Sportsman Flyer Build

[Deleted member 25783]

Exhaust is completed, instead of using Pat's well engineered exhaust system. I made my own exhaust system, two exhaust clamps of 6061 T6 aluminum the finned one at the engine and one to clamp the exhaust pipe to the B&S 3/4NPT muffler intake side. Also two strap clamps, one to hold the exhaust pipe to the frame and a larger one to clamp the muffler.. The strap clamps are of HRPO steel1mm steel thick] that I formed and drilled for mounting screws. The strap clamps got a black oxide finish, then hot waxed for corrosion resistance. Photo captures it all.

 

[Deleted member 25783]

Today was supposed to be the day, turned out it was not. Engine compression is unacceptably low. I had the right side case off to remove the governor assembly and the camshaft comes out to remove it, The tappet rods drop when doing so. That is no biggie, reassembly requires getting the tappet rods back into the rocker arms and resting on their cams under tension. Really simple stuff, but something is not right. I have all sorts of patience but 2018 does not. So I ordered another engine from HF and will install it with out mods. Then with time and beer will sort out that which I chose not to do at this time.

 

[Will'smotobikes19]

Today was supposed to be the day, turned out it was not. Engine compression is unacceptably low. I had the right side case off to remove the governor assembly and the camshaft comes out to remove it, The tappet rods drop when doing so. That is no biggie, reassembly requires getting the tappet rods back into the rocker arms and resting on their cams under tension. Really simple stuff, but something is not right. I have all sorts of patience but 2018 does not. So I ordered another engine from HF and will install it with out mods. Then with time and beer will sort out that which I chose not to do at this time.

I may be having similar problems with mine I cleaned the carb and put the stock spark plug back on but it still won't start Maybe you should try using a GX120 they are good quality Japanese engines. I was thinking of using one. They make billet rods and flywheels for them too and more power than the 79cc. They are more expensive though.

 

[Deleted member 25783]

I may be having similar problems with mine I cleaned the carb and put the stock spark plug back on but it still won't start Maybe you should try using a GX120 they are good quality Japanese engines. I was thinking of using one. They make billet rods and flywheels for them too and more power than the 79cc. They are more expensive though.

Will, tempt me not! I got a slight case of more poweritis now.

 

[Deleted member 25783]

Current engine to be pulled, hopefully with Sportsman Flyer engine mount, and diagnose WT# is not right. Surely my fault. Until it is out of the frame. To be continued.

 

[Will'smotobikes19]

Found out I have no spark magneto must have went bad.

 

[Deleted member 25783]

VNB replied
I know compression is way too low???this is a couple of weeks late, but what makes you think the engines

FYI, there is a compression release on the cam (for easier pull starting)!!! The compression will dramatically increase after the engine fires up

Hi Norm, you are not late. I am. As earlier posted, compression seemed to me not the stated 8.5-1. My Huasheng has more compression. Any way I’m yanking away and the recoil takes a s**t. Great!

Order new engine from Harbor Freight. That arrived last Saturday. Pull it out of the box and give it a yank…. It is a wimp too! So it gets wrapped up and back in the box.

And then today, I get a post from VMB about compression release in the highlited above. On a little bitty 3hp? The 8hp Tecumseh doesn’t on my snow thrower. If that baby doesn’t start on the first pull it is aerobic exercise time.

Back to be beginning. Engine came out of the frame on it’s mount. The frame mount remains with the frame. Genius!

I put the engine back into the frame mount easy as pie.

So I’m thinking, instead of screwing around repairing the recoil start just going with rope pull. That option is there to use, and the bike has the cute little tool storage box to store the rope.

 

[Deleted member 25783]

Well today I gave the recoil start a fair chance at reassembly. Did not go well. After a great day as a Tool and Die Maker, I come home have a few beers and head to the shop with another beer to keep me hydrated. (There were more). I would like to see how it is done at the factory as it was like no spring recoil I have repaired before. Taking up valuable time in my shop. So knowing Pat has done builds (not SF80) but similar with open fly wheel. I did it. Plastic fan had to come off, so I did it the easy way. Copper chisel around cutting right around the pull start hub fan so as not to damage the cast iron fly wheel took two passes around with that copper chisel. I like it.

 

[Deleted member 25783]

Long day Friday ,Saturday, and Sunday . After my brain fart about compression, I went into high gear to reassemble the drive train, complete. Re-attach fuel system. Finally make a reliable throttle system. PZ19 Mikuni on middle needle notch


Put a BF Goodrich inner tube in front wheel, Rear went flat first and got a Goodrich too. Schwinn inner tube had a weak spot Read Chinese junk. No offence to my Chinese friends.
Went through the whole bike, making sure all fasteners were torqued. Sturmey Archer front brake adjusted, and rear Shimano 110 bearings running free when axel nuts drawn up.
(Mind you there is no operating manual for any motorized bicycle. I may over time develop one.)
That said, it was time. Rolled the Flyer 80 over to the machine shed and pumped in a ½ gallon of 90 proof no ethanol, opened the cock, turned on the ignition switch, set the choke, and gave the engine a spin. Then I had to figure out which position is on the ignition switch.
Now I know. Carb needle is in middle notch, used the longer Champion plug gaped at .030.
The first 10 minutes and more I wrestled with attaining an idle that did not engage the Bully clutch, and during run in it was still not right. But over the next hour, as the engine started to break in, an engine idle RPM that did not engage the Bully clutch or die is starting to be reliable. Over all performance is with an hour on the machine already exceeding my expectations
Dry pedaling the drive system was noisy. Under engine load the only sound is engine exhaust.
So far my only trouble is the Brooks model 190. Their best biggest model.
Stock finish is slippery, the ride suspension superb.
The Felt springer fork function exceeded my expectations.

 

[Deleted member 25783]

Does this forum have a PZ19 setup guide? Lower idle would be good too as it seems the Bully clutch sometimes engages at idle. Otherwise this bike exceeds my expectations for excellence. Pat Dolan is the man.