Worksman Newsboy 79cc Predator build

[jimmymc2286]

I bought a Newsboy off Craig's list and just happen to have a new Predator
79cc engine to put on it. This will be my 2nd predator bike. The first one is a vintage looking bike with a sidecar. After riding it I wanted a cruiser with one to be my go-to bike. Compared to the vintage this is just mounting the engine with very little mods to the frame. I will post pictures as I build.
I had to cut the down tube and make a new section. Also made a engine mounting plate. Got them welded in before I took the bike apart. Got the tank started Made it from a piece of 4 inch stainless the muffler shop gave me. It was a tip they took off a truck. Got the ends cut and it is ready to weld up.
Here are some pictures.

 

[PaPa_FoZzY]

the only thing that kept me from buying a worksman frame was being scared the 79cc wouldn't fit. From the looks of it you could have fit a 99cc

 

[PaPa_FoZzY]

never mind, I see that you had to chop the frame...

 

[jimmymc2286]

the only thing that kept me from buying a worksman frame was being scared the 79cc wouldn't fit. From the looks of it you could have fit a 99cc

I think they make a frame a little larger then this one that you wouldn't have to cut. Do to the fact these are not antique or collector bikes I didn't have a problem cuting it. They are very frames and will make a nice bike. I hope.

BTW, The 99cc is the same size as the 79cc on the outside. I just didn't have a 99cc.

 

[jimmymc2286]

I did'nt get much done today. Had real world things needing done. But I did get a little time in the barn.
The jack shaft is done except for the shaft. Will cut the key way, and cut to length in the morning. Tacked the gas tank together and tacked the outlet in. Couldn't find the pipe I was going to make the fill tube out of. Will have to go get one. Then the tank will be ready for the tig.
I have ordered all the parts to get this thing running. I hope they come in this next week. I've not made up my mind what I am going to do for a breather yet. The fenders are chrome, the tank is stainless. I'm thinking maybe something shinny.
More pixs

 

[FLKnifemaker]

Looking good!! I see you are into RC planes. I gave up flying helis last year so I could free up some shop space..............and cut down the space it left in my wallet!!!

 

[jimmymc2286]

Looking good!! I see you are into RC planes. I gave up flying helis last year so I could free up some shop space..............and cut down the space it left in my wallet!!!

I have a lot of helicopters. These bikes are a lot less money. Don't think I am going to stop flying them yet. I'm going to take this bike with me to IRCHA this year to ride around the AMA grounds.

 

[PaPa_FoZzY]

what parts did you use make the jack shaft?

 

[PaPa_FoZzY]

BTW, The 99cc is the same size as the 79cc on the outside. I just didn't have a 99cc.

Did not know that, all hf had was the 79 in my area too

 

[jimmymc2286]

what parts did you use make the jack shaft?

These are the parts I bought. You will need two of each.
http://ombwarehouse.com/5-8-jackshaft-collar.html
http://ombwarehouse.com/Bearing-Hanger.html
http://ombwarehouse.com/5-8-x-1-3-8-Precision-Sealed-Bearing-AZ82051.html
For clearance above the motor mount I used 1 inch strips of the same 3/16 flat stock I made the motor mount out of. The Shaft is 5/8 round stock. Just cut to length and cut the keyway. Take a look at the picture and you will see. I have used this setup on minibikes, and other things with good results.

Harbor Freight stopped handling the 99cc, and only sale the 79cc now. It has a little less power but I don't think you would be unhappy.

 

[PaPa_FoZzY]

Love how your build is coming along. it's going to look nice zooming down the road!

thanks a bunch for the links, this is going to save me over 100 bucks. another dumb question and I'm really not trying to be spoon fed here where did you get the sprockets?

 

[jimmymc2286]

This is where I get my sprockets. They have any size you could want. And sharing knowledge is why we are here.


http://www.usabearingsandbelts.com/18m7/sprockets/35-sprockets.html

 

[FLKnifemaker]

I have a lot of helicopters. These bikes are a lot less money. Don't think I am going to stop flying them yet. I'm going to take this bike with me to IRCHA this year to ride around the AMA grounds.

I sold off the last of my RC stuff to buy my last Harley. I did keep one good Tx and my tried and true 400 electric. It's built from parts and has about a thousand flights on it!! We just had our RC Jet show here in Lakeland 2 weeks ago. Thats' always fun to attend.

 

[jimmymc2286]

I sold off the last of my RC stuff to buy my last Harley. I did keep one good Tx and my tried and true 400 electric. It's built from parts and has about a thousand flights on it!! We just had our RC Jet show here in Lakeland 2 weeks ago. Thats' always fun to attend.

Been there several times. Went there for Sun & Fun airshow several times also.

 

[jimmymc2286]

Got a little more done to the Worksman. Finished up the jackshaft. Got the drive line all finished except the chain roller spring. I didn't have one that will work. Most of the bike is back together getting ready for the test ride and fine tuning.

 

[jimmymc2286]

Just about done. Rode it today. After a 4 mile round trip. Looked everthing over and looks good. The gearing is to high. Ordered a larger sprocket for the jackshaft.
The only things left to do is finish the gas tank, make a clutch cover, paint it, add lights and front brakes.
I can say the little 79cc HF engines are great for these motorbikes. The worksman frames are what they say they are. This one rides very smooth and solid. I don't know what I will build next. But it will have a HF engine on it. I think what I need now is a trike. Maybe a tadpole with a 212cc.

 

[PaPa_FoZzY]

what size sprocket are you getting and what size did you start with?

 

[jimmymc2286]

what size sprocket are you getting and what size did you start with?

The clutch is 11t, driven side jack shaft 28t, #35 chain. Jack shaft drive side 9t, wheel 44t, #41 chain.
I'm going to change the driven side jack shaft to 35t. That should get me up into the rpm range I want. Now the thing will go a lot faster than I want to. With little power till you are zoomming.

 

[jimmymc2286]

The 35t sprocket came in today. Installed it right after morning beverage with my daughter and son-in-law. I also installed a 2250 rpm spring in the clutch. It was grabbing to quick. The gearing is close to where I want it now. I don't have a speedometer or tack on it yet but rode it around 20 miles today. The other 79cc on my vintage build is geared a little lower and cruise is 4500 to 4700. This one is a little lower so should be fine for everyday riding.
The worksman is the best ride I have. Solid, smooth, and comfortable. The little predator engines are about as good as it gets for power, and price. I still have a lot to do to it. It is ride able now and I'll just keep working on it a little at a time. We all know they are never done.