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Motorized Mountain Bikes and Road Bikes Motorize a full suspension mountain bike to get a smother ride or for a little more speed try motorized road bicycles. This section is for sharing ideas on motorizing your mountain and road bikes.

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  #1  
Old 08-22-2016, 01:31 AM
2Slow4U 2Slow4U is offline
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Default Redbox Racer post build build thread

I've had this built for a while but i'ts been collecting dust for at least 6 months.

The thing about hobbies for me is that I'll either be completely obsessed or not care at all and right now I'm obsessed again.

What I've mainly been working on now is all maintenance work for safety and reliability.

I think I might like working on it more than riding it.

Bike is Diamondback Approach. At first I didn't want to use an "expensive" bike to put a motor on but the parts seem to be higher quality than just a walmart special and it takes the engine like a champ.

She likes going 25 but if I really gas it and believe in myself i can get her up to 30 on a flat.

Kit is a ebay flying horse and has a 44t sprocket.

I think I'll use this thread to plan out my upgrades

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  #2  
Old 08-22-2016, 12:26 PM
2Slow4U 2Slow4U is offline
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Default Re: Redbox Racer post build build thread

MODS

NGK B6HS spark plug
koch #41 chain
turbobuick1 spring chain tensioner
sick bike parts expansion chamber
dual pull brake lever
milled the head down a bit, no idea what the compression is
ebay tachometer
high performance dust
high performance zip ties
air filter that fell off

I’m thinking I want to try to get the max speed up to 40 while not being a dog on hills. Before I start adding/removing stuff I want to get a plan set up so I’m doing everything optimally. I got a rotary drill and a set of carbide bits and I'm reading Two Stroke Tuners guide so I can destroy (improve) the engine

Planned:
exhaust wrap so I can have kids eventually
tempature gauge
new air filter
high performance head
high performance streamers
possibly a cdi if I feel I need it
ultra bright headlight
turn indicators
smaller sprocket probably
Attached Images
File Type: jpg 20160811_191416.jpg (209.3 KB, 43 views)
File Type: jpg 20160816_161917.jpg (111.5 KB, 31 views)
File Type: jpg 20160821_160541.jpg (150.4 KB, 32 views)
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  #3  
Old 08-22-2016, 12:47 PM
2Slow4U 2Slow4U is offline
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Default Re: Redbox Racer post build build thread

When I was putting the engine on I didn't have enough pedal clearance so I had to try and bend the crank. I got it hot with a propane torch and put it under the shed in the back and bent it with with a giant breaker bar. I think I bent it the wrong way the first time so I had to bend it back again.

I messed the thread up and stripped it in the crank so the pedal fell right off when I started pedaling. I ended up going to Lowes and rigging up a "high performance low profile pedal"
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  #4  
Old 08-23-2016, 01:01 AM
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ZipTie ZipTie is offline
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Default Re: Redbox Racer post build build thread

I love the high performance low profile pedal the most, but the high performance zip ties and dust are darn nice upgrades too. Enjoyed your post and your bike.

Yep replace that pesky air filter, pea gravel in the piston can be troublesome.

Zip
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  #5  
Old 08-23-2016, 06:53 AM
2Slow4U 2Slow4U is offline
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Default Re: Redbox Racer post build build thread

Haha thanks

I figure each zip tie adds .5hp. The dust doesn't add speed but does improve mpg by creating increased turbulence around the bike allowing for better airflow..

You're definitely right about the air filter. I was checking ebay and found a carb and air filter for 20 bucks From what I can gather it's a clone of the dellorto SHA. Some things I've read say they are good and other say not so good.

It seems pretty interesting for 20 bucks but at the same time I think I have the stock carb tuned pretty bang on So I'm not sure how much better the new one would be assuming I can get it tuned properly.

So I'll probably find a good filter and call it a day.
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  #6  
Old 08-23-2016, 10:53 PM
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ZipTie ZipTie is offline
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Default Re: Redbox Racer post build build thread

Actually being certified in zip tie technology it only adds .45 horsepower per zip tie, you were close however. For optimum turbulence and air slippage always leave the long end hanging into the wind so it flaps back and forth, thus adding thrust to the slippage.
As far as the carb I prefer the old NT...it's kind of dummy proof once sealed on the intake with a good o ring and besides if my piston moves too fast I get paranoid about parts flying off here and there and everywhere. Slower piston speed plus lots of zip ties improves reliability along with smooth trouble free speed. Your low profile pedal will also help with spin boost.

