79cc Sportsman Flyer build
- Thread starter Tom from Rubicon
- Start date
Hi Pete,
I was just standing at the stove turning our ham and potato hash and there was a brief snow shower mixing in with the cold rain. 35F
Tom
Hi Rick,
Sorry but no update to report. I never got the carburetor fuel feed adjusted so that the engine would not stall under load. Too lean I think.
I ran out of riding weather last year, and this year? We take a long time warming up here in SE Wisconsin.
Snow showers as I write.
Tom
Mom always said the weather here in British Columbia was like the weather in the U.K. This spring has been wet and upper 40's to the upper 50's. The past few days were in the low 60's and yesterday it was 78F. That's a mid summer temperature. Today at 8am, it's 54 and overcast which is normal. It will rain of course. Tomorrow is supposed to be a repeat and then sunny and in the 70's for a couple of days.
Steve.
Steve.
Thanks. I thought I might have missed some posts Tom, but look forward to hearing your progres.
Rick C.
Hi Rick,
I understand your concerns. Notices of watched threads has for some time been iffy.
There is a air screw which as I understand it controls fuel mixture enrichment from 1/2 to full throttle.
I don't have a good understanding of the mechanics of carburetors. The Mikuni manual seems to make me think I need to open up that (air) circuit to enrich the fuel mixture. So why do they call it an air screw?
Is it the nomenclature that is tripping me up?
I would like to get this sorted out.
Tom
I understand your concerns. Notices of watched threads has for some time been iffy.
There is a air screw which as I understand it controls fuel mixture enrichment from 1/2 to full throttle.
I don't have a good understanding of the mechanics of carburetors. The Mikuni manual seems to make me think I need to open up that (air) circuit to enrich the fuel mixture. So why do they call it an air screw?
Is it the nomenclature that is tripping me up?
I would like to get this sorted out.
Tom
Hey Steve,
Good to hear from you. We all excepting Rick have been laying low over the winter months.
How is your health holding up?
Mona last saw her Oncologist a month ago and she is still in remission and well.
As mentioned above, I need to get the bloody Flyer carb sorted out.
Still waiting patiently for your TriCars tyres to touch ground. I know you were sorting out your work space.
I found a deceased mouse last week. I dare not speculate how it was in repose before I spied it.
And mouse droppings, everywhere! I really do not like mouse droppings.
Mona just called, so good night.
Tom
Good to hear from you. We all excepting Rick have been laying low over the winter months.
How is your health holding up?
Mona last saw her Oncologist a month ago and she is still in remission and well.
As mentioned above, I need to get the bloody Flyer carb sorted out.
Still waiting patiently for your TriCars tyres to touch ground. I know you were sorting out your work space.
I found a deceased mouse last week. I dare not speculate how it was in repose before I spied it.
And mouse droppings, everywhere! I really do not like mouse droppings.
Mona just called, so good night.
Tom
Tom I hope you bought a real Mikuni and received same. The counterfeits are just that and not replicas. They have authentic looking branding, but not the machining. I have one a (VM 24) I think, which I never got running right. The idle/air circuit is on the front, intake side of the carb. I close this gently then back off one &1/2 turns and that gets me close on an actual Mikuni, the clones I haven't a clue.....
Warm weather down here so it's slowly coming your way.
Rick C.
Warm weather down here so it's slowly coming your way.
Rick C.
If it will help, my 444 Case garden tractor, has a mixture screw also, I set mine by opening throttle slitly and set the Maine jet to the highest rpm, then about 1/8 turn rich. Then set the mixture screw so that when you crack the throttle it doesn’t bog down, this has worked good for years……….Curt
Hi Tom,
Great news about Mona. What a relief for you both. Not much different for me. Still trying to get one foot in front of the other some days and it's good other days.
I have been in the garage when I can cleaning it up and condensing junk so it can be thrown out. I've run out of space to put things away. My brother and I bought one of those tissue paper tin sheds but first we need to get a wood floor put together to set it on. With the winds we get and the wet snow falls it will need all the help it can get to hold together. This will give us a little space in the garage and there are plans to get a small dumpster/skip so we can toss a bunch of the crap lying around here.
I've been working on the camper getting it ready for a trip to Silverbear's for a Bike Camp. It's been 9 years since the last one. Need to get the paint for the Epic in a couple of weeks and the metal to finish Silverbear's fenders. We are 2-3 weeks behind what we should be as far as spring weather is concerned. Ever one is I think.
Steve.
Great news about Mona. What a relief for you both. Not much different for me. Still trying to get one foot in front of the other some days and it's good other days.
I have been in the garage when I can cleaning it up and condensing junk so it can be thrown out. I've run out of space to put things away. My brother and I bought one of those tissue paper tin sheds but first we need to get a wood floor put together to set it on. With the winds we get and the wet snow falls it will need all the help it can get to hold together. This will give us a little space in the garage and there are plans to get a small dumpster/skip so we can toss a bunch of the crap lying around here.
I've been working on the camper getting it ready for a trip to Silverbear's for a Bike Camp. It's been 9 years since the last one. Need to get the paint for the Epic in a couple of weeks and the metal to finish Silverbear's fenders. We are 2-3 weeks behind what we should be as far as spring weather is concerned. Ever one is I think.
Steve.
The 19mm clone unadjusted carb functioned well on the unmodified 79cc engine. but 3 hp on that heavy bike is a flat ground rider only.
Main jet mods never mattered and last year I was all over the map trying. I have not queried the fella at AGK. Now is the time. Or figure out a 212cc in this frame which is more than strong enough.
Plan A is a stock genuine 19mm Mikuni.
Tom
Good reports are pure joy, Pete.
I'm hoping the modified 79cc will reveal a couple more hp for you, once running.
I live in hilly terrain, some rather substantial grades, so even casual paced rides challenge single speed, centrifugal clutch builds with small displacement 4 cycle engines. I like the 212cc Predator a lot and it makes sense on the Sportsman, but I'd sure like to see the 79cc come to life!
Rick C.
I'm hoping the modified 79cc will reveal a couple more hp for you, once running.
I live in hilly terrain, some rather substantial grades, so even casual paced rides challenge single speed, centrifugal clutch builds with small displacement 4 cycle engines. I like the 212cc Predator a lot and it makes sense on the Sportsman, but I'd sure like to see the 79cc come to life!
Rick C.
This is what I'm working on 79cc ... Degree8 on ebay has your parts.. pwk needle jets
Attachments
This goes with it.. search sellers other items... Everything in one place...
Attachments
Good luck with this build...
Rick C.
Rick C.
Probably cause you’re not a crank addict, to build a motorcycle frame out of water pipe… but now you know what you need to do!
Tony, here is a link to the origin of this lovely adaptation of a Farmall Cub Tractor.
Guy Turns Old Tractor Into Badass Motorcycle » TwistedSifter
I think the oil can mounted behind to tractor tool box is what makes this build so right.
And you can get a rusty butt from the heavy duty saddle. As far as the frame is concerned?
I suspect it is a low cost proof of concept prototype.
Tom
Guy Turns Old Tractor Into Badass Motorcycle » TwistedSifter
I think the oil can mounted behind to tractor tool box is what makes this build so right.
And you can get a rusty butt from the heavy duty saddle. As far as the frame is concerned?
I suspect it is a low cost proof of concept prototype.
Tom
Last edited:
