Topic: Charging system improvements

[John V]

I'm looking at a 74-77 CB400F to pick up as a project bike. Does anybody have any suggestions on upgrading the alternator to increase its wattage? I want to build a fuel injection setup for the bike and will need more power at idle than the stock system can provide.

Thanks for any insight,

John

[lucky]

I'm looking at a 74-77 CB400F to pick up as a project bike. Does anybody have any suggestions on upgrading the alternator to increase its wattage? I want to build a fuel injection setup for the bike and will need more power at idle than the stock system can provide.

Thanks for any insight,

John

The alternator will be powerful enough since it is not all used for ignition in the first place. 2 out of 3 of the coils are used when the lights are on and there is still power left over.

I do not know why you would want to do this project.
The 4000F had plenty of power and worked very well.
I know because I was a Honda dealer mechanic at that time and bought one of the first 400F's.

I think you are just afraid of carburators. Or you just want to use your lap top to tune the bike instead of a screw driver.

[TwoTired]

The alternator will be powerful enough since it is not all used for ignition in the first place. 2 out of 3 of the coils are used when the lights are on and there is still power left over.

Some Hondas worked that way, but not the 400F.  All three stator coils work in unison to provide power in relation the magnetic field strength, which is controlled by the vreg.  Max output was 150 watts @5000 RPM and roughly 1/3 of that at idle RPM.  At idle RPM, the battery depletes with a standard load.  Adding more load will just make the battery deplete faster.

I saw a thread in this forum that promised 32 amps on CB750, converting to a permanent magnet type.  But, I didn't learn if that applied to other SOHC4s in the family.

Perhaps a search will find the thread?

[mono]

*popcorn*

[John V]

I'm looking at a 74-77 CB400F to pick up as a project bike. Does anybody have any suggestions on upgrading the alternator to increase its wattage? I want to build a fuel injection setup for the bike and will need more power at idle than the stock system can provide.

Thanks for any insight,

John

The alternator will be powerful enough since it is not all used for ignition in the first place. 2 out of 3 of the coils are used when the lights are on and there is still power left over.

I do not know why you would want to do this project.
The 4000F had plenty of power and worked very well.
I know because I was a Honda dealer mechanic at that time and bought one of the first 400F's.

I think you are just afraid of carburators. Or you just want to use your lap top to tune the bike instead of a screw driver.

Actually I'm not afraid of carbs at all. I've owned and worked on many carbureted motorcycles and have enjoyed getting them to run well with carbs. I just finished installing and tuning a Megasquirt system on my race car and it was a really fun project. I'm not interested in doing this for a performance improvement but rather for the challenge of doing it.

I have done quite a bit of searching about upgrading the charging system and haven't seen anything specific to the 400F. Was hoping somebody knew something but it sounds like I'm on my own here. No big deal!

[Tim2005]

I'll be interested to hear how you get on with this-  I have never seen a charging upgrade for the 400, though I'd like it one in order to run heated grips.  Many modern bikes have alternators that produce 300-400+watts yet are no bigger than a 400f's so it can't be impossible. What kinda output do you need to run fi? 

[John V]

I will need about 300W of total alternator output at idle. Maybe a little less, depends on how I implement the Microsquirt and the fuel pump needed for this. The stock system is nowhere near that at 5,000 RPM much less at idle.

I pick up this bike this weekend and plan to get it running well on the stock carbs first. It has pod filters on it right now (which I absolutely despise) so I'll be re-installing the airbox, cleaning the carbs and making sure everything is working correctly. The bike needs a good cleaning as well, new fork seals and fork oil and a thorough going-over.

[Jay Ace]

I do not know why you would want to do this project.
The 4000F had plenty of power and worked very well.
I know because I was a Honda dealer mechanic at that time and bought one of the first 400F's.

I think you are just afraid of carburators. Or you just want to use your lap top to tune the bike instead of a screw driver.

What an ignorant comment that makes absolutely no sense anyway.
I would think that anyone that is afraid of tuning carbs would be even more scared of injection conversion.

At any rate, regardless if it works or not, it's a cool project and it will be fun to watch!
I have no doubts that majority will be nay-sayers, as it is a trend with most non-restoration builds 

[Lostboy Steve]

I will need about 300W of total alternator output at idle. Maybe a little less, depends on how I implement the Microsquirt and the fuel pump needed for this. The stock system is nowhere near that at 5,000 RPM much less at idle.

