The new ride

[klapool]

My son and I worked on this project over the weekend.

It ran like a charm until the front motor mount bolts pulled out of the case and twisted.

We spent the rest of the day running a new black wire from inside the case. straightening the rear wheel gear, putting a new tire and tube on and attempting to put new bolts back into the case. It looks like we are going to have to drill and tap the front mount to 5/16 24 tomorrow.

Here is a video of him taking it on its maiden voyage...

Motorized bicycle, maiden voyage - YouTube

 

[Nashville Kat]

Too bad about problems- but sure you'll get them fixed

Great ride and your son looks jazzed about it!

Is that 20 inch or 24 bike?

 

[wayne z]

Yea I think it happened the other way. The case twisted and and pulled the studs out. Fairly common on a fresh build unless special attention is given.

Opon installation or reinstallation, you should snug the rear mount first, then tap on the mount to work the engine down as low as possible with slight clearance with the chain guard or until the front mount jams against the front tube, whichever comes first.

If the front mount aint touchin the tube, you need to use some method to adapt it to take out the slack. Then tighten it all good.

Very important to fit the rear mount first, and re tighten everything after the first test run. And again after a few miles. And again every once in a while. Any movement or looseness at all and the motor will be pulled to the drive side by the chain tension from accellerating and decellerating or starting.
The next problematic thing is the chain tensioner. Many ways talked about here to minimise trouble. I've had good luck with using screen mesh sanding mediulm in the clamp area to increase fricton and eliminate movement into the spokes.
Break her in hard without high revs with whatever you use in yer weedeater but 24-1 ratio. after that 40-1 or even 50-1 aircooled 2 stroke oil will give you good service. Most ppl use way more oil than is really needed, for many unfounded old school reasons. thers use exotic synthetics. It all seems to work with these engines.

Hope I didnt ramble or preach to the choir too much.

 

[mapbike]

Yea I think it happened the other way. The case twisted and and pulled the studs out. Fairly common on a fresh build unless special attention is given.

Opon installation or reinstallation, you should snug the rear mount first, then tap on the mount to work the engine down as low as possible with slight clearance with the chain guard or until the front mount jams against the front tube, whichever comes first.

If the front mount aint touchin the tube, you need to use some method to adapt it to take out the slack. Then tighten it all good.

Very important to fit the rear mount first, and re tighten everything after the first test run. And again after a few miles. And again every once in a while. Any movement or looseness at all and the motor will be pulled to the drive side by the chain tension from accellerating and decellerating or starting.
The next problematic thing is the chain tensioner. Many ways talked about here to minimise trouble. I've had good luck with using screen mesh sanding mediulm in the clamp area to increase fricton and eliminate movement into the spokes.
Break her in hard without high revs with whatever you use in yer weedeater but 24-1 ratio. after that 40-1 or even 50-1 aircooled 2 stroke oil will give you good service. Most ppl use way more oil than is really needed, for many unfounded old school reasons. thers use exotic synthetics. It all seems to work with these engines.

Hope I didnt ramble or preach to the choir too much.

You said it very well in my opinion........I agree with you on all things explained here.

Only thing I do different is I replace the soft studs with grade 5 before I ever mount up an engine and I use blue loctite on every stud, mounting, carb. exhaust, these are the ones that will bite you in the butt many times and I want mine right the first time and then no more worries about them giving me static.

Peace, map

 

[kevinkrg6]

I tapped mine for 5/16. Works awesome.

 

[klapool]

Too bad about problems- but sure you'll get them fixed

Great ride and your son looks jazzed about it!

Is that 20 inch or 24 bike?

I dont have a clue!! It was the only cranny wally world had.

I know it has 26 inch rims because when the back tire skidded to a stop we stole the back tire off my wifes mountain bike and its a 26"

 

[klapool]

Yea I think it happened the other way. The case twisted and and pulled the studs out. Fairly common on a fresh build unless special attention is given.

Opon installation or reinstallation, you should snug the rear mount first, then tap on the mount to work the engine down as low as possible with slight clearance with the chain guard or until the front mount jams against the front tube, whichever comes first.

If the front mount aint touchin the tube, you need to use some method to adapt it to take out the slack. Then tighten it all good.

Very important to fit the rear mount first, and re tighten everything after the first test run. And again after a few miles. And again every once in a while. Any movement or looseness at all and the motor will be pulled to the drive side by the chain tension from accellerating and decellerating or starting.
The next problematic thing is the chain tensioner. Many ways talked about here to minimise trouble. I've had good luck with using screen mesh sanding mediulm in the clamp area to increase fricton and eliminate movement into the spokes.
Break her in hard without high revs with whatever you use in yer weedeater but 24-1 ratio. after that 40-1 or even 50-1 aircooled 2 stroke oil will give you good service. Most ppl use way more oil than is really needed, for many unfounded old school reasons. thers use exotic synthetics. It all seems to work with these engines.

