Ranger
XS650 Addict
Just to be clear 2M, you think I should stick with the 1-wire alternator, but try and make it turn on and charge more consistently at a lower RPM. Then just slightly upside the crank pulley?
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Ranger's 2016 xs650 chopoff build
- Thread starter Ranger
- Start date
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- Tags
- build chopoff chopper fabrication
westonboege
XS650 Addict
Nice job! I was hoping it was a supercharger at first too!
Yeah, that's pretty much it.
I'd have that thing cracked open before yesterday, see what makes it tick.
Your posted alternator spec sheet has a hint of an output curve on the bottom.
I'd also be looking at that curve, extrapolating it to the lower rpms, see where it goes...
TimmerTPA
XS650 Member
Hey Ranger. Hugh is probably the most knowledgeable person in the world when it comes to the XS, but I run the single carb on both of my xs chops and for me it's perfect. No more leaks because the carbs are too heavy, only tuning 1 carb instead of 2. I really like the way mine perform. I don't have anything that I dislike about either of my setups. More riding and less jacking around with the carbs!!!! Good luck. Can't wait to see the bike! Hoping to get to the chop off at Dan this year! Tim
Ranger
XS650 Addict
What carbs are you running? You definitely should come out to Dan's. It's always a good time.
TimmerTPA
XS650 Member
I'm running vm36 on both of mine. I have a pretty good jet recipe I can dig up for you if you go that route?? Marvin (Joe wiseguy ) and wes from counter balance made the 2 manifolds that I've used. Everyone has their own theory as far as what works and what should and shouldn't work, but I can tell u first hand that they work well!!! Sure..you Prob can't get them dialed in like a set of Lectrons, but they are simple and effective in my opinion. I'm going to try to find u on IG and follow you. If u click on my IG u can Prob find a pic??? On my black xs (Jays old xs) I have an elbow coming off the manifold to carb and tucks up under the seat! Looks killer! Not sure if I have a pic of it mounted on my ig, but I can get you one. Tim
TimmerTPA
XS650 Member
Also, you can pick up a brand new mikuni vm 36 on ebay for around $100. Just make sure it's the real deal and not a knock-off from china!
Ranger
XS650 Addict
I'm thinking bout building an intake that sends the carb straight back, since I'm building the frame anyway. Any idea whether a VM36 would be large enough if I go with a 750 kit? Not sure what motor work I'll have time/money for, but I'd really like to do a 750 kit/rephase. But worst case I have a stock motor with good compression, so I might end up going that route if I run out of time.
weaselbeak
XS650 Junkie
I have mini alternators on a couple of Moto Guzzis. Here is one of them during the build
I also have a 3rd in use on a trike, motor drives a jackshaft and it only charges while under way. It's not a problem there as the trike uses a series 24 car battery, so sitting or very low speeds are no problem. It charges 14 volts by the time I get to 25 MPH. I don't currently have a picture of that saved anywhere that shows it up close. They all 3 work fine without issues. Your mockup has been done before and I see nothing wrong with it. It's nice to eliminate the R/R and all the wiring that goes with it. BTW, 2 of mine are 1 wire alternators and the 3rd is a 3 wire. Easy either way. Both Guzzis have taken road trips, one a 2000 mile trek into Canada. The only thing to worry about on that single carb that I can see is to make sure you use a double down back tube on the frame so you can run your intake out the center. That will keep the 2 cylinders at equal length on the runners. Also keep the runner as short as possible so heat from the engine can warm it adequately. Otherwise you fuel will drop out of suspension and you'll have to be running really rich and not at all efficiently. Wrapping the runner will also help keep heat in it for atomization purposes. I went thru this putting a Fiat 850 sport 2 stage 2 bbl on a Honda 750. Remember, if it ain't different, why bother?
