Pedal starting the HF 99cc Predator

[carcrafter22]

Hello, I finally picked up my Felt cruiser bike and started putting the HF 99cc predator in it, I will be doing a belt drive setup using a whizzer rear sheave and possibly a 2 spd setup like WayneZ did on his (haven't decided on that part yet though). Most likely I won't be using a centrifugal clutch or CVT or anything like that, obviously if I want to pedal start it I will have to go manual clutch.

I have the engine centered right now and it seems ok (very well balanced copared to my full suspension Giant VT1 with rack mount predator) but it looks like I can move it over another 2" to make it more comfortable to pedal when needed if I remove the pull rope assembly.

I would assume that as long as I have a manual clutch (using the pulleys and an idler puller to provide tension)that I could pedal up to around 8-10 mph then release the clutch to engage an idler pulley that will tension the engine to jackshaft belt and start the engine.

I only ask because I want to get my engine mount and jackshaft setup right the first time and I can't just put stuff on then go test it till my whizzer sheave gets here and thats gonna be a couple weeks.

Thanks for any help you may be able to give.

Randy

 

[racie35]

2 " isn't enough to worry about is it? you'll miss that pull start eventually

 

[carcrafter22]

I went to the store and picked up some pulleys to mockup the 2 spd and put the pull start back on. The pic below shows the measurements I came up with and it looks pretty wide.

I'd think the lack of pull start would be nice, I'm a motorized bike newb could you tell me why I may miss it in the future?

Worse case scenario I could carry the pull start on the rear cargo rack and bolt it on real quick if needed.

I guess part of it is that I don't like the look of it either, I think it would be much cleaner without it.

http://i1320.photobucket.com/albums/u529/carcrafter22/Motorized Bike/2_zpsc9dcd1d9.png

If its smarter to keep it for the long run then I will.

 

[carcrafter22]

 

[racie35]

will it really get much narrower with it off? still gonna have the flywheel etc.....I guess if you dont feel you'll mis it..go ahead....me, id like to have the option. looks like you have a good start there.....keep us posted

 

[motorhedfred]

If you remove the recoil (pull) starter, AND the cup for it, AND the cooling fins off the flywheel, the engine does get a good bit narrower. You can also take some length off the output shaft but make sure you have enough left for your pulley or pulleys. I assume you're thinking of a jackshaft with 2 driven pulleys, then back to the rear sheave with another pulley on the jackshaft ?

If you have a center or rear stand that gets the back tire off the ground, the lack of recoil starter should never be an issue.

I will say that you're less likely to get hassled by the authorities if you engine looks like it came off a mower or other power equipment, and a pull starter screams lawnmower engine....plus it gives you a handy place for a "49cc" sticker.

MHF

 

[Dan]

Really interesting concept CarCrafter. One of the main things I like about 2 over 4 smokes is the pedal start over the pull start. Just so much easier and it works better. A cranky engine is a PITB but pedal, stomping power seems to really help em cooperate.

The 99cc/79cc's are wide and 2" can be make or brake. Not that you can pedal home like a normal bike with normally spaced pedals. (Done did that a time or 3 and it is not fun)


But think your's is the first I can remember trying a pop starter, 4 stroke. (really, really hard to be the 1st at any thing in our happy little world) Big time looking forward to seeing ya do it.

But like said above, the pull start might come in handy until you get things worked out, me thinks. Always good to have a "plan P" lol.

Post pics! No rush with a work in progress. Building is half the fun and failures are a means to the end. Edison said he had not failed 700 times to make a light bulb. Rather he knew 700 ways how not to make a light bulb.

 

[motorhedfred]

If you don't mind having a rope with a wooden handle in your pocket, in a tool bag or box or just simply looping it around your handlebar, you can still have a rope starter using a pulley the a notch cut into it. Attach it where the recoil mechanism and cooling fins were on the flywheel side.

If it doesn't start on the first pull you'll have to wrap it around again, but it'll work and keep the engine narrow. Just don't rob any banks and use your MB as the get-away vehicle !

MHF

 

[Dan]

Awesome thought Fred! As a kid, every minibike was started like that.

2 funny. If your gonna rob a bank on a bike;
http://www.youtube.com/watch?v=5Db-0dX4ORA&feature=youtu.be

Has to be an ebike or a very stimulated bicyclist. From the thread; http://motorbicycling.com/showthread.php?t=38270

 

[Dan]

Would be a good skit. A bank robber on a MB at the drive-up window.

