run if I keep the choke closed and the fuel mixture screw all the way in. I cleaned up the carb pretty good, but the float bowl adjustment was questionable. I replaced it with an unmolested one from my Trail 90. (Same part) I called a Honda dealership for the correct float bowl height and they said 20mm. I connected a clear tube to the drain and looped it up to the float bowl to check the level. It was 20mm lower than where the bowl assy met the carb body. Fired it up and the same problem exists. I rode it around the block and checked the level again. This time it sat about 5mm lower than where the 2 halves meet.

Am I checking the float level correctly?? I assumed this is how to check the float level, but I could be way off. Any help would be greatly appreciated.

The thing fires right up and idles great BTW, it just seems like it's running lean since it dies if I open the choke.

 

[turbo2nr]

Clogged filter in petcock? Clogged jet in carb? Air leak? Float level should not really be a problem when just sitting in a driveway and reving. The float level becomes more important when you are climbing/ decending hills, turning sharp, etc. Double check fuel lines for small cracks, holes.

 

[John Larkin]

Sounds like the main jet is clogged and maybe an air bleed as well. Just guessing. Don't they have a tiny pencil style fuel filter? Maybe that is stopped up too. I have a Mini Trail 50 in pieces on a shelf that I haven't begun a resto on. Everyone thinks I'm nutz; I like it.

 

[turbo2nr]

Some people go nutz about those things. I have a 1987 YAMAHA YSR 50. Ever seen one of those. I put a liquid cooled sixspeed racing motor in it. It will go about 103MPH. Tiny little bike. www.ysr50.com www.teamcalamari.com

 

[BuickMike]

Fuel lines are new. I cleaned up the carb before using it. The filter is new. I did some Google searching last night and found some other possibilities. It looks like I may be missing spirings and possibly o rings off of my bleeder screws on the side of the carb. I also neglected to make shre the float bowl vent wasn't clogged. I'll check the vent and see what the screws on my Trail 90 have.

 

[leo wagstaff]

i had a trail 70 from twelve years old well into my late teens and i have to tell you that the fuel system is VERY sensitive! just run some cleaner like xylene through it and change the spark plug often. adjust your idle to where it likes it the most and stay with it. the way the fuel system is set up is that the smallest grit of dirt any kind will play havoc how the bike runs. in short they are a pita but fun to ride. good luck!

 

[wlaukaitis]

well, that is strange. Normally if you need to have the choke closed all the time, the gas is being plugged up somewhere and it is not getting any gas. But then you say you have the mixture all the way in basically closing off the gas alltogether. I thought you check the float height by having the bowl off and having the float pointing up. The you usually need to measure from the carb surface to the top of the float.

How do all the needles look? How about the seats?