Topic: Fuel injection conversion (edit) fixed a few things

[JohnG]

Sam mentioned possible alternator improvement from 750A parts.  According to Honda's literature, the 750A puts out 290W   whereas CB750s and 750Fs  put out 210.  You need to swap both the stator assembly and rotor.

   john

[754]

Not sure if cutting out centre will help, might though, were you thinking to weld it back together, dont want it coming off..

 The problem with cutting taper is 20 thou bigger on diameter moves it out quite a bit, so the tapears have to be accurate..

 The trick I use to set up tapers is to get the angle close, use chalk to test fit, then mount a dial indicator, on the compound . Use this for your adjusting to get your angle set, if you are tapping the slide over without it, you never know where you are at..

[750essess]

I was thinking to cut out the center of the original flywheel as a start for the spacer. Then the inside taper would be already there and would only have to cut the outside taper on the piece that was cut out. That make sense?

[754]

I would not go to that much work to avoid cutting one taper.

 If the tapers are the same it could be cut in one setup on a manual lathe, its just easier to be exact if you cut, in a manner where you can test fit your crank, mount adapter, then cut 2nd taper till the rotor fits, diameter will affect the in/out spacing of the rotor, so it gets tricky.

 I think where most have trouble with the taper setting, is the fine adjustment, the dial indicater, makes that much quicker @ easier.

 Also you may have to cut several pieces, to get it right, just part of the job.. its turning it around or taking in or out of the lathe, that can cause runout, worse if your chuck is not accurate..

 If your machinist has any questions re cutting the taper or setting it up, we can help out.

[750essess]

Ok thanks for the input

[bucky katt]

Sam mentioned possible alternator improvement from 750A parts.  According to Honda's literature, the 750A puts out 290W   whereas CB750s and 750Fs  put out 210.  You need to swap both the stator assembly and rotor.

   john

i wonder if anyone here has done the conversion and if so, wouldnt it make a great sticky topic?

[750essess]

The conversion to the automatic parts would probably give you enough power, but u would still be dealing with old parts. The permanent mag system is in my opinion a better solution. The parts for the conversion are at the machinist now, should be done soon. Have to order a vfr800 regulator still. Will post pics of the parts when they are finished.

[J.Webster Designs]

Let us know how it turns out 750.... I am highly interested in figuring out how to get more power out of the electrical system so i can run the injection without worrying or constantly turning on and off my headlight.

[750essess]

Machinist called this morning, parts are done, handed me bill , $458 !!!!! I said it was too much. Owner says he will see what he can do and call me, haven't heard from him yet. Had 8 hrs on the bill, i dont see how he could have 8hrs in it.

[JAG]

So I apologize ahead for my ignorance, but is this Not going to be sold anymore as a kit?

This thread has been going awhile, and I'd love to do this. Is there a lot more work involved in adapting EFI to our bikes then what was originally thought? Or can I go out and buy this, this, and this, and bolt it up and go??

Sorry again, I just wanted to get to the brass balls of the situation. You guys can kick my A** later. 

Thanks
JAG

[J.Webster Designs]

this is very far from just a bolt on and go modification.... there will be lots of modification required as well as tuning after the install is completed.

[754]

Its a prototype..
 Dont know how long it will take

 Dont know how much it will cost

 Wont know till the end , if you could do it for someone else, or would want to..

 Man that machinist, sounds like he is not comfortable cutting tapers, that is a Lot of hours.. I was speaking more in terms of walking someone thru it that had not done it before (or was uncomfortable cutting an accurate taper). I have to say, I did run it thru my mind several ways and weighed the pros & cons of a couple methods.. guy on the shop floor maybe was not given that option.. you gotta ask for a ballpark price first..

[750essess]

So I apologize ahead for my ignorance, but is this Not going to be sold anymore as a kit?

This thread has been going awhile, and I'd love to do this. Is there a lot more work involved in adapting EFI to our bikes then what was originally thought? Or can I go out and buy this, this, and this, and bolt it up and go??

Sorry again, I just wanted to get to the brass balls of the situation. You guys can kick my A** later. 

Thanks
JAG

The only thing you just cant go and buy are the intake manifolds, they turned out to be too costly to offer for sale.

[750essess]

Ok, agreed on $400 bucks for the parts, here are the pics
starter ring gear and clutch installed on vfr800 flywheel


adapter to mount vfr800 flywheel on cb750 crank


adapter to mount stator in cb750 cover


parts installed but not bolted in



Cant get dimensions right now my digital caliper decided to quit working, got the reg/rec today too will get this put together and tested on saturday.

[J.Webster Designs]

sounds good.... keep us posted

[Soos]

This looks awesome so far.


I wonder how much different the cb650 would be for this mod VS. the 750......
VERY interested in seeing/reading of your results!!!!




Being a machinist this REALLY interests me.
The shop bill would be.... oh yeah, time invested only.



Too bad I am a electrical idiot in general.(I once started a fire wiring in a 120V wall outlet...)








l8r

[bucky katt]

that setup looks freakin AWESOME!

[750essess]

IT WORKS!!!!! Only problem was getting the old flywheel off, was pretty stubborn. Puts out 14.8 volts at idle, 14.5 with high beam on. Oh and the lighter flywheel makes it rev real nice.

