79cc Sportsman Flyer build

Nightster

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Tom from Rubicon

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When I used to live in NE Illinois one early fall after harvest 2003. My across the road neighbor, hired me tp chisel plow 400 acres. Also called subsurface plowing. Top tillage by comparison on typical acreage yields 30% to 40% less yield'
So fueled up and plowing with Steve's 4455 JD 4WD I got into a bit of high ground plow down. Field mice squirting out of the ground just ahead of the tractor, and yotes in front of my wheels catching them.
That was as close I have ever been to a yote. I never lost anything. but on occasion, tracks were right to the door.
Never did get anything done on the Flyer today. But in my head the plan is made. It is for me to execute.
 
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Tom from Rubicon

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Well nothing done today. Mona is returning from a mini vacation. Reverting to domestication mode.
For you married fellow's you know what the Stink Eye can do. Doesn't bother me, but I know, you know.
Still for domestic tranquility I do. Same thing I said when the Judge said "do you take her".

I would love for someone to tell me why a 79cc Predator needs a rocker cover vent, and how you have successfully managed the venting. Can one direct the rocker cover vent to the crankcase?
This may be nothing. But this is to me a unresolved questions. It could be my first engine was flawed. Happy Juneteenth.
Tom
 

Nightster

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Well nothing done today. Mona is returning from a mini vacation. Reverting to domestication mode.
For you married fellow's you know what the Stink Eye can do. Doesn't bother me, but I know, you know.
Still for domestic tranquility I do. Same thing I said when the Judge said "do you take her".

I would love for someone to tell me why a 79cc Predator needs a rocker cover vent, and how you have successfully managed the venting. Can one direct the rocker cover vent to the crankcase?
This may be nothing. But this is to me a unresolved questions. It could be my first engine was flawed. Happy Juneteenth.
Tom
Lol, stink eye

Happy Juneteenth to you and Mona.
 

Tom from Rubicon

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Alright, Sweetie came home to a well ordered house and lawn and potted flowers under control.

I had no idea how the S E metaphor could bring back such painful memories for any who have been gazed on so.

The dear sweet child, that is Mona. She has want's and wishes, but is very unjudgmental. Now you know why we are a unit.
Mona, saw my enthusiasm for this motor sport as a positive thing
 
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xXNightRiderXx

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The rocker arm cover is your pcv valve. It releases the pressure buildup in the crankcase to keep the oil from gathering on the crankshaft. It also allows the piston to move freely, rather than have all that pressure pushing against the piston on each downstroke. This improves fuel economy and throttle response. I remember the difference it made when I swapped from the ventless CNC short cover I had on my bike back to the stock cover. I no longer have oil coming out of the case, I had immediate gains in acceleration and throttle response, and it sounds healthier. But now, I have old gas and need to deal with that because my engine won't run without the choke.
 

indian22

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Though I prefer the vintage look of a vertical mount motor I've come to a point of really liking the slant profile motors in frames which can't readily accommodate a vertical engine position without complex frame alterations. Tom's comment on using these 4 stroke motors in the factory designed mounting position allows the use of a broad range of bike frames and can really lower the cost of a basic build. As mentioned easy motor adjustability is a big factor to consider when buying or fabricating the motor mounts. Even if you are dead nuts certain that your alignment is perfect it's comforting to allow yourself a bit of wiggle room! Though I don't use the motor on a plate style mounts they work, are inexpensive, for the most part, and relatively easy to install properly. I'd give them a nod for these reasons.
My first build was straight up CG kit bike on a cruiser frame and after a few rides I started discarding/modifying parts used from the kit until nothing remained but the little motor and frame tubes. Really good experience, but took some time (this forum didn't exist at the time) and all parts had to be custom machined because they did'nt yet exist. Things have really changed and in motor bike building mostly for the better.

Rick C.
 