Zip
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Last edited by ZipTie; 08-24-2016 at 03:22 PM.
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  #7  
Old 08-26-2016, 10:45 PM
Rudz Rudz is offline
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Default Re: Redbox Racer post build build thread

You'll like the SHA clone, the jets are the same as the Italian brother and the filters fit as well. For more top end try a 41 or 40 tooth sprocket. You can still climb hills.
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  #8  
Old 08-29-2016, 12:36 AM
2Slow4U 2Slow4U is offline
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Default Re: Redbox Racer post build build thread

So last Wednesday I busted out the rotary drill and headed into the oven(garage)

NSFW if you work as a machinist.

I thought I had the tuning down but when I took the head off there was a bunch of carbon build up. does that mean it's getting too much gas? From what I understand there shouldn't be any build up if it's running right. I run it at 32:1 on 93 octane now but when I was breaking it in I believe it was at 16:1.

Took the head gasket off, looks like it's leaking oil. Which isn't surprising considering there is a ring smashed into it from the head. I used a torque wrench when I put on the head so I must of used the wrong number or the wrench is jank. I had an extra gasket that I wasn't using because I got the wrong size but i was able to just enlarge the holes. The hole for the piston seems to be a lot bigger though, not sure if that matters.

Instead of going to the tool library and getting the right bits for the rotary drill I ended up trying the carbide bits and the cheap ones that came with it. Even though I knew I shouldn't. The sandpaper bits that came with the drill were way too big and I couldn't get it in there but the carbide bits fit perfectly...

They definitely weren't the right tools for the job haha. I couldn't get it nearly as smooth as I wanted and there is still some paint in there that I couldn't get off. I had the plan of leaving the intake a little rough and the exhaust really smooth, but the best I could get for both was really rough haha.

A couple times the drill shot out and i hit the cylinder wall and it left a small pit.

I could of taken some from the piston skirt but I figured It would be easier to fix one 1 thing at a time if i messed it up. I also completely forgot about the transfer ports.

It was crazy hot outside and I was insane from not sleeping that night and too much coffee. So I know I didn't do as nearly a good enough job as I could have. It was so hot I had sweat dripping off my head and there were puddles on the ground where I was standing. I should of just gotten some sleep and waited for when it was colder but I had been thinking about doing it for a long time.

I also cut off a bunch of metal of the intake and exhaust gaskets. The carbide bits ate those right up.

When I was putting the head back on I ended up wallowing out one of the bolt holes and my heart fell out of one of my ears. I tightened it up as much as I thought I could and went for a ride. it was going fine and I thought it would work until I heard a horrible screeching sound and I started feeling air hit me in the leg. It took a little longer than it should have to realize what it was.
The bolts on the head are are the higher quality replacement ones. I got the idea to try one of the stock ones that I kept where i stripped it and it worked!
I'm still not sure why though, maybe I got the wrong ones? The ones I have on there now are M8-1.25

All in all I'm happy with it. I didn't ride too much because it was hot and I was tired, but the difference seems to be that before it would pull hard up to 25 then die, but now it seems to pull up to 30 before giving up. It also seemed to have gained an extra 500 rpm. Although the tachometer I used broke on me and now it says 1700 when the engine isn't even on.

I'm not sure what was more effective, matching the gaskets or "cleaning" the ports up. But considering how terrible the port work was it was probably the gaskets. These are definitely must do mod. I got better performance gains than I expected.

You can find way more higher quality pictures from the link in my original post.
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File Type: jpg 20160824_095959.jpg (161.1 KB, 13 views)
File Type: jpg 8_29_16 spark plug.jpg (106.2 KB, 12 views)
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  #9  
Old 08-29-2016, 12:59 AM
2Slow4U 2Slow4U is offline
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Default Re: Redbox Racer post build build thread

Some of the things that happened on the first ride after port work:

Gas tank flipped upside down(twice) and killed engine
Got blasted by air on leg from loose head bolt
Tachometer broke
Turned off choke on accident with leg on run and engine died
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  #10  
Old 09-03-2016, 05:59 AM
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ZipTie ZipTie is offline
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Wink Re: Redbox Racer post build build thread

2slow4u, You should just install the gas tank upside down to start and then when it goes haywire it will flip upside down which will then be then on the way you want it, right side up! Gotta outsmart these Chinese parts. Good to hear your port job made it run better I've yet to do port surgery for fear i'll be a bad port surgeon.
Sorry to hear of the tachometer death. Just wondering out loud - How does one break a digital tach? By the blow of a stout Hammer or by melting it with a torch... Curious minds want to know the details.

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