First XS650 Build, What to Look For

[SlowMaintenance]

More pictures of the progress. Had a real pain in the ass of a time getting this seat to mount up correctly. If anyone has used the biltwell slimline seat you might have had similar issues. The bolts for the springs mount to the seat pan at about a 45 degree angle which makes hooking them into the bungs below nearly impossible. I had to bend the front of the seat pan to flatten the angle a little bit so that I could get them reasonably placed. All in all I think it came out decently, but I'd definitely go with a different seat or different springs if I had to do it again.

Left spring

Right spring (bolt is not pushed as far right as it could be, but even so, I think I may need to dremel out the adjustable seat pan notch to allow me to mount the bolt a quarter in further right.)

Slight torsion on the springs, but this was corrected a bit by bending the front of the seat pan down to reduce the angle. (Not bent in this photo)

Seat hinge welded on

Bottom view (hard to see I know)

Current state (minus the angle of those springs, I forgot to take pics after bending the seat pan)

From here I need to...
Mount the headlight
Install a sissy bar
Mount rear fender
Mount tail light and plate to sissy bar
Install engine
Wire headlight, taillight, PMA, Key switch, E-advancer and capacitor.
Get a new petcock w/ 90 degree bend to clear engine top mount
Kick it over and see what happens

 

[SlowMaintenance]

Hey guys, another question for those of you who have used the Mikuni VM36 carb, what are you using for a throttle cable? It seems like there are so many options out there but I'm not sure if I should be looking for one with a 90 degree bend at the carb side or not. Also not sure if it needs to screw into the top of the slide or just sits flush against it. Anyone who has any info (or a link to a cable they used successfully) would be greatly appreciated.

Thank you!

 

[5twins]

I can't recommend a specific cable but I can tell you a few things. You need cable adjusters in the carb tops. That is how you sync the VMs, by adjusting cable freeplay so it matches carb to carb. The adjusters aren't part of the cable, they mount in the carb top and the cable just passes through and sits in them. I think on a stock bike, the 90° adjuster works better for clearance but with your little peanut tank, that may not be a concern. The plain straight ones may be fine. That would be good because that's what the carbs usually come with. You have to buy the 90° adjuster separate, at an extra expense.

 

[SlowMaintenance]

Got it. I'll have to do some more googling to find the adjuster portion. Sounds like a universal cable might work for this since the cable mounts in the carb under a slotted disk. Any round ball should be able to fit. Barrel end up top would be needed for the throttle.

Also, it will be a single VM36 carb so no syncing to worry about, it also helps with the clearance issue in that the carb will sit out from the frame a bit with the petcock is almost directly above it.

 

[mrtwowheel]

SM, this is what I did for that ridiculous angle of the bolts/studs under the seat.

First there is a washer, then a nut, then a thinner jam nut, spring goes on, then a washer and nut. I'll try to use a lock nut or lock washer when I put it on for good, or if there isn't room lots of lock-tite. This lets the spring go to a different angle. I'm using a bung at the bottom of the spring and bolting the spring solid to the bung. That piece of ABS plastic will have leather fringe glued to it.

Scott

 

[SlowMaintenance]

Very innovative idea here, I like it! At first I thought I had installed something incorrectly when I saw how the angle sat, but I can see now that this is a problem that plagues all builders looking for a seat with some decent kickup.

I'll probably give this a shot if I see that the springs aren't working out the way I have them set up currently.

On another note, for anyone in here who was also curious about my throttle question, I have the answer for you. Or rather, Figure8 had the answer for me and I'd like to share it with you, so be sure to thank him if you were hunting for this info.

Keep in mind, this may vary if you have very tall handlebars, but it's still a good starting place.

Throttle Cable: https://goo.gl/PQZBDY
Throttle Cable Router: https://goo.gl/2LXeDs

Please remember though, this is a setup for those running a 2-1 intake with the Mikuni VM36 carb and it works with the cheap $20 single cable emgo throttle assemblies you can find on ebay. The cable router is the 70 degree variation, but is also offered in 90 degree and 45 degree. I'm going to use the setup w/ the 70 degree as I saw the action on Figure8's and it was buttery smooth with excellent snap back. I'll post pics and a walkthrough of the install for anyone who may like to see.

Heading back to the garage tonight to weld a piece of round stock into the open hole left on the neck tube after cutting off the key lock. Not sure that I want to weld the rear fender on yet, as I'm not certain whether the wheel is aligned properly. Will bend up and weld on a headlight mount as well.

 

[SlowMaintenance]

One more question for you guys. I'm going to grab the engine and take it over to my buddy's place tonight so I can get everything put together. My question is...how much will the alignment matter when mocking up the rear fender? As you saw in the earlier pics, the rear tire on snug and secure on the rear section of the frame, but it may not be perfect sprocket to sprocket. How do you guys go about making sure that the alignment is correct? I'd hate to mock up the fender and realize afterwards that it's off and the tire needs to move.

 

[mrtwowheel]

I use this string method to check the sprocket alignment .

Place a 8-1/2" spacer between the axle plates, secure it with clamps, all-thread or what ever it takes to hold it in place. Make a mark on this spacer 3/4" from the left side axle plate. Using a nylon string, tie it off in front of the front sprocket or have someone hold it against the most forward part of the front sprocket. Stretch the string over the 8-1/2" spacer. Move the string from left to right until it barely touches the rear of the front sprocket. You have just created a line extending the outside of the front sprocket to the spacer between the plates. This line should cross the 3/4" mark that you drew on the spacer. If the string is within 1/8" of that mark.......call it perfect..... and use the washers as I said earlier. If the string is more than 1/8" or so from the mark, some adjustments should be made with the spacers/washers, and the stock adjusters may be compromised. I suggest you check this sprocket alignment, also something that should be included with instructions.

