How to Maintain a Motorised Bicycle

GoldenMotor.com
Mar 5, 2014
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Eastwood
Hi everyone,

I made a motorised bike quite a while ago and I found that I had no room for it anymore so I took it to one of friends houses in the bush where he had room to store it in his shed.

When I next get to use it what maintenance should I perform on it and is their a maintenance schedule I should be following.

Also I started off with 16:1 fuel and I have almost used 5 litre's of it, from a jerry can, after I run of the 5 litre 16:1 fuel what ratio should I go to?

Thank you in advance
 
Mar 5, 2014
114
0
16
Eastwood
It is alright if I finish off the 16:1 fuel because I don't want to waste it, or should I change the fuel.

I am just using 2 stroke oil that I buy in a 200mL bottle or something like that.

Would I use 24:1 or go higher.

What can I do about maintenance for the bike?

Thank you in advance
 

BarelyAWake

New Member
Jul 21, 2009
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Maine
Try whatever quality air-cooled two stroke oil you like, mixed to whatever ratio that oil manufacturer recommends for their product - whatever that may be, it's far better then what the "instructions" call for lol

As for maintaining the bicycle itself, it's no different then any pedal bicycle 'cept that maintenance is going to be at least twice as frequent due to the additional speed & weight, which if even decent quality components are used is still minor... the typical tires, chain & brakes thing - wear items but not unduly so.
 
Mar 5, 2014
114
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Eastwood
Sorry if I sound persistent but could you please give me a list of what to check on the engine and bike to make sure it is all working and clean.

Thanks for the advice on the ratio, that surprises me.

Thank you in advance
 

BarelyAWake

New Member
Jul 21, 2009
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Maine
...and I truly don't mean to sound dismissive when I say: If it's dirty, clean it. If it's worn, replace it. If it's dry, lube it... unless it's s'posed to be, then jus' enjoy it lol

It's not that I'm belittling the importance, rather hoping to illustrate the wonderful simplicity of bicycles & these motors as well - there's jus' not that much to fix. Should you encounter a specific problem however, without a doubt it's been covered in painstaking detail somewhere on the forum, as well as folks that are happy to help w/such.

Jus' for familiarity, here's an "animation of engine breakdown" vid;
http://motorbicycling.com/showthread.php?t=56170

...& this section is a pretty good presentation of the most common problems with bikes & motors alike;
http://motorbicycling.com/forumdisplay.php?f=34

As for ratio - we've folks that run the 16:1 suggested by the "instructions" but our best guess is that's possibly due to the rarity of actual two cycle oil in some remote regions the motor was originally designed for (1940's Russia is most likely) & jus' passed on w/the Chinese clones. The typical two stroke oil ratios are usually 32:1 with basic non synthetic, 50:1 & even 100:1 with advanced, quality synthetics... user preference prevails ;)
 
Last edited:
Mar 5, 2014
114
0
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Eastwood
First of all, that video is awesome. I reckon I could make a the whole engine in 10 mins if I had the parts!

Thanks for all the info, but one last questions about the mounting studs that attach to bicycle frame, what should I torque them to, FYI I have helicoiled the mounting threads in my engine because they were stripped. Because I don't want to strip them again so I want to know how tight I can go before it is overtight.

Thank you in advance
 

crassius

Well-Known Member
Sep 30, 2012
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that question can have a few answers since not all engines are mounted the same way due to diffs in the frames they're attached to

if the rear mounting studs are nicely perpendicular to the frame, and the front mount was measured just right to support the weight without pulling the engine away from the rear mount, you'll find that it takes very little torque on the studs to hold the engine tight enough so that trying to push/pull the top of the engine left/right in the frame will give no movement whatsoever

the goal is not to reach a certain torque, but to keep the engine from moving under load

note that the studs will stretch a bit from time to time, so re-tightening is often needed

if the mounts weren't put on correctly, one may often strip the studs before the engine becomes stable
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
I agree with crassius, to a point regarding torque values. Yes, you want them tight enough to keep the engine where it's supposed to stay but you do not want to overtighten the fasteners. That is why I recommend using a torque wrench and not exceeding about 60 inch pounds on those 6mm studs/nuts.
"Tight enough" might be too tight and you don't want to replace a heli-coil, believe me.

Tom
 

Davezilla

New Member
Mar 15, 2014
2,705
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San Antonio Texas
I'll also agree on torquing everything with a torque wrench, it's just too easy to over torque stuff and snap bolts or strip threads, Harbor freight sells one that's perfect for these at a really decent price.
I also like to use the Blue locktite on stuff to keep the bolts and nuts from working their way loose since everything needs to be torqued at fairly low values.
Helicoils are also a really good idea for all the areas that have aluminum threads since the helicoils won't wear out like the aluminum will, but like mentioned above, you still don't want to over torque and have to replace a helicoil.
 

crassius

Well-Known Member
Sep 30, 2012
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proper torque will make the stud tight, but if the noob depends on that rather than on having the engine tight, he'll end up with half a chain wrapped around his leg
 

KCvale

Well-Known Member
Feb 28, 2010
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Phoenix,AZ
easier to just drain it
I agree.
Start it up, shut the fuel off and let the engine burn everything out, then drain the rest of the tank into a can.

You didn't state a time frame but gas has pretty short shelf life, like 3 months before it losses the ability to create gas vapor which is all that matters.

You can throw a lit match into liquid gas but if it can't make vapors it just puts the flame out because liquid gas don't burn.
No vapors, no joy starting it ;-}

I find 32:1 with off the shelf auto store 2-stroke oil to work great.
What you want is the highest ratio can go but still lube your engine bearings because everything in your fuel that does not vaporize and explode is just waste.
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado

Dan

Staff
May 25, 2008
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Moosylvania
Seems like a lot to do when a few cents worth of mix will work and ya don't have to go threw all that and then refuel when ya do want to ride.

I used to do the drain, run thing every fall on all our lawn equipment. Now just use a stabilizer and everything starts fine in the spring. Just what works for me.

But I am lazy and pressed for time.
 

crassius

Well-Known Member
Sep 30, 2012
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USA
dead gas is great for cleaning these things - when a bike comes in & I don't like the smell of the fuel or I can't tell the mix from the color, it goes into the dead gas tank and all motors get cleaned nicely before going out