Well Pete, so far your prognostication ain't holding. I think the workshop elves have nicked them.
Tom
Tom
79cc Sportsman Flyer build
- Thread starter Tom from Rubicon
- Start date
3/4" flex-hone arrived by mail today.
Chucked the Flex -Hone shank, in my cheap cordless drill, and gave the 79cc predator engine ports a go.
My drill RPM must have been a bit high or my elbow action slow, cross hatch was not the ideal 45 degrees. 30wt for lube.
Washed the head again with Dawn dish soap with tooth brush. Rinsed in super hot tap water, hand dried as best I can.
Then into a 200F oven for a hour or two to cook out any lingering moisture.
45 degree cross hatch it has not, more like 30. But uniformity was the end game, and uniform there is.
Time to lace up the engine. A static run up has been considered. No sense mounting it in the Flyer un proven.
Lord knows I have stock engine parts up the bazooty
Don't expect immediate progress though. Sunday is quality time with Miss Daisey.
Foot note;
Elves have absconded with six 6x1x30mm flange head bolts. I will seek them no further
Tom
Chucked the Flex -Hone shank, in my cheap cordless drill, and gave the 79cc predator engine ports a go.
My drill RPM must have been a bit high or my elbow action slow, cross hatch was not the ideal 45 degrees. 30wt for lube.
Washed the head again with Dawn dish soap with tooth brush. Rinsed in super hot tap water, hand dried as best I can.
Then into a 200F oven for a hour or two to cook out any lingering moisture.
45 degree cross hatch it has not, more like 30. But uniformity was the end game, and uniform there is.
Time to lace up the engine. A static run up has been considered. No sense mounting it in the Flyer un proven.
Lord knows I have stock engine parts up the bazooty
Don't expect immediate progress though. Sunday is quality time with Miss Daisey.
Foot note;
Elves have absconded with six 6x1x30mm flange head bolts. I will seek them no further
Tom
After a Sunday drive with Miss Mona.
I remember when I hated Sunday drivers.
Back in the shop, thinking I will get the top end of the engine laced up. Details derailed me.
I should have finished fastening the stock Predator engine mount to the engine block and bolting the engine mount to a poplar board. That board I will / did clamp in a bench vise. This is all just to create a secure system for the rest of the engine fastener torqueing. I just didn't like the AGK way of holding an engine being torqued.
If you recall, instead of as AGK does, machining the portions of the valve guides protruding into the valve guide pockets.
I chose to press the valve guides back flush with the valve pockets and then having to mill off some of the intake valve guide to fully seat the intake valve guide seal to the valve spring seats.
I never checked when I pressed the valve guides in, to see if any metal deformation had occurred. It had, but it was only on the exhaust valve guide bore had metal deformation, like crushing and collapse occurred. May be a .015" per side.
Valve stem would not go in.
The solution was a conical H.S. burr driven with a electric hand drill, gently.
The resulting chamfer, allows free valve stem passage. Lesson learned. Press valve guides with copper drifts.
Both valve stems now are free in their guides. Lacing / assembling, now unencumbered.
Wanting to get the Sportsman Flyer to the. Classic Car Show - May 15, 2021 (hartfordchamber.org)
Told Pat, if he would work with me I would be his Mid West ambassador. That's the plan.
Sadly I have no business cards for Sportsman Flyer.
4/26 will be a very productive day. Eskers look out.
Tom
I remember when I hated Sunday drivers.
Back in the shop, thinking I will get the top end of the engine laced up. Details derailed me.
I should have finished fastening the stock Predator engine mount to the engine block and bolting the engine mount to a poplar board. That board I will / did clamp in a bench vise. This is all just to create a secure system for the rest of the engine fastener torqueing. I just didn't like the AGK way of holding an engine being torqued.
If you recall, instead of as AGK does, machining the portions of the valve guides protruding into the valve guide pockets.