I also have a 3rd in use on a trike, motor drives a jackshaft and it only charges while under way. It's not a problem there as the trike uses a series 24 car battery, so sitting or very low speeds are no problem. It charges 14 volts by the time I get to 25 MPH. I don't currently have a picture of that saved anywhere that shows it up close. They all 3 work fine without issues. Your mockup has been done before and I see nothing wrong with it. It's nice to eliminate the R/R and all the wiring that goes with it. BTW, 2 of mine are 1 wire alternators and the 3rd is a 3 wire. Easy either way. Both Guzzis have taken road trips, one a 2000 mile trek into Canada. The only thing to worry about on that single carb that I can see is to make sure you use a double down back tube on the frame so you can run your intake out the center. That will keep the 2 cylinders at equal length on the runners. Also keep the runner as short as possible so heat from the engine can warm it adequately. Otherwise you fuel will drop out of suspension and you'll have to be running really rich and not at all efficiently. Wrapping the runner will also help keep heat in it for atomization purposes. I went thru this putting a Fiat 850 sport 2 stage 2 bbl on a Honda 750. Remember, if it ain't different, why bother?
member3480
RICH
I use to do that alternator setup on one of my GS1100 and used a GPZ alternator. Small and easy to place. Will look cool when done
I'm going to watch this build with interest, the alternator should not be a problem if you put a smaller pulley on the alternator and one slightly larger on the crank and I'm pretty sure the cooling fan issue will be overcome quite easily.
Ranger
XS650 Addict
Thank God for all the old-timers out there. I stopped by Brazosport Starter and Alternator yesterday and spoke with Gus and Harold. It's the only alternator shop in the area, and I didn't even realize they were still open.
Gus replaced the V-belt pulley with a smaller (50mm) 4-groove serpentine pulley he had laying around. He said a serpentine pulley would make that small bend easier, and would be easier to tension. He's also ordering me an 80mm steel pulley that I will modify to work on my crank. That gives me a ratio slightly larger than 1.5:1.
So according to the data sheet that came with the alternator, at this ratio, it should kick on between 800 and 900 engine RPM. (The sheet says the alternator doesn't turn on until 1490 RPM, but the curve actually starts at 1200 RPM, indicating that's when it actually turns on).
So it's looking like about 9 amps at 1000 RPM, about 15 amps at 1200 RPM, and about 20 amps at 1,400 RPM.
While I had it in the shop, they tested it and said it put out 14.8 Volts.
So, it looks like I'm good to go, and I've spent less than $15 at the alternator shop.
I also asked Gus about the fan, and he said it would actually cool in either direction.
On a side note: He also said there was no way to make the alternator turn on at lower RPMs, but he did say that is could be converted from 1-wire back to 3-wire if I wanted to.
Gus replaced the V-belt pulley with a smaller (50mm) 4-groove serpentine pulley he had laying around. He said a serpentine pulley would make that small bend easier, and would be easier to tension. He's also ordering me an 80mm steel pulley that I will modify to work on my crank. That gives me a ratio slightly larger than 1.5:1.
So according to the data sheet that came with the alternator, at this ratio, it should kick on between 800 and 900 engine RPM. (The sheet says the alternator doesn't turn on until 1490 RPM, but the curve actually starts at 1200 RPM, indicating that's when it actually turns on).
So it's looking like about 9 amps at 1000 RPM, about 15 amps at 1200 RPM, and about 20 amps at 1,400 RPM.
While I had it in the shop, they tested it and said it put out 14.8 Volts.
So, it looks like I'm good to go, and I've spent less than $15 at the alternator shop.
I also asked Gus about the fan, and he said it would actually cool in either direction.
On a side note: He also said there was no way to make the alternator turn on at lower RPMs, but he did say that is could be converted from 1-wire back to 3-wire if I wanted to.
Ranger
XS650 Addict
Words to live by! Thanks for sharing your experiences!
I've thought about using an alternator from a motorcycle. GPZ, BMW, Gold Wing, etc... Do you just replace the cush drive with a pulley? I'm going to stick with my current setup, but it's nice to know there's other options for future craziness!
Yup, that's what the alternator guys helped me determine... can't wait to get this thing nailed down!
weaselbeak
XS650 Junkie
I have all 3 of my alternators in the vicinity of 1.5-1 on the pulleys.
Ranger
XS650 Addict
I love it when the UPS guy shows up with parts... It's like he's Santa Claus, and it's Christmas, except I paid for everything... hmmm... so it's exactly like Christmas...
