Just got a bigger engine off ebay. Yamaha kt100. Time to start figuring out how to use this on a bike. Took some side by side pictures to show how silly they look next to each other.
You can get with this... or you can get with that
- Thread starter graydog8josh
- Start date
Based on my experience with that engine, you have some work ahead.
Look for a 3rd bearing support if you plan to run it much. In Karting that can triple the life of a crank bearing set.
Starting is always a challenge. We used handheld electric starters on Karts. The Ultralight Aircraft guys had some recoil starters, but most of them used other means to start the engine cold on the ground. As I understand it, they considered the recoil an "Emergency backup".
The engine is happy at 10,000+ rpm, and has no reduction. You will need at least one jackshaft.
The SMC Vortex 3 disc clutch is the only one I ever had that would last more than a few races :
http://www.kartclutches.com/Products/smc-vortex-black-3-disc-engine-clutch-exploded-view.html#
Please post lots of pictures of your progress. I would really like to see this engine in a bicycle!
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Look for a 3rd bearing support if you plan to run it much. In Karting that can triple the life of a crank bearing set.
Starting is always a challenge. We used handheld electric starters on Karts. The Ultralight Aircraft guys had some recoil starters, but most of them used other means to start the engine cold on the ground. As I understand it, they considered the recoil an "Emergency backup".
The engine is happy at 10,000+ rpm, and has no reduction. You will need at least one jackshaft.
The SMC Vortex 3 disc clutch is the only one I ever had that would last more than a few races :
http://www.kartclutches.com/Products/smc-vortex-black-3-disc-engine-clutch-exploded-view.html#
Please post lots of pictures of your progress. I would really like to see this engine in a bicycle!
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Depends on how fast you want to go.
On a 26" tire, an 11:1 overall ratio puts you at 70 mph & 10,000 rpm
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On a 26" tire, an 11:1 overall ratio puts you at 70 mph & 10,000 rpm
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http://www.kartchain.com/yamaha-kt100-3rd-bearing-support-kit/
looking at this for 3rd bearing support
looking at this for 3rd bearing support
This is going to be a big project and to get it to work right might be a headache. You going to haul around a battery and starter for that motor? The power band is crazy, what wheels you going with?
'This is going to be a big project and to get it to work right might be a headache. You going to haul around a battery and starter for that motor? The power band is crazy, what wheels you going with?'
or I cut just cut a car in half.
I know its going to be a big custom project but I have a shop now and I am working with a mechanic who has all the fabrication tools I need, plasma cutter tig welder, getting a mill and a lathe. torch, hoist.... he's restoring old muscle cars and I have a bay for working on motorcycles and bikes with all my tools too.
I was looking at lynns for a sturdier wheel and was going to run one of the most recommended sprocket adapters.
Its going to be a while for me to piece this build together. Im looking for a better frame to motorize, the bike shop has some electras. I just envision a cantilever frame.
Ooh that new engine looks nice, I can't wait to see progress pics or the finished build! Just don't go crazy with the motor when you get it all setup!
http://www.diygokarts.com/vb/showthread.php?t=17060&page=1
trying to wrap my head around how starting will work.
if I could just use a handheld drill with a rachetting adapter that would be easy
trying to wrap my head around how starting will work.
if I could just use a handheld drill with a rachetting adapter that would be easy
Some of the newer 18 to 24v cordless drills have enough torque to get the job done. I always used a car starter, but even 250 rpm will light the KT100
The over run clutch on the starter is crucial. I have seen sprained wrists & broken fingers from DIY start rigs.
Kart engines need lots of oil. 20:1 or more. 16:1 is a good place to start. I like Castor for the KT, but good synthetic is popular too. Run a little rich to start - plugs are cheaper than cranks.
To save a lot of typing,here is some more info on oil:
http://ffv8.com/2-stroke-oils.html
The over run clutch on the starter is crucial. I have seen sprained wrists & broken fingers from DIY start rigs.
Kart engines need lots of oil. 20:1 or more. 16:1 is a good place to start. I like Castor for the KT, but good synthetic is popular too. Run a little rich to start - plugs are cheaper than cranks.
To save a lot of typing,here is some more info on oil:
http://ffv8.com/2-stroke-oils.html
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Drills do NOT have that function.
That thread you linked to showed using a ratchet adaptor for this job. That might work. We used one-way bearings on the car starters.
An over run clutch or freewheel allows the engine to accelerate when it fires. It will not start if it is trying to spin the starter when it fires. That engine goes from the 250 rpm on the starter to 1000 rpm within a 1/4 revolution when it fires.
Remember the Kt100 shaft turns Clockwise facing the end of the shaft. Starters spin the bolt on the end of the crank to start it. If it fires and the starter is holding it back it can unscrew the bolt or worse.
Never use an impact tool to turn the engine over. If you have a battery drill & want to know if it has enough torque to crank the engine, disconnect the plug wire & try it.
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That thread you linked to showed using a ratchet adaptor for this job. That might work. We used one-way bearings on the car starters.
An over run clutch or freewheel allows the engine to accelerate when it fires. It will not start if it is trying to spin the starter when it fires. That engine goes from the 250 rpm on the starter to 1000 rpm within a 1/4 revolution when it fires.
Remember the Kt100 shaft turns Clockwise facing the end of the shaft. Starters spin the bolt on the end of the crank to start it. If it fires and the starter is holding it back it can unscrew the bolt or worse.
Never use an impact tool to turn the engine over. If you have a battery drill & want to know if it has enough torque to crank the engine, disconnect the plug wire & try it.
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ffv8, you're the man. I'm just trying to piece together what I need to get this build going. Worked a lot of hours over the holiday for a little extra spending money for buying the clutch and trying to get me a worthy frame to chop and get ready for mounting that motor in it. I just want to make sure I don't buy a bunch of stuff I don't really need to get started. ive never tried to start a motor with a drill so I don't know anything about it but I have a Milwaukee 18v I might try to see if it will get it going. ill have to order that rachet attachment
Interesting. It might do the job. I would try it, if it breaks you can return it
I wonder how hard it will be to get a socket on the output side of that tool?
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This is going to be one sick bicycle if it ever gets built.
PICTURES MAN!!!!!
WE ALL WANT PICTURES!!!!
PICTURES MAN!!!!!
WE ALL WANT PICTURES!!!!