I chose to press the valve guides back flush with the valve pockets and then having to mill off some of the intake valve guide to fully seat the intake valve guide seal to the valve spring seats.
I never checked when I pressed the valve guides in, to see if any metal deformation had occurred. It had, but it was only on the exhaust valve guide bore had metal deformation, like crushing and collapse occurred. May be a .015" per side.
Valve stem would not go in.
The solution was a conical H.S. burr driven with a electric hand drill, gently.
The resulting chamfer, allows free valve stem passage. Lesson learned. Press valve guides with copper drifts.
Both valve stems now are free in their guides. Lacing / assembling, now unencumbered.
Wanting to get the Sportsman Flyer to the. Classic Car Show - May 15, 2021 (hartfordchamber.org)
Told Pat, if he would work with me I would be his Mid West ambassador. That's the plan.
Sadly I have no business cards for Sportsman Flyer.
4/26 will be a very productive day. Eskers look out.
Tom
I screwed up. No pitchers.
That said, head bolts torqued 20 fp , one bolt would not torque to spec. of 22. same happened with the rocker arm studs. Intake set at torque, exhaust to the same load would not stop. my choice was when to stop leave it before the threads shear and strip. Aluminum is a PITA. actually cast iron needs the same consideration.
Adjusting valve lash is Tuesdays fun fun.
Here is my question. Break the engine in on the bench or run it like you stole it.
The engine will have a break in period regardless. My thought is lawn equipment engines go WOT from the get go.
Thoughts?
Tom
That said, head bolts torqued 20 fp , one bolt would not torque to spec. of 22. same happened with the rocker arm studs. Intake set at torque, exhaust to the same load would not stop. my choice was when to stop leave it before the threads shear and strip. Aluminum is a PITA. actually cast iron needs the same consideration.
Adjusting valve lash is Tuesdays fun fun.
Here is my question. Break the engine in on the bench or run it like you stole it.
The engine will have a break in period regardless. My thought is lawn equipment engines go WOT from the get go.
Thoughts?
Tom
Break her in hard on the bike to achieve a superior ring seal. Use regular oil with zinc additive. Change oil after first 10 miles. Switch to synthetic 10w-30 on 2nd or 3rd oil change. Will last a long time and get stronger as you ride it more. Can’t wait to hear about how it runs, you’ve got some serious upgrades in that little motor.
Zink additive oils? My favorite Pennzoil has Moly in it. What flavor do you recommend Tony?
You Cali guys may access juice us mid west folks don't have I'm thinking.
So run it like I stole it. Works for me. Predators are industrial engines. Fuel them up and WOT. Thanks Tony.
Now i know why they sell those scewdriver looking things for pushing the valve spring retainers. Doing two manually, one was fun, second was pain. Those 18# springs tested my mettle.
You Cali guys may access juice us mid west folks don't have I'm thinking.
So run it like I stole it. Works for me. Predators are industrial engines. Fuel them up and WOT. Thanks Tony.
Now i know why they sell those scewdriver looking things for pushing the valve spring retainers. Doing two manually, one was fun, second was pain. Those 18# springs tested my mettle.
"Break her in hard on the bike to achieve a superior ring seal. Use regular oil with zinc additive. Change oil after first 10 miles. Switch to synthetic 10w-30 on 2nd or 3rd oil change. Will last a long time and get stronger as you ride it more. Can’t wait to hear about how it runs, you’ve got some serious upgrades in that little motor."
Everything you say correlates with my experience Tony, about break in of these 79cc engines. Over time they run freer.
Will be fun to compare performance.
Tom
Everything you say correlates with my experience Tony, about break in of these 79cc engines. Over time they run freer.
Will be fun to compare performance.
Tom
Searching for a quart of break in oil.
In the mean time, valve lash is set cold as per AGK .004" and in my case 60F. A 79cc head is so confined I had to bend the tips of the .006 and .004 feeler guage tips to be able to attain a sensitive feel. Rocker cover is on.
Next trick is fitting the blower housing and see if the recoil start works correctly.
