Using a 301cc Predator engine from Harbor Freight

[PyroPanda666]

Hello all, I am new to the group and was looking for info into some issues I’m thinking of before attempting to dive into this build I would like to do. I am mechanically aware and can also weld and fabricate if need be. Most of the links landed me back in this group in a few spots. So I decided to join and get a little more acquainted figuring this would be my most reliable space for solid information to what I’m doing.

That being said, my engine of choice is the 301cc predator from harbor freight. 8 horse power and 14.9 torque out the box. 3600 max speed rpm.

If I put a single sprocket on a mountain bikes axle, will the standard chain hold up running just a chain from the rear sprocket to a sprocket I put on the engines axle? Can a mountain bikes rear axle handle the pressure from the torque? What teeth count should I look for as for both sprockets? Can a mountain bikes frame handle the physical wear and tear of the bumps and speed? Suspension can be a small luxury but id like to see essentially if I can make it more “road worthy” in terms of a gas bicycle that wants to be a fake motorcycle. I’ve worked with cars and motorcycles and engines for both. Engines are mostly engines across the board. But the physics and the demand of strain on the parts for a bicycle are not the same.

In advance, any and all advice is welcome, many thanks!

 

[Gordy]

8hp is a lot on a bicycle, and the 301cc is a very big engine. I suggest you go for a predator 213 on a cruiser bike. That's good enough for maybe 60mph stock with the right gearing (trust me, even 40mph is scary on a bicycle). The stock bike chain won't hold up. With what you're looking at doing you need a lot of money to make safely.

 

[PyroPanda666]

8hp is a lot on a bicycle, and the 301cc is a very big engine. I suggest you go for a predator 213 on a cruiser bike. That's good enough for maybe 60mph stock with the right gearing (trust me, even 40mph is scary on a bicycle). The stock bike chain won't hold up. With what you're looking at doing you need a lot of money to make safely.

Are there upgrades to the 212 that could be done to squeeze some more out of it? My first motorcycle was a 1950 Honda 550cc and I had to fix it up from its previous owner. First time I had it together and running, before getting the muffler that I ordered I had it on the road at 100. Safety does matter but more so only with what can handle what for me. I did want to plan to be able to go on the high way with it, which I know if I want to do safely I’m adding a little battery and lights and all. But my concern with getting to highway speeds is the wheels handling the pressure. From what I’ve been told the rims I was pointed to were like 1000 each. So that definitely isn’t the route for me on that end.

Between what mods could the 212 take, would you mind entertaining me on the not most expensive route for the 301cc route?

 

[Gordy]

Are there upgrades to the 212 that could be done to squeeze some more out of it? My first motorcycle was a 1950 Honda 550cc and I had to fix it up from its previous owner. First time I had it together and running, before getting the muffler that I ordered I had it on the road at 100. Safety does matter but more so only with what can handle what for me. I did want to plan to be able to go on the high way with it, which I know if I want to do safely I’m adding a little battery and lights and all. But my concern with getting to highway speeds is the wheels handling the pressure. From what I’ve been told the rims I was pointed to were like 1000 each. So that definitely isn’t the route for me on that end.

Between what mods could the 212 take, would you mind entertaining me on the not most expensive route for the 301cc route?

There are tons of high performance parts for a 212. People have built them up to 20+ HP. But if you did decide to go with the 301 you would want a heavy built frame, probably a worksman, and a good set of wheels. Those aren't cheap frames. I've never priced them as I have no intention of buying one, just look up worksman cycles. After that you would need a 40 series torque converter. For a good one that's around 200 dollars. After that you will have to s of time into fabrication and just fine tuning the setup.

 

[PyroPanda666]

There are tons of high performance parts for a 212. People have built them up to 20+ HP. But if you did decide to go with the 301 you would want a heavy built frame, probably a worksman, and a good set of wheels. Those aren't cheap frames. I've never priced them as I have no intention of buying one, just look up worksman cycles. After that you would need a 40 series torque converter. For a good one that's around 200 dollars. After that you will have to s of time into fabrication and just fine tuning the setup.

Is a torque converter needed for the 212 set up? I appreciate you entertaining the other part of the question. Since I wasn’t buying a kit off amazing, I’d still be buying a rear sprocket and some things. So what would I be looking at for those?

 

[DAMIEN1307]

But if you did decide to go with the 301 you would want a heavy built frame, probably a worksman, and a good set of wheels.

Very true this is Gordy, anything less would be quite dangerous going with a set-up like this.

