Predator Components

GoldenMotor.com

wayne z

Active Member
Dec 5, 2010
1,743
5
38
louisiana
I bent the cranks for both my preddy builds. I used heat to bend the first one. I came up with a method of "cold bending"on the second one. I bent them while still installed.
IMAG0132.jpg

IMAG0131.jpg

There's a thread about it in general discusson about a month ago.
 

motorhedfred

Member
Jul 31, 2009
421
17
18
United States
Wayne, you're a freakin' genius ! A few hundred years ago, you would have been called a renaissance man. Your practical approach to problem solving with readily availible materials always amazes me.

You probably get a kick out watching the look on the faces of the Lowes staff when they ask you what you're working on. If they're like the ones at my Lowes, they get glassy eyed at about the second sentence.

MHF
 

wayne z

Active Member
Dec 5, 2010
1,743
5
38
louisiana
LOL Thanks MHF. I'm not so much a genius but just someone who don't know the word "can't".
My local hdw store and NAPA know me well now. I'm the guy always digging in the nuts/bolts bins, or looking for some obscure hard to find hardware or parts to use for something entirely different than it was meant for.
 

mesmith

New Member
Jun 30, 2011
47
0
0
United States
I am currently working on the 99cc motor. I have removed the metal piece connected to the throttle on the motor, now do I really need to remove the plastic gear inside of it, or will leaving it there interfere with anything.I figured it may help to keep oil rotating in the the rear of the motor, without doing much of anything else. Does anyone have any input on this matter?
 

wayne z

Active Member
Dec 5, 2010
1,743
5
38
louisiana
I haven't removed anything internaly on mine. I have about 600 hard miles on it, revving it to about 5000rpm a lot.
I actualy left the metal piece(bellcrank) in place, hooked the stock spring up to one of the gas tank stanchions to pull the opposite way to close the throttle, and hooked the throttle cable to the bellcrank at the hole next to the throttle rod on the bellcrank.
Did nothing else to the govenor, and it works perfect.
 

mesmith

New Member
Jun 30, 2011
47
0
0
United States
I also would like to know what rear sprocket to use, my bike is a 26 in., I have an AGK drive, with a 11 tooth clutch, 22 tooth input sprocket, 9 tooth output sprocket. It says to use with a #41 chain, I don't know where to find one ?. and I'n not sure which rear sprocket to use, please help , anyone??? It says my ratio would be 12:44:1
 

mesmith

New Member
Jun 30, 2011
47
0
0
United States
I haven't removed anything internaly on mine. I have about 600 hard miles on it, revving it to about 5000rpm a lot.
I actualy left the metal piece(bellcrank) in place, hooked the stock spring up to one of the gas tank stanchions to pull the opposite way to close the throttle, and hooked the throttle cable to the bellcrank at the hole next to the throttle rod on the bellcrank.
Did nothing else to the govenor, and it works perfect.
Hey Wayne, I seen your bike, and it's a nice one, I really like it. It made me go buy the motor actually so I could have my own. Great work man:)
 

jowens

New Member
Jul 25, 2011
128
0
0
Webster Fl
I also would like to know what rear sprocket to use, my bike is a 26 in., I have an AGK drive, with a 11 tooth clutch, 22 tooth input sprocket, 9 tooth output sprocket. It says to use with a #41 chain, I don't know where to find one ?. and I'n not sure which rear sprocket to use, please help , anyone??? It says my ratio would be 12:44:1
Hey there mesmith,
Ive been planning this build too.....from what Ive researched as far as sprockets are concerned you would need a 56t sprocket to keep a final ratio of 12.44:1 which would give you a cruising speed of 22MPH at 3600 RPM's engine speed.....keep in mind Im quoting you off the max RPM of engine with the governer still in place on the engine.....depending on your situation ie...weight hilly terrain etc...you could drop to a 48t sprocket and get a final ratio of 10.67:1 that gives you a cruising speed of 26 MPH at 3600 RPM's....or drop even lower to a 44t sprocket to give a final ratio of 9.7:1 which cruises you 28.68 MPH at 3600 RPM's.....keep in mind that as you drop your final ratio you are going to lose torque and not pull hills as well as a higher gear ratio....I live in flat florida and only weigh 160lbs so I will be going with the final ratio of 9.7:1.....hope this has helped to answer your question....most people on this forum that Ive seen posting about final ratio recommend a final ratio of 10.5 to 11.5:1 as a healthy final drive ratio.
 

mesmith

New Member
Jun 30, 2011
47
0
0
United States
Hey there mesmith,
Ive been planning this build too.....from what Ive researched as far as sprockets are concerned you would need a 56t sprocket to keep a final ratio of 12.44:1 which would give you a cruising speed of 22MPH at 3600 RPM's engine speed.....keep in mind Im quoting you off the max RPM of engine with the governer still in place on the engine.....depending on your situation ie...weight hilly terrain etc...you could drop to a 48t sprocket and get a final ratio of 10.67:1 that gives you a cruising speed of 26 MPH at 3600 RPM's....or drop even lower to a 44t sprocket to give a final ratio of 9.7:1 which cruises you 28.68 MPH at 3600 RPM's.....keep in mind that as you drop your final ratio you are going to lose torque and not pull hills as well as a higher gear ratio....I live in flat florida and only weigh 160lbs so I will be going with the final ratio of 9.7:1.....hope this has helped to answer your question....most people on this forum that Ive seen posting about final ratio recommend a final ratio of 10.5 to 11.5:1 as a healthy final drive ratio.
Thank You jowens for the information. I live in Illinois and not much as of hills here, so I think the 44t sprocket will be fine for me. I did remove the piece of metal that goes to the governor, so that may give me more rpms and a little more speed.
 