It could be so simple as pulling the flywheel and lapping it (key note word) "into" the crankshaft taper. The magneto pick up is not centered on the magnet field. Any thoughts?
In the mean time, valve lash is set cold as per AGK .004" and in my case 60F. A 79cc head is so confined I had to bend the tips of the .006 and .004 feeler guage tips to be able to attain a sensitive feel. Rocker cover is on.
Next trick is fitting the blower housing and see if the recoil start works correctly.
It could be so simple as pulling the flywheel and lapping it (key note word) "into" the crankshaft taper. The magneto pick up is not centered on the magnet field. Any thoughts?
Attachments
Blower housing is now on and some of the tin bits. Started with the recoil pull start attached. A few pulls of the starter rope were less than ideal. So off it came, and so exposed the rope start hub, just barely. But enough to wind a full pull start rope.
Time to swap engines with the one currently powering the Sportsman Flyer.
Photo of the ready to load 79cc hot rodded engine.
Time to swap engines with the one currently powering the Sportsman Flyer.
Photo of the ready to load 79cc hot rodded engine.
Busy weekend I expect. Guinness and Harp to make a Black and Tan. What dreams are made of.
Tom
Tom
You on the wagon Tom? Couldn't help notice there's no can of brew on the bench in your latest photo.
Seriously though, if you haven't tried it before, give Guinness & Cider shot. Try mixing-up a Snakebite or two this weekend.
Seriously though, if you haven't tried it before, give Guinness & Cider shot. Try mixing-up a Snakebite or two this weekend.
Went to see Mona's Oncologist Dr. Steven Medlin in Milwaukee today. The Bone Marrow Transplant from her lab test was what he wanted to see. Next visit will be in July, a year since the BMT.
Today Dr. Steve said to Mona, that the BMT markers are what he liked to see. He said the word I long for again today remission. Mona is 74 years old but has Grand children 3 and 7. Grandma is not yet fixed into their long term memories.
Swapping engines starts Friday. Stay safe.
Tom
Today Dr. Steve said to Mona, that the BMT markers are what he liked to see. He said the word I long for again today remission. Mona is 74 years old but has Grand children 3 and 7. Grandma is not yet fixed into their long term memories.
Swapping engines starts Friday. Stay safe.
Tom
Guinness & Cider shot. Names and numbers matter Pete. Got a six pack of Harp in the discount bin for 5 USD. 1/2 price.
Guinness will come at a premium. Stout and cider? How can it be?
Tom
Guinness will come at a premium. Stout and cider? How can it be?
Tom
News worth waiting for, Tom, We're all so pleased for Mona, You and the Family. That big 'R' word is all everyone wanted to hear. 
Worth cracking open a can or two for this weekend.
Worth cracking open a can or two for this weekend.
No Flyer work today, making Mona happy by mowing our two acre wooded lawn was the thing.
After which at Pete's instigation gave a couple Snakebites a go. I can see where over indulgence could occur. Tasty.
Pete do you do the Snakebite & Black? Snakebite (drink) - Wikipedia
Got me thinking of planting Black Currents.
Tom
After which at Pete's instigation gave a couple Snakebites a go. I can see where over indulgence could occur. Tasty.
Pete do you do the Snakebite & Black? Snakebite (drink) - Wikipedia
Got me thinking of planting Black Currents.
Tom
Good job on the lawn Tom, mine needs it but we’ve had rain for 3 days.
it’s Friday night I’m gonna pick up some moonshine or vodka on the way to my GFs house.
You know alcohol will weaken your Willy. Ask an expert
Tom
Tom
Is that what’s happening to meYou know alcohol will weaken your Willy. Ask an expert
Tom
Biker to another Biker ask your GF and duck
Might be age related. I would still duck.
Tom
Might be age related. I would still duck.
Tom
Biker to another Biker ask your GF and duck
Might be age related. I would still duck.
Tom
It’s a fine line we walk