Not to mention that what he wants to do with this bike in New Jersey is pretty much illegal as all hell, plus he wants to have it on the expressways/highways of New Jersey???...lol.

Motorized Bicycles​

In the State of New Jersey, a motorized bicycle or moped is defined as a bicycle that also has the following characteristics:

• Has a motor that is less than 50 ccs (if powered by gas), and produces 1.5 brake horsepower or less.
• Can’t propel itself faster than 25 mph on level ground.

It’s important to note that motor driven tricycles are not legal to operate on public roadways.

 

[PyroPanda666]

Very true this is Gordy, anything less would be quite dangerous going with a set-up like this.

Not to mention that what he wants to do with this bike in New Jersey is pretty much illegal as all hell, plus he wants to have it on the expressways/highways of New Jersey???...lol.

Motorized Bicycles​

In the State of New Jersey, a motorized bicycle or moped is defined as a bicycle that also has the following characteristics:

• Has a motor that is less than 50 ccs (if powered by gas), and produces 1.5 brake horsepower or less.
• Can’t propel itself faster than 25 mph on level ground.

It’s important to note that motor driven tricycles are not legal to operate on public roadways.

That’s for slow speed, from what I read it would be held to standard motorcycle requirements and regulations. I can avoid highways, it can be a nice pipe dream for a gas bicycle. But I also don’t entirely mind being illegal. It’s only illegal if your caught.

 

[michael whiteman]

Welcome to the forum. You've come to the right place. There are a lot of very knowledgable people here that have spent too much money doing it the wrong way. We'll all help guide you through our mistakes.

Kenny, the owner, of Buchannan Spoke and Rim Inc. builds motorcycle wheels, but will also cut you a set of heavy gauge spokes for your rims like he did for me. So you have another option other than the mag wheels so many of us run. The inportant thing is to get disc brakes on them if at all possible.

Personally I would start with a 212 Predator. There are a ton of hi performance parts available and all the supporting information you'll ever need. Plus it's lighter and not as large which will make mounting it a lot easier. You'll have more than enough HP to get in trouble with.

The first thing, and I'mn sure you have already decided this, is to remove the governor and install the aluminum billet flywheel so you won't rip your calf open when the stock one disintergrates. I'm in the process of doing mine today on a 79cc. After that exhaust, carb valve springs and head work until you run out of money.

Like GW stated, you might want a CVT but you'll need to spend some time calculating gear ratios first. Here's a link to the best and easiest chart to use.

Motor and Gear Ratio Guide and Calculator for Vehicles with a Jackshaft - ElectricScooterParts.com

Electric scooter with jackshaft motor and gear ratio guide with gear ratio calculator.

electricscooterparts.com

Just for grins if you think of runing a single chain from the engine to the wheel simply put 10 and10 in the boxes for Jackshaft Input and Output. With the CVT you'll need to calculate it twice. First with a 3:1 ratio for starting out and again with a 1:1 ratio for when you really flying.

All of the sprokets for the rear wheel are mostly for a #415 chain that comes in all the kits. The go kart people use a heavier chain but their sprokets attach to a live axle with a different hub that doesn't work on bikes. Personally I would build your bike with the 415 chain and upgrade it later if you have any problems. The small sproket that fits the 415 chain can only be found at Stanton Inc. He has a lot to choose from. He has ground them down to be thinner to fit the chain. You could also do this yourself it you have a lathe or drill press. The folowing post will show a couple of chain charts so you can compare. The #41 chain is the only one that has the same pitch and roller diameter as the #415, so it will run on any rear wheel sprocket with increased sile slop. Another interesting thing I just read.................the #35 does not have an inner pin, which is desirable. I'm running one of those.

I hate rag joints. Just my personal opinion, but I do understand the need for them and a lot of us use them. I would recommend bolting the rear sprocket to the disc brake flange. Second best is the hub adapter that clamps on the center of the hub. You definitely want to pin this permanently and not rely solely on the two bolts to hold it.

I hope this, along with what my friends here have to say, will get you started down the right path for a successful build. Just remember, the only dumb question is the one you didn't ask. Best wishes.

 

[Gordy]

If you're gonna register it as a motorcycle anyways, why not buy an MB200 from gopowersports.com and get it titled and registered as a motorcycle?

 

[DAMIEN1307]

It’s only illegal if your caught.

You live smack dab in the middle of the Northeast Corridor in the most intense police traffic enforcement area of that entire Eastern Corridor...lol...lol,

As a retired East Coast area Police Lieutenant, I rate your chances of NOT getting caught somewhere between slim to none...lol...lol.