Hope I didnt ramble or preach to the choir too much.

No rambling at all, I am so pumped about this new hobby I am trying to learn all I can about this thing. I will take off the tensioner and rough it up. I wonder if I could just spot weld it to the frame???

Thank you for taking the time for a newby!!!!

 

[klapool]

You said it very well in my opinion........I agree with you on all things explained here.

Only thing I do different is I replace the soft studs with grade 5 before I ever mount up an engine and I use blue loctite on every stud, mounting, carb. exhaust, these are the ones that will bite you in the butt many times and I want mine right the first time and then no more worries about them giving me static.

Peace, map

I will pick up some loctite today and change out the bolts to all grade 5. This winter when its cold and snowy I think we will change all of the mounting studs to 5/16".

Thank you!!!!

 

[klapool]

I tapped mine for 5/16. Works awesome.

did you go with course threads or fine threads?

 

[mapbike]

did you go with course threads or fine threads?

Personally I would go with coarse threads in the soft material these engine cases are made of.

As to the Idler/Tensioner being secured on the frame here is a link that has an example on each of the 2 pages that will give you an idea of how many of us secure the bracket to the frame so that it will not rotate into the spokes.

http://motorbicycling.com/f4/chain-tensioner-falling-into-spokes-mystery-19727.html

Here is a pic of mine on my Huffy bike.

Best wishes, Peace

Map

 

[concretepumper]

Great lookin' bike. Bummer about the bolts stripping themselves out. I have been wondering about the quality of these china kits. I have 3 going on 4 weed wacker/ chainsaw powered bikes all home fabbed. They work well but I have been looking @ these kits latley. Mostly for ideas. Are these kits junk? My bikes all take a little tweaking to make them right but each one is different. Are these engines all P.O.S.???

 

[mapbike]

Great lookin' bike. Bummer about the bolts stripping themselves out. I have been wondering about the quality of these china kits. I have 3 going on 4 weed wacker/ chainsaw powered bikes all home fabbed. They work well but I have been looking @ these kits latley. Mostly for ideas. Are these kits junk? My bikes all take a little tweaking to make them right but each one is different. Are these engines all P.O.S.???

These engines/kits can be a crap shoot, but the main problems most have is that they just don't set them up right from the start, mounting hardware is something that needs to be changed to higher grade bolts/studs, spark plug boot needs to be replaced and spark plug replaced as well SBP & Pirate both have good replacements for these, carb gaskets are not any good so they need to be replaced with a better gasket, I make my own from gasket material I get at a auto parts store like Auto Zone....

These engines/kits are a cheap chinese made product but can be made to perform very good and also hold up well if the right things are done to them in the begginning, I took a 12 mile trip today on one I built winter of 2009 it has about 1,300 miles on it now and still runs great, the only upgrades I've done to this engine is put an NGK B6HS Plug in it and a good NGK Plug Boot, tune the carb. and I made a free flowing exhaust for it,,it has the stock 41T sprocket on the wheel and will pull my 200LB back side up a pretty good hill and gain speed doing it.

My answer to the "junk" question can be finally summed up like this.....


If you junk/jerry rig one of these kits onto a bike, you will end up with a junky set up that will give you nothing but grief.

If you take the time to put one of these kits on a bike right, and upgrade the weak areas of the kit with better parts & pieces, you'll end up with a nice set up that you can really enjoy, will it still need some tinkering from time to time YES.... but you may end up like me and have a 1,300+ mile bike that hasn't had a wrench on it because of a failure in over a year, if it's done right this is easily done.

Get a kit from a reputable seller and do it right and you'll really enjoy that bike, the power and the potential speed of these littel engines are a lot of fun IMHO.



Peace, map

 

[concretepumper]

Thanks for the input Map! My builds need the same attention so I suppose I could make one of these work. Thanks Dude!

 

[mapbike]

Thanks for the input Map! My builds need the same attention so I suppose I could make one of these work. Thanks Dude!

Oh yeah, I'll bet you can make a good one up and really enjoy it, sorry for the long post, just wanted to give a bit of info. not only to you but for others who may be considering a build also.

I live in the country so my bikes really take a beating and are always very dusty and dirty, but I built them to hold up and they do, not fancy at all just solid built and very reliable.

I will be posting some pics of my oldest bike and what did to it today in the "what did you do to your bike today" thread, this bike is the 1300 mile china girl and she's still mighty sweet......hope this one never dies on me but when it does I hope I can get another one to run on this bike as good as this one does.

Peace, map