28mph to 22mph? 80cc chinese

[solitus3989]

My motor will rev like nuts if I forget to open the fuel line, on the last few drops of gas in the carb it will burn wide open. Even with no throttle. Something is not adjusted properly in your carb!

ok... but the only adjuster on the carb is that idler screw. and we have tried everything from 1.5 turns to 4.5 turns out and it doesn't make a bit of difference in the speed. it's about about 2 - 2.5? right now and it runs excellent when i close the fuel line.

 

[pedalpower]

i am thinking with a 20:1 mixture and with your gearing (26" wheels and 44 tooth) you are probably fowling the plug above 22mph. what plug are you using? what gap? what oil do you use? have you upgraded the plug wire?

toss your mix and go to a 30-32:1 ratio?
rebuild your carb or get a new one? 5 tanks at 20:1, you've probably got something where it shouldn't be.

you should be able to kill a warm engine with full choke, make sure clip is on stock 2nd position from the top, make sure needle tip is clean and not nicked or something?

whew, have you systematically eliminated anything? heck, maybe your clutch is slipping.

 

[lildeezul]

sorry for this hijacking.


but where can i find a effecient speedometer..???/

Also, my fuel filter is upside down according to the previous pictures.

Is that a problem.. The arrow on my fuel filter points up toward my tank, should it point down toward my carbreautor

 

[pedalpower]

sorry for this hijacking.


but where can i find a effecient speedometer..???/



Also, my fuel filter is upside down according to the previous pictures.

Is that a problem.. The arrow on my fuel filter points up toward my tank, should it point down toward my carbreautor

speedo at your local bike shop-cateye astrale 8

when your filter says "flow----->" what do you think that means?
get a new one.

 

[solitus3989]

sorry for this hijacking.


but where can i find a effecient speedometer..???/

Also, my fuel filter is upside down according to the previous pictures.

Is that a problem.. The arrow on my fuel filter points up toward my tank, should it point down toward my carbreautor

mine is probably not the most efficient. but i just went to fleet farm and bought a bike speedometer. it has a backlight for at night, even. didn't trust the wireless one.

i believe the arrow signifies flow of fuel. so down is correct.

 

[solitus3989]

i am thinking with a 20:1 mixture and with your gearing (26" wheels and 44 tooth) you are probably fowling the plug above 22mph. what plug are you using? what gap? what oil do you use? have you upgraded the plug wire?

toss your mix and go to a 30-32:1 ratio?
rebuild your carb or get a new one? 5 tanks at 20:1, you've probably got something where it shouldn't be.

you should be able to kill a warm engine with full choke, make sure clip is on stock 2nd position from the top, make sure needle tip is clean and not nicked or something?

whew, have you systematically eliminated anything? heck, maybe your clutch is slipping.

my plug is NGK-B6HS and i tried swapping that and the stock one several times. not the problem. didn't touch gap on stock, gapped to .20 on the NGK.

my plug wire is one i found in my garage. also tried swapping that one with the stock one. not the problem.

instructions said to go 20:1 after first tank of 16:1.

i will probably go to like a 30:1 on next tank?

oil im using is something i picked up at fleet farm. Phillips 66 Injex TC-W3 two stroke motor oil.

and why would my clutch be slipping? i don't think so. i know it's fully engaged when the clutch is released.

 

[pedalpower]

and why would my clutch be slipping? i don't think so. i know it's fully engaged when the clutch is released.

sorry, I'm getting punchy. do you have a spare exhaust pipe to try? clogging?

I'm trying to find the rpm calculator for our HTs for a given wheel and sprocket:

http://www.sheldonbrown.com/gears/

your gear ratio (26x2.125 10x44 gears): 5.9

22 mph sounds pretty good for your ratio. at 28 mph you must be rapping it out buddy.

 

[solitus3989]

sorry, I'm getting punchy. do you have a spare exhaust pipe to try? clogging?

I'm trying to find the rpm calculator for our HTs for a given wheel and sprocket:

http://www.sheldonbrown.com/gears/

your gear ratio (26x2.125 10x44 gears): 5.9

22 mph sounds pretty good for your ratio. at 28 mph you must be rapping it out buddy.

i don't want to go 28mph, though. but i want to at least be able to cruise at 25mph like i used to be able to?

so why was i able to do it before, but not now?

if i had never been able to go faster than 22mph, then id believe you... but the fact that it was fully capable of a 25mph cruise makes me believe that there is something wrong with the fuel or something.

like i said, when i close the petcock, i have all my power back. 25mph-28mph whatever. when i open it, i crawl along at 18-22 mph, depending on hills. it just has no power.

 

[relaxxx]

Have you made sure throttle needle has full movement. I think your answer lies in three words: rebuild your carb !!

 

[Hawaii_Ed]

I am not a pro at this, here is my WAG at it:
- If it picks up closing the petcock, mebbe the float is too low or the needle valve is stuck partially open. Since you have stopped the flow coming in, the engine goes back to lean, and runs better.

As listed above, I'd rebuild the carb or swap for a replacement.