A little help?

JerryHeglandWorks

New Member
Nov 21, 2008
5
0
0
Healdsburg, CA
Hi I'm using a cheap Chinese 80cc engine kit and sticking it on an ancient street bike frame.
I have got it running but there are a few problems,

1. the fuel valve leaks like a bad conspiracy

2. when I start it it starts going at around fifteen miles per hour, and there is 1/4" slack in the throttle. It would be nice if I could get that down a bit so I do not have to be pedaling at fifteen to safely start it.

3. the last time I tried to make it run when I stopped it the rear wheel froze up and no matter whether the clutch is in or not won't move at all.

4. all the writing on the bike is in Chinese so I was wondering if the choke is on with the lever up or down, and what the startup procedure with this type of bike is.

Would be much thankful for any advice at all, I'm kinda overwhelmed by it all.
 

jasonh

New Member
Jun 23, 2008
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Longmont, CO
1. wrap some teflon tape around the threads and screw it back in.

2. There are adjusters at the bottom of the throttle and at the top of the carb. You should be able to get most of the slack out. not sure if this will help your "15mph" problem though.

3. Pull off the cover of the drive sprocket. Most likely the chain got bunched up in there. Check your chain tension and alignment.

4. Choke on is up, choke off is down. My startup routine is put choke full on, pick up rear of bike via seat and spin the petals (clutch lever out please). Then put choke ~1/2 on and repeat. Motor should start. Adjust choke as necessary.

Hope that helps.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,611
419
83
Los Angeles, CA.
Question #2... what do you mean?
do you have to pedal it up to 15MPH to get it started?
or, once it's started, it races @ 15MPH??

To start most of my bikes, I put the choke 3/4 of the way on, pedal real fast & pop the clutch & keep pedaling... they usually start within 10-20 feet!
 

JerryHeglandWorks

New Member
Nov 21, 2008
5
0
0
Healdsburg, CA
Thank you all, these answers will solve many of my problems.
What I mean is that as soon as the bike's engine starts it immediately jumps to fifteen mph and takes off. This means that if you are pedaling at less than 15mph when you start it you will crash from the sudden acceleration.

Once again,
thanks to both of you.
 

1_2Mini

New Member
Oct 2, 2008
22
0
0
You probably got the same engine as me and I had similar problems at first. I recommend doing all of the following:

1) Put and o-ring inside the carb where it butts against engine intake...you likely have an air leak around the clamp like I did, this is why your choke doesn't do anything. This will allow you to properly set the idle speed using the idle adjustment screw.

2) When you have the carb removed look inside and work the throttle, the brass slide should go all the way up on full throttle and nearly all the way down...maybe 1/8" of a gap. If it doesn't go down all the way then either the slide is jammed up too high or like on mine the dowel pin that guides the slide is missing and the slide has rotated and gets caught on the idle screw. There is a 45 degree slot on the slide that the idle screw should fit inside.

3) If you feel you have far too much cable slack even after adjusting everything then you can remove some cable sheathing. I removed about 1/2 inch near the throttle cable inlet and wrapped it good with tape afterward. I have instantaneous throttle response now.

If you do all of this then you should be able to start your bike easily and adjust the idle speed down to where it doesn't push you hard at all. Currently, I have my idle set to where when clutch is engaged I go about 5 mph and when clutch is pulled the idle does not race up...it simply stays and a very low put put put.
 

Rogwillsie

New Member
Oct 28, 2008
30
0
0
Seattle, WA
I had the same problem of leaky fuel valve, used teflon tape and the gas dissolved it. After asking at the hardware, I used plumbers putty on the threads of the fuel valve and no more leaks.

The throttle/carborator problem is tricky. You have to make sure you have the carb assembled correctly. The sliding mechanism must be positioned so the slot goes through a very small indentation inside the wall of the carb. It took me about an hour to discover this when I assembled my kit. No good instructions.

You may have to adjust the clutch to get it to release, if your chain isn't jammed in the housing.

Have fun. Ask all your questions here, there are many experts. Not me.
 

hiker472

Member
Nov 6, 2008
654
2
18
Ontonagon County,Upper Michigan
make sure the slide is able to go all the way down inside the carb while everything is hooked up. You can do this by pulling the air cleaner off and looking inside it. If the slide doesn't look like it's able to slide all the way down, then the problem is the length of the cable housing......at least it was with mine.
I had to remove an inch off the housing to get enough cable so that it would be able to allow the slide to move farther down. Others have had this problem as well so it seems like a common quality control problem.
 

xPosTech

The Old Master Motorized Bicycle Builder
Oct 23, 2008
209
0
0
SETexas
Maybe someone will be kind enough to measure the correct length cable? Total length doesn't matter, just amount of cable sticking out of sheath with the other end snug. Then everybody could check it before installing the cable.