I pick up this bike this weekend and plan to get it running well on the stock carbs first. It has pod filters on it right now (which I absolutely despise) so I'll be re-installing the airbox, cleaning the carbs and making sure everything is working correctly. The bike needs a good cleaning as well, new fork seals and fork oil and a thorough going-over.

Thats an insane amount of power. My wr250r is 350w at 5000 and thats the industry leader in that market. I think its done with rare earth magnets.

[Lostboy Steve]

I do not know why you would want to do this project.
The 4000F had plenty of power and worked very well.
I know because I was a Honda dealer mechanic at that time and bought one of the first 400F's.

I think you are just afraid of carburators. Or you just want to use your lap top to tune the bike instead of a screw driver.

What an ignorant comment that makes absolutely no sense anyway.
I would think that anyone that is afraid of tuning carbs would be even more scared of injection conversion.

At any rate, regardless if it works or not, it's a cool project and it will be fun to watch!
I have no doubts that majority will be nay-sayers, as it is a trend with most non-restoration builds 

Jay it depends. If hes a younger guy he may know a lot more about EFI systems than carbs. I was raised to work on old technology but most of my peers would be way more comfortable working on efi.

[John V]

I will need about 300W of total alternator output at idle. Maybe a little less, depends on how I implement the Microsquirt and the fuel pump needed for this. The stock system is nowhere near that at 5,000 RPM much less at idle.

I pick up this bike this weekend and plan to get it running well on the stock carbs first. It has pod filters on it right now (which I absolutely despise) so I'll be re-installing the airbox, cleaning the carbs and making sure everything is working correctly. The bike needs a good cleaning as well, new fork seals and fork oil and a thorough going-over.

Thats an insane amount of power. My wr250r is 350w at 5000 and thats the industry leader in that market. I think its done with rare earth magnets.

Modern fuel injected 600cc sportbikes generate 350-450W at 5,000 RPM and not much less at idle. My Speed Triple (also FI) puts out 420W. So 300W isn't that much power to drive a fuel injection system including the pump and all the stock lights.

I consider myself a young guy... I'm 35. But as I said, I am perfectly comfortable working on carburetors. I've been down that road many times though I'm certainly less experienced than many people. I just enjoy new challenges!

[anders288]

I will need about 300W of total alternator output at idle. Maybe a little less, depends on how I implement the Microsquirt and the fuel pump needed for this. The stock system is nowhere near that at 5,000 RPM much less at idle.

I pick up this bike this weekend and plan to get it running well on the stock carbs first. It has pod filters on it right now (which I absolutely despise) so I'll be re-installing the airbox, cleaning the carbs and making sure everything is working correctly. The bike needs a good cleaning as well, new fork seals and fork oil and a thorough going-over.

Thats an insane amount of power. My wr250r is 350w at 5000 and thats the industry leader in that market. I think its done with rare earth magnets.

Modern fuel injected 600cc sportbikes generate 350-450W at 5,000 RPM and not much less at idle. My Speed Triple (also FI) puts out 420W. So 300W isn't that much power to drive a fuel injection system including the pump and all the stock lights.

I consider myself a young guy... I'm 35. But as I said, I am perfectly comfortable working on carburetors. I've been down that road many times though I'm certainly less experienced than many people. I just enjoy new challenges!

     You need to install a modern alternator. It's the only way your going to get enough power supply the EFI. I have a 32amp. alternator on my K7 and put 6K miles on it this year.
  it can be done

[John V]

Thanks for the post. Do you have any information I can read regarding what you did?

[anders288]

Thanks for the post. Do you have any information I can read regarding what you did?

               Here you go http://forums.sohc4.net/index.php?topic=117735.0;nowap

[John V]

Looks like you have an upgrade for the 750 but the 400 is a different beast. Have you thought about tackling the 400? Did you start with a particular bike's flywheel and stator?

Thanks

[Sami1987]

Artic Cat has been running battery-less efi for years. Maybe you could check out their system. Good luck.

[anders288]

Looks like you have an upgrade for the 750 but the 400 is a different beast. Have you thought about tackling the 400? Did you start with a particular bike's flywheel and stator?

Thanks

                                     I would start buy looking at the CBR600RR 09-12 looks like it would be a good place to start