weed eater chopper bike build

build progress update:

got the seat on, mounted and tested for strength...I think it looks awesomely ridiculous:

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I locked it onto the bike using a fire door hinge, and a leaf spring shackle...left the rear "truck" on to mount the shocks to...perfect fit...and easy access if I have to get to the engine or whatever:

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I was having trouble figuring where to mount the gas tank...so what better place than under the seat? and the top fill? I like it...

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only a few things left to do before the maiden voyage
reinstall pedals/chain
make a lift clutch
check tight on the many bolts

just picked up a sportscam that shoots video...figure if I hurry and finish the bike I can re join the vid section with some new footage...

questions, comments and feedback welcome(even negative)

thanks for looking
 
just a few more pics I finally got the time to upload

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thanks for looking

feedback accepted, opinions, questions and concerns, negative or positive...

enjoy
 
Congrats on a well thought out build! Lots of good ideas in this one. My only concern is roller size, and it is easy enough to make another. My favorites are the seat and the skate wheel support bearing. Genius! Looks like a fun ride!!
 
got to ride it today for about 5 minutes...cb2 your worries about roller size are unfounded sir, this thing pulled me up a 7% grade at about 12 mph, and did about 25 on the flats wot...

but all this was at half choke

I let the motor warm up for about 4-5 minutes before I jumped on...
pulled me downhill, uphill and on a flat, then, seems like it wont run with no choke...if I keep it about halfway choked it runs rough, then no choke and it dies, full choke doesn't do anything but make you out of breath trying to start this monstrosity

I was thinking fouled plug, changed it and no change
changed the spark plug wire too...nothing
new fuel lines
fresh premix

if I give it any gas it dies...

coil seems to spark 100% of the time everytime the magnet draws by the pickup, so I don't think its that

now it will only fire with a primer of carb cleaner, run for 15-20 seconds and die...im at a loss...might pull the engine and bring it to my local lawnmower joint...

it was awesome to ride it tho...once I get everything 100% ill take more pics, and even strap on my camera and strap the gps to the seat to see my speed range

but for now it wont run...

im sure its something stupidly simple that im missing...

any thoughts?


oh and I need to add some weight on the front due to the new seating postion the front tire bounces a bit and is actually quite scary...maybe a lawn tractor battery and run some lights...idk
 
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If the fuel contains ethanol and has been stood for any time, you should throw it away and get some fresh mix in. Also, the carb rubbers might need replacing. I keep reading here about pumper carbs failing due to the ethanol eating the rubber.
 
You mean the lil gaskets ? I had the carb apart before i started the build and all seemed intact...i have a walbro carb i might try...if it fits


But then again i might just take it to the mower shop, spend what it costs to make it perfect...thenn try to find another 16x3 tire

Ill check the rubbers and gaskets again tomorrow...
Took a dive trying to bump start it...roadrash, split finger, and a swollen knee
 
Glad you got it going. I wouldn't take it to a shop; they'll charge you a lot of money for doing nothing that you can't do yourself. Plus, pushing a guy on a bike might need a different adjustment than for weed-wacking.

If it needs choke to run then the carb is running lean. That means it will be low on power and could destroy the motor. If you have adjustment screws on the carb you will want to open (counterclockwise) the screw farthest away from the motor. Try a quarter turn at a time at most.
 
a_dam said:
Glad you got it going. I wouldn't take it to a shop; they'll charge you a lot of money for doing nothing that you can't do yourself. Plus, pushing a guy on a bike might need a different adjustment than for weed-wacking.

If it needs choke to run then the carb is running lean. That means it will be low on power and could destroy the motor. If you have adjustment screws on the carb you will want to open (counterclockwise) the screw farthest away from the motor. Try a quarter turn at a time at most.
Click to expand...

Only screw is idle adjust...gonna try 32:1 instead of 40:1...

I hope its that simple...

@IWW Yes, i agree...

Its sooooooo cool to watch the motor bounce on my contraption...i think the 46lb spring is good with 35psi in tires...

Had i not split my finger, id have kept on tweaking with it...
 
