I have a 1984 Honda Aero that I just got running via new spark plug, new fluids and about 5 kicks so it's not that dusty. I went on the first ride up and down my street and thought I was in for a pleasant surprise when it whipped forward with very nice acceleration but then about 3 seconds later I was stuck sputtering at 15mph. It like * and lurches and bogs down like crazy if I open throttle past a very specific point. If I hold it wide open it seems like it wants to die. Im also struggling with a consistent idle until it warms up, then it seems fine. Not so worried about that as I'm fairly confident I can figure that out unless you have some time saving pointers. For now I want to know what I need to look at to go a safe speed for on the road. Is it maybe not variating? If so I'm clueless there, I've never messed with that yet. I'm certainly a novice with these I just enjoy fixing up old barn finds that wouldn't ever see the road again.
Thanks a ton.
Honda Aero Stops accelerating at 15MPH?
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Wheelman-111
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Re: Honda Aero Stops accelerating at 15MPH?
Greeting:
90% of the issues seen with older "barn finds" are fuel system issues.
If the spark plug is new and compression is good - find Test Procedures in the Service Manual - then it's not getting the right amount of fuel in the correct admixture.
Start at the fuel tank, check the operation of the vacuum petcock, consider REPLACING all rubber lines, including the vacuum line, consider adding an inline Cone O' Stone fuel filter and then remove and dismantle the carb for a thorough inspection and cleaning. Pay particular attention to the little Bystarter "mini-bowl" and the tiny brass "jet" that enables its contents to pass into the intake charge. The Pilot circuit is actually a fixed-size hole in the venturi adjacent to the main jet tower. It's tiny, thus easily clogged with evaporated fuel resin. Also verify that the float needle assembly is performing correctly. Consider a NEW float needle even if yours APPEARS to be OK. It can stick in its little bore, and the rubber conical end can become brittle and fail to seal properly.
The other ingredient for your Intake mixture is the Air side. A NEW filter element sealed tightly in an intact airbox with solid connections is critical to correct operation. Verify that all of it is in good working order.
If the carb is demonstrably re-habbed, check for intake vacuum leaks. You can use an UNlit propane torch to fumigate suspected joints about the reed cage, exhaust manifold, and crank end seals.
If all that is OK, then depending on mileage it could be an exhaust pipe clogged with carbon and/or rust. Step-by-step muffler cleaning methods can also be found in the Tech sections.
Good luck!
90% of the issues seen with older "barn finds" are fuel system issues.
If the spark plug is new and compression is good - find Test Procedures in the Service Manual - then it's not getting the right amount of fuel in the correct admixture.
Start at the fuel tank, check the operation of the vacuum petcock, consider REPLACING all rubber lines, including the vacuum line, consider adding an inline Cone O' Stone fuel filter and then remove and dismantle the carb for a thorough inspection and cleaning. Pay particular attention to the little Bystarter "mini-bowl" and the tiny brass "jet" that enables its contents to pass into the intake charge. The Pilot circuit is actually a fixed-size hole in the venturi adjacent to the main jet tower. It's tiny, thus easily clogged with evaporated fuel resin. Also verify that the float needle assembly is performing correctly. Consider a NEW float needle even if yours APPEARS to be OK. It can stick in its little bore, and the rubber conical end can become brittle and fail to seal properly.
The other ingredient for your Intake mixture is the Air side. A NEW filter element sealed tightly in an intact airbox with solid connections is critical to correct operation. Verify that all of it is in good working order.
If the carb is demonstrably re-habbed, check for intake vacuum leaks. You can use an UNlit propane torch to fumigate suspected joints about the reed cage, exhaust manifold, and crank end seals.
If all that is OK, then depending on mileage it could be an exhaust pipe clogged with carbon and/or rust. Step-by-step muffler cleaning methods can also be found in the Tech sections.
Good luck!
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Re: Honda Aero Stops accelerating at 15MPH?
Well, thanks a ton for all that man. I'm heading to get an inner tube for another bike then I'm going to look into it. Carb has been very thoroughly cleaned and appears to be operating fine. I ordered a new air filter but I'm waiting for it. What I am still guessing on is where the carb should be adjusted to with the air a fuel screws. Could that be part of it? Not having those screws set right? I've tried a lot of adjusting though and not much change.
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Wheelman-111
- Moderator
- Posts: 10683
- Joined: Wed Oct 22, 2008 5:09 pm
- Location: Deepinnaharta, Texas
Re: Honda Aero Stops accelerating at 15MPH?
Greetings:
There is absolutely NO point in messing with the mixture screws if the filter element isn't in situ and properly oiled and snugly fitted. I hope at least you recorded its previous position so you could set it about where it was?
There is absolutely NO point in messing with the mixture screws if the filter element isn't in situ and properly oiled and snugly fitted. I hope at least you recorded its previous position so you could set it about where it was?
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Re: Honda Aero Stops accelerating at 15MPH?
It didn't even have one, so I'll just sit tight on that bike until I get the filter in a few days then. That's good to know, means I wasted a lot of time turning screws ha ha!
Re: Honda Aero Stops accelerating at 15MPH?
Dogdog54...I am located in Nashville also... 
I ride Aeros too, and am glad to help you with any work you are not fully sure about...
I will send you a Private Message (PM) with some contact info.
..........................................Rock-on....................................
I ride Aeros too, and am glad to help you with any work you are not fully sure about...
I will send you a Private Message (PM) with some contact info.
..........................................Rock-on....................................
RideRed
<Helix><(2)Gyro S><Rebel><CB100><Urban Express><Aero 50>
"Live Large - Ride Small"
<Helix><(2)Gyro S><Rebel><CB100><Urban Express><Aero 50>
"Live Large - Ride Small"
Re: Honda Aero Stops accelerating at 15MPH?
Check the variator & rollers for condition. Flat or chunked up rollers, or crud in the front variator assembly will affect the "shifting"Dogdog54 wrote:I have a 1984 Honda Aero that I just got running via new spark plug, new fluids and about 5 kicks so it's not that dusty. I went on the first ride up and down my street and thought I was in for a pleasant surprise when it whipped forward with very nice acceleration but then about 3 seconds later I was stuck sputtering at 15mph.