"Sir, I'm sorry but you have to come inside. We can't serve bicycles at the window"

"IT HAS A MOTOR!"

 

[Nehmo]

... HF 99cc predator...a manual clutch (using the pulleys and an idler puller to provide tension)that I could pedal up to around 8-10 mph then release the clutch to engage...

I have a Predator 79cc Friction Drive & Clutch system.
I can start from 0 speed clutch engaged and reach a rather low speed (no speed gauge, so I don't have numbers) and it starts.
IOW, it starts very easily. I removed the pull-starter. It's extra weight.

 

[carcrafter22]

Excellent info! Thanks How do you like the manual clutch for daily driving?

I called maxtorq today and talked with them about modifying the clutch I have now to add a pulley, sealed bearings and change the engagement rpm. Not sure if I want that or to have to fiddle with a manual clutch setup all the time. I may try both and see how I like it.

 

[Nehmo]

... How do you like the manual clutch for daily driving?

I use the term "daily driving" to mean non-experimental and non-competitive. I'm not sure I'll ever get to the non-experimental stage, but that's the ideal. The real trick to being successful with a small 4-stroke, as I see it, is to solve the clutch problem, and I haven't done that yet. But there is hope. A clutch in this situation doesn't need to be smoothly engaging/disengaging like that of a car. Simply completely in one state or the other and easily toggle-able are the only requirements.

I would veto any centrifugal clutch (CC). You can't lope along (maybe at night) at low rpm engaged, and that's my favorite riding condition. And, of course, a CC isn't bump-start-able.

 

[BigBlue]

If you don't mind having a rope with a wooden handle in your pocket, in a tool bag or box or just simply looping it around your handlebar, you can still have a rope starter using a pulley the a notch cut into it. Attach it where the recoil mechanism and cooling fins were on the flywheel side.

If it doesn't start on the first pull you'll have to wrap it around again, but it'll work and keep the engine narrow. Just don't rob any banks and use your MB as the get-away vehicle !MHF

Rope start - Man that brings back memories to my childhood. My old man had a 50's 3-1/2 B&S that was rope start. He had the Popular Mechanics plans for a suite-case mini bike. It was just as small as today's pocket bike. I always dreamed of him building that bike, but luckily, he won some small change from the Irish Sweepstakes and bought us a Honda Trail 70.

Here's a picture of a rope starter. Might be able to adapt one to the Predator:
http://motorbicycling.com/attachment.php?attachmentid=55022&stc=1&d=1357359273

Good Luck,

Chris
AKA: BigBlue

 

[jbcruisin]

Excellent info! Thanks How do you like the manual clutch for daily driving?

I called maxtorq today and talked with them about modifying the clutch I have now to add a pulley, sealed bearings and change the engagement rpm. Not sure if I want that or to have to fiddle with a manual clutch setup all the time. I may try both and see how I like it.

I have a Max Torque clutch on one of my Whizzers that has a one way bearing so I can pedal start it. it works great.

 

[racie35]

you're gonna go through alot of hassle to have a pull rope and then leave it home when you need it.
who among you.....doubts this?

 

[Nehmo]

... Max Torque clutch on... Whizzers ...a one way bearing ...

What's a one way bearing? This?"edit: Ah I get it now. The freewheel bearing allows the wheels to transfer torque to the engine so it can be pedal started, then the engine cant drive the wheels. But while the engine cant drive the wheels via the freewheel, it can still drive the wheels by connecting it to a centrifugal clutch that has a parallel connection to the wheels. Cant believe it took me this long to wrap my head around this. "

 

[carcrafter22]

I'm gonna try the manual clotch setup and see how I like it. I will decide if I want the pull start on at that point or if I want to carry a rope around with me. I would guess i will be fine with pedal start. I'm going to make a heavy duty kick stand so I can lift the rear wheel off the ground and start the bike in place if I need to.

 

[Nehmo]

I'm gonna try the manual clotch setup and...

I think you're working with the misconception that starting is difficult. (Perhaps you are remembering some experience with a 2-stroke.) It's not. The Predators are very easy to start, and you won't object to having to start off with the peddles and then engage the engine.

 

[Tad Bit Tipsy]

I can hand start the 98cc engine. I have one on a water pump and the rope starter broke quite a while ago. I just turn the flywheel a few time to get gas in the chamber, then I grab hold about 2'oclock once I've brought it to compression... bam, pull down and back in a counterclockwise motion as fast as possible, usually starts first try. Who needs a stinking rope!!!