dave patrick ultimate 40 arf
09-22-2008, 06:12 PM
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dave patrick ultimate 40 arf
Hi all; i am building a ultimate and i have a saito 56 mounted sideways on the firewall, and this leaves the fuel tank centerline 1" lower than centerline of carb. Will this cause a problem with rich/lean flights? what fix if any. the local hobby guy who sold it to me(without telling me dave patrick is out of business) says cut the fuse wide brace out to move the tank up. this looks like a bad idea, as the struts that go to the wing attach here. Any help would be appreciated. George
09-30-2008, 04:35 PM
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RE: dave patrick ultimate 40 arf
Stryder,
The centerline of the fuel tank being 1: below the carb centerline will be too low. 4-strokes pull fuel better than 2-strokes, but in my opinion, 1" is too much. You should be shooting for the fuel tank centerline being about 3/8" maybe 1/4" below the carb centerline. I believe it will be too lean especially as your flight progresses. You might not spend a ton of time inverted, but in that attitude you will be rich. If you cant figure a way to raise the level of the tank, you may need to add a pump.
I also just bought a DP .40 Ultimate which is still enroute from the seller. I have an Aviastar .46 that is looking for a home so that is my plan right now. I would mount that sideways so I might have the same problem. I must say I am surprised by what you are finding as the instructions specifically show the engine mounted sideways and from what I can discern from the pictures, the tank to engine positioning looks very close to what I have described above.
Le me know how it goes.
Cheers,
Ernst
The centerline of the fuel tank being 1: below the carb centerline will be too low. 4-strokes pull fuel better than 2-strokes, but in my opinion, 1" is too much. You should be shooting for the fuel tank centerline being about 3/8" maybe 1/4" below the carb centerline. I believe it will be too lean especially as your flight progresses. You might not spend a ton of time inverted, but in that attitude you will be rich. If you cant figure a way to raise the level of the tank, you may need to add a pump.
I also just bought a DP .40 Ultimate which is still enroute from the seller. I have an Aviastar .46 that is looking for a home so that is my plan right now. I would mount that sideways so I might have the same problem. I must say I am surprised by what you are finding as the instructions specifically show the engine mounted sideways and from what I can discern from the pictures, the tank to engine positioning looks very close to what I have described above.
Le me know how it goes.
Cheers,
Ernst