frozenveinz

New Member
Sep 25, 2011
161
0
0
Washington
eBay carries #41 chain, and tractor supply places will too. How many horse do you think this motor can pull? By my calculations, at 3.5 ft lbs max torque at 2500 rpm, that is about 1.6 hp. Assuming 3600 rpm still at 3.5 ft lb, thats 2.4 hp. Not sure about higher rpms, but if the torque is say, 3 ft lb, then thats 2.85 hp @5k rpm. Doesnt seem like all that much, especially with the high gear ratio. :/ Hopefully performance mods will bring that up a lil bit.
 

wayne z

Active Member
Dec 5, 2010
1,743
5
38
louisiana
Wayne, I removed the metal piece that goes inside the motor, is that what controls the plastic governor?
I didn't remove the metal piece going in the block, or anything else except for the factory fricton throttle lever.

I have 2 speeds on my build. Low gear is abour 14:1 and gives about 25 mph at 5000 rpm.
high gear is 9.75:1 and i get about 40 mph at 5000 rpm, and still pulls my 200 lbs up steep hills as long as I have some speed when I hit them to get the engine in it's power band.
 

mesmith

New Member
Jun 30, 2011
47
0
0
United States
eBay carries #41 chain, and tractor supply places will too. How many horse do you think this motor can pull? By my calculations, at 3.5 ft lbs max torque at 2500 rpm, that is about 1.6 hp. Assuming 3600 rpm still at 3.5 ft lb, thats 2.4 hp. Not sure about higher rpms, but if the torque is say, 3 ft lb, then thats 2.85 hp @5k rpm. Doesnt seem like all that much, especially with the high gear ratio. :/ Hopefully performance mods will bring that up a lil bit.
I believe the motor is rated at 31/2 hp.
 

mesmith

New Member
Jun 30, 2011
47
0
0
United States
I didn't remove the metal piece going in the block, or anything else except for the factory fricton throttle lever.

I have 2 speeds on my build. Low gear is abour 14:1 and gives about 25 mph at 5000 rpm.
high gear is 9.75:1 and i get about 40 mph at 5000 rpm, and still pulls my 200 lbs up steep hills as long as I have some speed when I hit them to get the engine in it's power band.
40 mph is fas t enough for me...my 2 stroke can hit 43, at least that is what my speedo says.
 

jowens

New Member
Jul 25, 2011
128
0
0
Webster Fl
Well with the governer not limiting the rev's to 3600....if you use the 9.7:1 ratio at 5000 RPM's you should get 39.83 MPH so that should get you to where you wanna be.....of course I wouldnt suggest running it at 5000 all the time.....not that I know a bunch about these engines but Im guessing the swwet spot to run the Predator is around 4000 to 4500 RPM....this gives you a speed of 31.86 to 35.85 MPH with that 44t sprocket.
 

arand18

New Member
Jan 13, 2012
17
0
0
Brisbane
Hey guys I am planning on my predator build and am going to buy all the stuff very soon. I made a list of all the components I think I need. Can anyone tell me if there is anything I could cut or anything I missed? I'm going for lowest cost possible.

Also I will be putting my MTB fork on which has very strong v brake. Thats why no brakes on list.

And what drive ratio should I go for? I would like the motor to cruise without being wound out at 30, but still pull hills well (is this impossible?) as I've got some big ones, not long, but VERY steep. Walking down I think you would roll all the way down if you trip, about .2-.3 miles each.
With the JS at 11/22, would output 9/48 be okay for my purposes? This gives me 29 mph at 4k rpm. Governor removed of course. Is this an okay engine speed? Max at 6k indicates 43.5 (I don't plan on going that fast!). Will it pull hills, or is that too high a ratio at 10.67?
My current chinagirl bike and I weigh a tad under 200, with a 41T I have to heavy pedal assist up these things.

------------------------------------------
WM HUFFY CRANBROOK: 80

HF 99CC PREDATOR: 110

AGK Jackshaft: 135
AGK CLUTCH: 40
AGK COVER: 45
AGK MOUNT PLATE:25
AGK SHIPPING: 13
AGK TOTAL:::::::::::::: 257

DAX THROTTLE: 13
DAX FUEL VALVE: 4
DAX CHAIN: 12
DAX FUEL LINE: 2
DAX SHIPPING: 9
DAX TOTAL:::::::::::::: 40

PB 2.5 TANK: 25
PB SPR ADAPTER: 60
PB KICKSTAND: 25
PB SHIPPING: 15
PB TOTAL::::::::::::::: 136

TOTAL:::::::::::::::::::613

-----------------------------------------

.trk.trk.trk.trk
I am looking at making a motorised bike with a 99cc preditor engine, where did you get all those perts from as I tried to find them and I couldn't
 

wayne z

Active Member
Dec 5, 2010
1,743
5
38
louisiana
40 mph is fas t enough for me...my 2 stroke can hit 43, at least that is what my speedo says.
If yer speedo is one of the cheap analog ones like mine, in my avitar above, you can't trust what it reads. Mine sez 55 when I'm going 40.