Weed eater bike 25cc *need help tuning*

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yungmune

New Member
Aug 24, 2011
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oak lawn
I just finished moping my bike with a 25cc weed eater motor. It has no problems starting once i start pedaling but it bogs on me when i give it any throttle. Im guessing its not receiving enough fuel. What do you guys recommend i do to fix it. Also do you guys know if pepboys sell the tuning driver to adjust the hi and low fuel mixture?
 

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mapbike

Well-Known Member
Mar 14, 2010
5,502
109
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Central Area of Texas
I'm in the proccess of building a set up like yours myself and using what looks to be a very simular weed eater brand engine, neither of my engines have both high & low adjustments on the carb. one of them has either a high or a low with a plastic cap on it but I dont know which it is, I know that on some of these engines a set of needle nose pliers that have had the tip ground down real thin will get in to the adjustments like you may have on yours, a close up pic would really help, so we can see exactly what you have.

I have 2 of these weed eater engines that are like brand new so I hope I can get them set up real nice on a bike as well.

Peace, map



I just finished moping my bike with a 25cc weed eater motor. It has no problems starting once i start pedaling but it bogs on me when i give it any throttle. Im guessing its not receiving enough fuel. What do you guys recommend i do to fix it. Also do you guys know if pepboys sell the tuning driver to adjust the hi and low fuel mixture?
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
yungmune,

Just got back from Tractor Supply earlier and when I was there I looked at the newer model Weed Eaters like the one you have, I see what you mean about the High Low adjustments, looks to me like there probably is a special tool for adjusting them, but who knows where that could be got......

If it where me I would just grind the tip of some small needle nose pliers down so I could get a hold of the screw and turn it, just remember that very small adjustments can make a big difference so just make small adjustments.

Keep us posted on your progress.

Peace, map
 

yungmune

New Member
Aug 24, 2011
2
0
0
oak lawn
Hey map thanks for all your help. I was going to go with the plier idea to adjust the carburetor but i found this bit driver that looks like it would fit the adjuster bolts perfectly i just needed to grind the outside of it down to get it in there. I adjusted it the best i could. Seems like i adjusted it for high end power and its still weak after i give it a little throttle but anymore it runs really strong. i just rode it around now it it needs alittle pedal power to get going but thats fine with me. Im 150 pounds and with pedal power it can probably go alittle less than 20 mph but i still need to adjust it to put more pressure against the tire and peg because it is slipping when i run it at max throttle.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
Great, glad to hear you found a good way to adjust the carb.

As too the slipping, I will post a couple of pics tomorrow showing what I did to my Foot Peg/Roller, one thing that will help is if you will put a different tire on the rear of the bike that doesn't have the nobby type tread or at least has the nobs much closer together, it will give the roller more contact area than it has with those nobby tires with the big gap in between them, I'm going to my local bike shop tomorrow to pick up a couple inexpensive street tread tire for the Diomand Back BMX bike I'm gonna put my weed wacker on.

below are pics of the type I think would work great on the friction drive.

keep me posted on what you do to the bike and how it's working out, the weedwacker set up is something I'm playing with right now myself, it will be a bit rough built right now, but if it will push me down the road I'll be happy, the engine I'm using hasn't run in a couple of years, but I got it all cleaned up and running like a top today so I know I have a darn good little engine to start out with it seems.

best wishes!

Peace, map
 

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