[J.Webster Designs]

what about amps? are you running the VFR voltage regulator and everything as well? the only peices needed to do it were the adapter for the flywheel and the adapter for the stator?

[750essess]

If its maintaining volts it providing enough amps. You also need to drill the flywheel for the starter clutch. Yes using the vfr8000 reg/rect.

[greasy j]

IT WORKS!!!!! Only problem was getting the old flywheel off, was pretty stubborn. Puts out 14.8 volts at idle, 14.5 with high beam on. Oh and the lighter flywheel makes it rev real nice.

awesome!

nice work Dr. Bikenstein

[754]

Man sounds like it works great!

 When we were talking time involved, I had thought you meant cutting the taper adaptor.. the other parts and work required , is a lot more work.

 If you now measure those parts, the job gets a lot easier.

 How much did you pay for the VTR parts.. My gut says, your average wrecker/salvage yard is goint to charge near 40 or 50 % of new, in most cases, so I am thinking at least 300 for the "new" parts, plus machining.. somehere in that range.

 Any weight comparison between the stock rotor, and the VFR ?

[750essess]

Yeah I realized I flew off the handle a little bit about the price, he cut the double taper machined and figured out the size of the stator adapter and drilled the flywheel for the starter clutch all for that price. I bought the vfr parts along time ago off ebay, iirc it was about $150 for the rotor and stator. I got the stator cheap cause it had the connector cut off. I meant to weigh the flywheel but forgot, just guessing I would say it about half the weight. All I got to measure the pieces with is a cheap manual caliper +- .1 mm plus user error LOL. Please only use these measurements as guide, some adjustment may be nescessary. The crank adapter is approx 19.4mm small end inside. 23mm small end outside. 24.5 mm big end inside. 28 mm big end outside. The stator adapter diameter where it attaches to cover is 89.4mm. 63.3mm diameter on stator side. Has a hole 38.5 through the middle. Total thickness is 19mm (this is the measurement that is hard to get with out some trial and error). The thickness of the flange on the cover side is 8.5mm. Had no good way of measuring bolt locations. If I get some time I will make up a drawing, will make it clearer. Also will need to make a guide to hold the wires out of the way. I just welded on an extension to the stock wire guide. Need button head screws for clearance on the stator, stock ones ok for mount to cover. Used the thick crank washer (thick kind)from an early motor on the bolt from a later one (shorter). The flywheel is not as thick as the stock one. Another not is the vfr reg is a linear reg type inlike the stock one that controls the output of the alternator. This means it drops excess power by heat. I measured the reg and it got to 135 deg. Checked some forums and this is about normal. So mount it somewhere where it can get some air. I put mine on the old horn bracket. So whats the total.... $400 machine work, $150 vfr flywheel, stator. Reg/rec from electrosport $99, total $650. Having no more charging problems on your 76 cb750 converted to fuel injection...priceless.

[754]

Looks like a lot of it hinges on used parts availability, so probably in the 5-800 range of cost. we should check Honda price for new.

 I am thinking, it seems you said that the parts are not as far out from the cases, which tells me that there could be a slimmer Alternator cover mod, more clearance..

 Is that setup run wet or dry in stock application?

[Retro Rocket]

Yeah I realized I flew off the handle a little bit about the price, he cut the double taper machined and figured out the size of the stator adapter and drilled the flywheel for the starter clutch all for that price. I bought the vfr parts along time ago off ebay, iirc it was about $150 for the rotor and stator. I got the stator cheap cause it had the connector cut off. I meant to weigh the flywheel but forgot, just guessing I would say it about half the weight. All I got to measure the pieces with is a cheap manual caliper +- .1 mm plus user error LOL. Please only use these measurements as guide, some adjustment may be nescessary. The crank adapter is approx 19.4mm small end inside. 23mm small end outside. 24.5 mm big end inside. 28 mm big end outside. The stator adapter diameter where it attaches to cover is 89.4mm. 63.3mm diameter on stator side. Has a hole 38.5 through the middle. Total thickness is 19mm (this is the measurement that is hard to get with out some trial and error). The thickness of the flange on the cover side is 8.5mm. Had no good way of measuring bolt locations. If I get some time I will make up a drawing, will make it clearer. Also will need to make a guide to hold the wires out of the way. I just welded on an extension to the stock wire guide. Need button head screws for clearance on the stator, stock ones ok for mount to cover. Used the thick crank washer (thick kind)from an early motor on the bolt from a later one (shorter). The flywheel is not as thick as the stock one. Another not is the vfr reg is a linear reg type inlike the stock one that controls the output of the alternator. This means it drops excess power by heat. I measured the reg and it got to 135 deg. Checked some forums and this is about normal. So mount it somewhere where it can get some air. I put mine on the old horn bracket. So whats the total.... $400 machine work, $150 vfr flywheel, stator. Reg/rec from electrosport $99, total $650. Having no more charging problems on your 76 cb750 converted to fuel injection...priceless.

Extremely well done mate, this is the sort of stuff that makes this forum a hugely valuable resource...

Mick