Ludwig is right on the carb. Ethanol attacks the flapper valves on the pumper side of the carb usually causing them to curl a bit and not sealing to pump fuel. Get you a kit from the local lawn mower shop(take the carb with you) and a can of spray carb cleaner. Pay VERY close attention to how it came apart. clean it and reassemble it EXACTLY as it came apart. There are usually several different gaskets to have to choose from in the kit. Choose CAREFULLY, differences can be subtle. Done right you should be up and running. DONT run 32:1 Run a good synthetic 50:1.
 
cannonball2 said:
Pay VERY close attention to how it came apart. clean it and reassemble it EXACTLY as it came apart. There are usually several different gaskets to have to choose from in the kit. Choose CAREFULLY, differences can be subtle.
Click to expand...

haha...well me being who I am, I decided to just have the lawnmower place do the rebuild for $23

or from a different place the rebuild kit is $29 and a new carb would be $60+

I decided $23 was fair enough to not have to mess up the carb and be back at square one.

should have it back in 2-3 days...gives me time to make a lift lever, and button up everything 100%

when I told the lawnmower tech what the motor was on he laughed and said hed never heard of anything so ridiculous...

then I showed him pics, and he was in awe...

may have swayed another person into the motorized bicycle world...he was muttering something like" I wish I had something that funky looking" as he was walking away...

made me smile...

pics on progress when progress is made...

thanks for looking
 
well got the carb back finally...

still being a pita...only runs half choke, give it gas it dies,,,

thats with the rebuild from a proffessional shop...

i also took another fall trying to run start it...

one more fall for me if its still not running im gonna sell it...

idk what else to try...could a 25 lb spring be too much tension? stopping it from running right?

fresh gas perfect mix...idk what the issue is...i tried a new coil, no go, new plug, nope...

any suggestions, before i pull the motor and bring the entire thing to that same shop to shove it in their face and say u didnt even rebuild my carb, held it for 6 weeks and charged me 25 bucks...argghh
 
New carb is probably in order. Some just cant be cleaned. Check the carb body for #s, then check ebay. I have found new carbs for less than $20.
 
Hey Wickedest1, don't give up just yet.

You've posted lots of good pics, but I haven't caught one of the carb yet.
(maybe there's one I missed)

Is it a Walbro or Zama?

If it runs on half choke, then it must actually be pumping fuel. Something might still be partly clogged or not working properly, but there's still hope.

I bought an old Echo (top of the line when new) weedwacker from a guy at a garage sale. He told me that it was good, but the carb needed a rebuild. He messed with it and couldn't get it to pump. I cleaned it a little and figured he was right. I bought the cheap rebuild kit (about ten bucks) and before I replaced any parts I thought I would try extra hard to clean everything out.

The side of the carb with one big screw in the center (opposite the primer bulb, if there is one). Remove that screw and carefully separate that plate from the carb body. The gasket/flapper thing will usually come off with (stick to) the plate. If not, carefully peel that off the carb body. Flush every hole out with blasts of carb cleaner. I prefer Gumout. Other brands seem to be all acetone, which evaporates too fast. Gumout seems to have a good balance of petroleum distillates.

There should be a round cavity about 1/4 diameter with a very fine screen in it. I usually use a sewing needle to remove the screen. Clean the screen. Blast out the orifice under the screen. My carbs all have high/low idle adjustment screws. I remove them both before flushing the carb. Sometimes I also blast a little compressed air across the metal parts, but you have to be careful. Reassemble.

Anyway, the carb I thought needed a rebuild or might be junk, works fine after a very thorough cleaning.

Post pics of your carb if you can. Also, if "it only runs on half choke", that still means it's not getting enough fuel. Have you checked for air leak between carb and engine?

Cannonball2 might be (usually is) right. Carb might be beyond fixing. I'm the kind of hardhead that would work hard for 30 hours trying to fix something that I could buy new for $20. I like to learn - from success and failure.

Sorry for the neverending post. Show us your carb. Don't be afraid to work on it yourself before you throw it away.
 
its a zama carb, an earlier model apparently because nobody can get the rebuild kit in under 7 weeks...prob is already went that route, proffessionally at that, only to still have these issues...

no air leaks at carb to motor, head to crankcase, exhaust is clear, new coil...i just am completely out of money and cannot afford to buy another carb

which sux

plus ive taken too many falls starting it...very very awkward under power

its got brand new gas lines with a custom petcock(90* cable housing)
fuel flows perfectly...

id have to agree at this point with cb2 about some carbs just being beyond salvation...

id guess if anyone here wanted to pick this up id give it to you for a very excellent price...

pm me if interested
 
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