I think there are two types. One for metal grip one for plastic grips?

Ted
 

Norman

LORD VADER Moderator
Staff member
Jan 16, 2008
2,605
2
38
67
pampa texas
47mm of inside cable sticking out of the outer cable will get you in the ball park. measured from outer cable to the start of the cable ferrel (measurement does not include the cable ferrel).
an easy way to tell if cable is long enough and working the throttle correctly is to take the carb off the intake manifold and look at the throttle slide it should open all the way and close all the way adjustments for idle is made with the idle screw slack can be taken out of the cable by using the adjusters and either end of the throttle cable.
In bad cases as in too much slack or not enough I will make the cable the length I described and silver solder on a homemade end made out of copper wire/single strand phone wire wrapped around the cable and sliver soldered on.
I have this posted in the classic posts but the pictures are not the best.
Norman
 

JerryHeglandWorks

New Member
Nov 21, 2008
5
0
0
Healdsburg, CA
Thank you all so much, almost all of the problems with my bike have been ironed out due to you guys.

I still have a couple of questions:

1. what is the average life of these kits, in miles traveled?

2. i am 15 and seven months, is it legal for me to ride my bike in town in California with no license? I read the legislation but the politicians have me stumped, I can't make head or tails of it.

3. what are the specs on the white wire coming from the engine to power lights?

4. what is the best way to attach a crate to the back of my bike?

5. what are some good safety precautions (I need to sway my parents :) and yes, I do wear a helmet and I'm going to install lights.
 

hiker472

Member
Nov 6, 2008
654
2
18
Ontonagon County,Upper Michigan
Thank you all so much, almost all of the problems with my bike have been ironed out due to you guys.

I still have a couple of questions:

1. what is the average life of these kits, in miles traveled?

2. i am 15 and seven months, is it legal for me to ride my bike in town in California with no license? I read the legislation but the politicians have me stumped, I can't make head or tails of it.

3. what are the specs on the white wire coming from the engine to power lights?

4. what is the best way to attach a crate to the back of my bike?

5. what are some good safety precautions (I need to sway my parents :) and yes, I do wear a helmet and I'm going to install lights.
It's great to hear you got things on the smooth :D You've raised some good questions too and I'm sure there are more wizards of the wind here that can help you more than I can, but I'll try my best.

1) No one knows for sure, but with care it last a long time to come.
2) I don't know, but only guess that you will need a license.
3) 6 volts
4) Do you have a rack on the back? If not, get one or copy one off another one and build one, but they're fairly cheap if you keep your eyes open for one. If you do have a rack, you can bungy strap it on (like I do) or bolt it on.
5) Ride defensively, which means to always be aware of your surroundings, like who's in front, in back, to your left, and to your right. Is there a dog bolting out of a yard to meet you in the street? Is someone backing out of their driveway and most likely don't know you are there? ALWAYS know the enviornment in which you ride. ALWAYS assume that people are unaware of your presence. ALWAYS be on the lookout FOR ANYTHING that may cross your path! This way you will be able to avoid possible accidents and bad injuries.

I hope this helps. :bike2:
 

JerryHeglandWorks

New Member
Nov 21, 2008
5
0
0
Healdsburg, CA
Thanks a lot.
I've looked into the California laws a bit, and decided they are retarded. It turns out I might even need to get a motorcycle license. So far I've called the local police station twice. Once they said I did not need a license and the other time they said I needed an M1!

I am thoroughly disgusted with the US system of laws.
 

hiker472

Member
Nov 6, 2008
654
2
18
Ontonagon County,Upper Michigan
Sounds like the way Florida is when I lived there!
I think that as long as it's 50cc and under, at the most it'll be considered a moped, in which at the most all you need is a drivers license and because the HT's are unmarked you could use the "80cc" and if you wanted, you could engrave a nice "49cc" on the side of it and Johnny Flatfoot won't think twice about it:D

check out http://moped2.org/mstates.htm and see what they say :ride2:
 

2door

Moderator
Staff member
Sep 15, 2008
16,326
123
63
Littleton, Colorado
Jerry,
Hiker's safety suggestions are very good, Listen to the man and allow me to add one more.
Always ride as if other drivers don't see you. Never assume that the driver of a car coming out of a side street or driveway will yield to you. People seem to ignore bikes, even motorized ones and will pull out as if you're not there. Always assume you're invisible because that's how too many others see you. I always approach a cross street with caution for this reason. I was behind a girl who was on a pedal bike last weekend. She came to an intersection and had a green light to cross but a guy turning left from the opposite direction didn't yield to her and missed hitting her by inches. Real scary. I waited because I expected what happened to happen and stayed safely behind her and even yelled but she assumed she had the right of way. She did, but the other driver ignored her.
Have fun and be careful and we're all here to help if you have future problems.
Tom