Cam/ Viper adict
New member
What kind of ultralite are you building? I have my pilots licence and have flown all types of aircraft and ultralites.
Canuck Bob
New member
Cam/ Viper adict said:
In Canada we call ultralights anything under 1200 lbs and of course lots of rules regarding hp and wing area and landing speeds (45 mph). I currently own a Bowers Fly Baby with a Cont A65, it qualifies. It is being totally rebuilt to lighten it and check its structure. I will probably try to fit the Yamaha once the Weight and balance numbers are known. Once it is airborne again I'll start one of the following.
I have narrowed my choice a bit but it maybe the Spacewalker single seat, a single seat Sisler Cygnet or one of Wag Aero's Piper copies, the J3 or Wagabond again modded for single seats. These planes qualify if built light.
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Canuck Bob
New member
Here's the first preliminary draft concept.
redhead engine with lower mileage, probably a wrecked or operating sled for all the OEM equipment like wiring harness, coolant system outside the motor, exhaust, airboxes etc..
use a factory stock engine refreshed with new rings and seals and gaskets as required
notch reed frame, and/or add spacer, and/or add carbon tec reeds in factory frame. I'd really appreciate input here. Many threads say the stock reeds and cage are pretty good as is. A couple horsepower is meaningless to me but smooth responsive power is the goal.
Operate at 8000 rpm for takeoff and initial climb, max sustained 2 minutes, and 6000 rpm or less for all other flight regimes.
Install an Atacc compensator to help with the broad range of temp. and altitude for a year round flyer, again real world advice welcome here.
One thing, I was shocked at the cost of performance parts! Anything here worth the cost for my application? I am real cheap!
redhead engine with lower mileage, probably a wrecked or operating sled for all the OEM equipment like wiring harness, coolant system outside the motor, exhaust, airboxes etc..
use a factory stock engine refreshed with new rings and seals and gaskets as required
notch reed frame, and/or add spacer, and/or add carbon tec reeds in factory frame. I'd really appreciate input here. Many threads say the stock reeds and cage are pretty good as is. A couple horsepower is meaningless to me but smooth responsive power is the goal.
Operate at 8000 rpm for takeoff and initial climb, max sustained 2 minutes, and 6000 rpm or less for all other flight regimes.
Install an Atacc compensator to help with the broad range of temp. and altitude for a year round flyer, again real world advice welcome here.
One thing, I was shocked at the cost of performance parts! Anything here worth the cost for my application? I am real cheap!
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Triple X
New member
The Redheaded engine is the better choice for this application. These engines have a very wide power band, they will make 110hp from 7500rpm - 8500rpm. If you are not interested in the extra 2-3hp, I would stick with the stock reeds & cages and maybe some reed spacers. Stay with a stock engine this will give you drop dead reliability (sorry for the pun) and years of safe use. Sometimes with the reed cage notch and after market carbon reeds they (the reeds) have a tendency to break, thats something you do not want to happen when flying with the birds. I would be interested in seeing some pictures when you get this thing airborne.
Merged the two threads. Good luck with your project!
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Canuck Bob
New member
Thanks crewchief, this forum is a great bunch.
3 words for you, keep it stock. Even down to the reeds. If you do any mods like pipes then you get into jetting issues and cooling. And like said before aftermarket reeds have been known to break. We bought our one 97 SX 700 with 3000 miles on it. Now 4500 miles later we still have the same reeds in it.
Not sure on the Atacc but just jet for the summer and then rejet again come winter. Jet for the altitude and temps you will take off at because as you go up higher it will just run richer is all.
Not sure on the Atacc but just jet for the summer and then rejet again come winter. Jet for the altitude and temps you will take off at because as you go up higher it will just run richer is all.
Canuck Bob
New member
SXlover said:
The more I research the more this is good advice. I am not familiar with the jetting process but am learning fast.
Should I notch the cage or add a spacer?
I would recommend the spacer over the notch if only for reliability. The notches have been reported to crack if done poorly and then you risk a power issue. The spacer has no negative save for the extra gasket which would be less of a concern.
Many TY members's would probably suggest that after market reeds are a waste unless you have the motor ported. If you contact MrViper700 he may give you more info as it relates to the reeds and other red head points. You can try PM'ing him, he may still be lurking at TY or you can track him down over at hardcoresledder.
Many TY members's would probably suggest that after market reeds are a waste unless you have the motor ported. If you contact MrViper700 he may give you more info as it relates to the reeds and other red head points. You can try PM'ing him, he may still be lurking at TY or you can track him down over at hardcoresledder.
Canuck Bob
New member
SXlover said:
I'm guessing a little richer with altitude also means a little cooler running? Lean means burnt valves in 4 strokes a little rich means valves never burn.