Tom from Rubicon

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Looked at the Johnson engine sellers inventory. $hit load of Maytag engines.
Couple big shows near me with hit n miss engines Fairbanks Morse galore. Some BIG!
Show Information (thresheree.com)
And in Northern Illinios is the Northern Illinois Steam Power Club show home (threshingbee.org)
I keep telling myself that I need to get my 53 Ford Jubilee show ready. Not. Only thing it needs is a functioning TPH.
Long story -short. 53 Ford, two styles of hydraulic pump. Neither one was long lived, or they almost never failed.
Mine must have been a Monday build. Through a Ford Forum, a fella in Va. builds industrial hydraulic replacements.
I bought one ten years ago. Still in the box. Used to sorta have an excuse.

Rethinking the PCV thang with NightRiders input. Still plumbing to the catch can, but instead having a sintered brass exhaust port, I am plumbing the catch can exhaust to the airfilter. Photos to follow soon.

Tom
 

xXNightRiderXx

Active Member
Jan 12, 2017
469
113
43
Boise
Looked at the Johnson engine sellers inventory. $hit load of Maytag engines.
Couple big shows near me with hit n miss engines Fairbanks Morse galore. Some BIG!
Show Information (thresheree.com)
And in Northern Illinios is the Northern Illinois Steam Power Club show home (threshingbee.org)
I keep telling myself that I need to get my 53 Ford Jubilee show ready. Not. Only thing it needs is a functioning TPH.
Long story -short. 53 Ford, two styles of hydraulic pump. Neither one was long lived, or they almost never failed.
Mine must have been a Monday build. Through a Ford Forum, a fella in Va. builds industrial hydraulic replacements.
I bought one ten years ago. Still in the box. Used to sorta have an excuse.

Rethinking the PCV thang with NightRiders input. Still plumbing to the catch can, but instead having a sintered brass exhaust port, I am plumbing the catch can exhaust to the airfilter. Photos to follow soon.

Tom
I'd be interested in how you pull this off. The stock configuration has the pcv doubling almost as an egr, but instead of exhaust gas, it's blowby gas. Imo, there's no real benefit to that in these small engines. In a larger, multicylinder engine, perhaps there is a benefit, because there's a lot more blowby that happens there. I still need to get a hose and filter into my cover though, it's just open to the dusty air here. Just yesterday, we had high winds kick up a lot of dust.

Oh, one more thing: does anyone know of any frames that will handle a 212 if it put out 7hp stock? I have an electric start 196cc motor sitting in my shed waiting for such a frame. I've been thinking that I want to use my Schwinn occ stingray for this build, but I just don't have the equipment or knowledge to do that just yet.
 

Tom from Rubicon

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Rainy day, perfect time to plumb the catch can vent to the high flow air cleaner. First operation drill the sheet metal endcap of the air cleaner with a letter Y drill. First I had to modify a lathe arbor to fit the clamping section of the air filter.
Done and drilled. The 3/16 barb 1/8NPT male goes in. To hold it place I needed what would be a 1/8NPT nut.
Never seen one. Plan B, could have used a 1/8NPT coupling but I wanted wrench to draw the assembly together.
1/8 NPT hex end cap drilled thru and pipe tapped a bit deeper threaded together with hydraulic grade pipe dope.
Installed a 3/16 hose barb fitting, replacing the atmospheric catch can vent. Clipped hose to fit. Clamps tomorrow.
Edit. Before remounting the air filter I cut to fit 3/4" thick green filter foam, right where the carb mouth enters the filter.
If I don't like it I will pull it.


Tom
 

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Tom from Rubicon

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Been still thinking of venting the crankcase, in similar fashion. On this forum there is no empirical data or experience.
Returning the blow by oil from the catch can to the crankcase is worth looking at.
A one way Lee Loc valve might work. Check Valves - The Lee Company

In a few Sportsman Flyer Bonneville photos there were fleeting views of such a system. Pat never got back to me.
No big deal. He has a heavy work load, and I will sleuth it out. The lube in my Flyer is the same I run in my R80/7.
15-40. Air cooled engines like it.
Tom