Here's what I got... doesn't seem like a lot for $300
18" shouldered hoop
Stainless spoke kit for the 18" hoop
Locking tabs and bolts for the brake rotor and sprocket
Spoke nipple wrenches
Rear brake shoes
Stainless spoke kit for lacing a front 36 spoke hub to a 21" hoop
Now I need a nice 21" shouldered 36 spoke hoop. I've seen some new repops on ebay that I'm considering, unless I can find a vintage one in really good shape.
Here's what I got... doesn't seem like a lot for $300
18" shouldered hoop
Stainless spoke kit for the 18" hoop
Locking tabs and bolts for the brake rotor and sprocket
Spoke nipple wrenches
Rear brake shoes
Stainless spoke kit for lacing a front 36 spoke hub to a 21" hoop
Now I need a nice 21" shouldered 36 spoke hoop. I've seen some new repops on ebay that I'm considering, unless I can find a vintage one in really good shape.
Didn't read the whole thread yet, but wanted to get this in. We have been using the Hitachi and Denso alternators on GoldWings for quite a while now. Your RPMs must be close to the GL's, idle is what matters. What works well on the GLs is 2" pulley on the alternator and 3-1/2" pulley on the crankshaft. The alternator does not have to be charging at idle but should charge somewhere close to, just above idle, most MCs stock systems do the same. I used the Denso alternator, easier to service the voltage regulator, but the Hitachi may have a better look for you. To clear your slave cylinder you could use an idler pulley. A 3/8", 10mm alternator pulley can work just fine with a 1/2" belt if needed for the crankshaft pulley.
Scott
Edit, I see you may use a flat belt, yeah you have the room for that, GoldWings are tight clearances everywhere. And, that pulley ratio is a good one.
Scott
Edit, I see you may use a flat belt, yeah you have the room for that, GoldWings are tight clearances everywhere. And, that pulley ratio is a good one.
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Ranger
XS650 Addict
Thanks for the info! Good stuff! Yeah, I bought an inexpensive Denso off Ebay, toying with the idea of an idler. I'll make the final decision once I finish tweaking the sidecover design.
Ranger
XS650 Addict
My Premium Exhaust kit (with a few extra bends I asked for) arrived the other day from Pandemonium, along with front and rear wheel bearings and a starter delete.
Ranger
XS650 Addict
I love the clean look of a spool or mini drum front end... But I just couldn't bring myself to do that on this build because I'm planning to ride this bike with my 10-year-old son.
But the fact that I'm building my own girder front end leaves me open to a plethora of options. I'm still running a factory xs650 front hub, so I need a rotor with the same bolt pattern, but with less offset, as the girder I'm building will only have 5" between the legs... Not enough room for the factory rotor. Plus, let's be honest, even drilled and powdercoated the factory rotor is hideous.
I'm planning to go with one of the 320mm rotors off a Ducati M900, as soon as I can find one reasonably priced and in good shape.
Because I won't have a whole lot of room behind the rotor, I couldn't go with a nice 4 piston Brembo like the one Pandemonium offers in their kit. They're just too fat on the back end. So, after some searching, I opted for a 2 pot Brembo of a KTM dirtbike, and was able to score the entire front brake setup, from master to staineless steel brake line to caliper for $40 shipped off of ebay.
But the fact that I'm building my own girder front end leaves me open to a plethora of options. I'm still running a factory xs650 front hub, so I need a rotor with the same bolt pattern, but with less offset, as the girder I'm building will only have 5" between the legs... Not enough room for the factory rotor. Plus, let's be honest, even drilled and powdercoated the factory rotor is hideous.
I'm planning to go with one of the 320mm rotors off a Ducati M900, as soon as I can find one reasonably priced and in good shape.
Because I won't have a whole lot of room behind the rotor, I couldn't go with a nice 4 piston Brembo like the one Pandemonium offers in their kit. They're just too fat on the back end. So, after some searching, I opted for a 2 pot Brembo of a KTM dirtbike, and was able to score the entire front brake setup, from master to staineless steel brake line to caliper for $40 shipped off of ebay.