Scott

 

[SlowMaintenance]

I remember reading this but I'm embarrassed to say I don't understand what you're suggesting. I get the general concept I suppose, but when you say "tie it off in front of the front sprocket" is this a single string? Are you saying to tie it to one of the teeth and drape it over the top of the sprocket, leading back toward the spacer between the axle plates?

If I were to measure this though, it would only be to the spacer between the plates, and wouldn't necessarily measure where the wheel sat with the spacers I have in there. The front sprocket isn't the portion that moves so I'm unclear as to what we're measuring with this method.

Also, WHERE in the axle plates you put that spacer would make a huge difference on the total distance between the two measurements. Too far forward and the reading would be smaller, the reverse if further away.

Maybe you can call me at 860-670-2871 so we can chat about the procedure?

 

[fredintoon]

Hi Nick,
the transmission and rear sprockets need to be in the same plane to avoid premature chain & sprocket wear.
I'd say temporarily remove the rear axle spacer washers so the rear wheel can be moved sideways.
Then clamp a yardstick to the transmission sprocket so it goes back across the rear sprocket.
Then shuffle the rear wheel sideways until the yardstick sits squarely onto both sprockets.
Now measure the gap you'll need to fill with washers to keep the wheel right there.
Re-assemble with that exact thickness of washers in the gap and she'll be good.
BTW, I don't understand your problem about the fore and aft washer placement making a difference.
The axle plates are (or should be) parallel to each other and to the bike's centerline and
the spacing washers are on the axle. WTF?

 

[mrtwowheel]

Just like Fred said, imagine holding a straight edge against the front sprocket, just above the sprocket center. That straight edge should come to the outside of the rear sprocket.

I am doing the same thing but with a string. I'm getting the wheel out of the way just to make it easier and replacing it with a piece of wood or anything 8-1/2" long between the axle plates. I measure and make a mark on that wood 3/4" from the left axle plate. That mark is now the outside of the rear sprocket.

It works. Stretch the string, it touches the front of the front sprocket and barely the rear side of the front sprocket. The string is the straight edge to show where it lines up with the rear sprocket that is now the mark on the 8-1/2" piece.

So, how far off is the string from the mark?


Yeah, I have straight edges, I have two complete cabinet shops, I'm not going to cut up and sacrifice a good aluminum straight edge when I can pick up a piece of nylon string and do this in only seconds, and dead on accurate too.

Scott

 

[mrtwowheel]

Just like they built the Pyramids, and you don't have to be a Mason of the 33rd degree to do it either.

Next time my wheel comes off I'm going to take a picture of this. I'll be doing this check a few times more and definitely after the final welds and before the final assembly is done.

Scott

 

[mrtwowheel]

Why I remove the wheel.........If my string line errs to the inside of the rear sprocket, I want to know exactly how much that err is, I can't do that with the wheel and sprocket in the way, also I want to measure near the center of that rear sprocket, I can't do that with the wheel and sprocket in the way.

This has been fun, Scott

 

[angus67]

I used a laser from a circular saw to align my sprockets. Although, i think a piece of string would be more precise

 

[fredintoon]

- - - Yeah, I have straight edges, I have two complete cabinet shops, I'm not going to cut up and sacrifice a good aluminum straight edge when I can pick up a piece of nylon string and do this in only seconds, and dead on accurate too.
Scott

Hi Scott,
not to teach a man his own trade but I'd have thought a person with two cabinet shops could have used a table saw to cut a suitable straight lath out of a piece of scrap hardwood?

 

[mrtwowheel]

Hi Scott,
not to teach a man his own trade but I'd have thought a person with two cabinet shops could have used a table saw to cut a suitable straight lath out of a piece of scrap hardwood?

Yep, I knew that comment would come up. That custom made hardwood straight edge would be less than 3/4" wide and what, about 30"+ long. I wouldn't trust that to keep it's stability, especially in the heat and humidity that we've had lately, pine, spruce or fir would be even less stable. heat and humidity does not affect my nylon string. Besides, my Delta tablesaw is center stage serving as a workbench, covered with boxes of collected electrical parts, The Craftsman is pushed up against the wall to make room for other things.

Scott

 

[mrtwowheel]

I did use the Delta to precisely cope some bungs. Worked very well.

Scott

 

[fredintoon]

Hi Scott,
as my own workbench, table saw and even my pillar drill table are buried in seas of shit I'm well aware of the problems given by the "first available flat surface" parts storage system.
My solution is a pair of folding saw-horses and a 2' x 4' slab of 5/8" plywood that has to be cleared off and put away again after use so the car will fit in the garage and I will be spared the onslaught of my wife's wrath.
So Yeah! String is the thing!
Now back to sprocket alignment.
Besides lining up with the transmission sprocket the rear sprocket mustn't be skewed out of plane and that will happen if the chain adjusters ain't done right.
To check the rear sprocket ain't skewed you gotta do the ol' stretched string trick as part of the chain tension adjustment.

 

[mrtwowheel]

Fred, you put cars in your garage?

Yes, checking that the sprocket line is 90* to the beginning and end of the axle slots would be a good thing too, and easily compensated for. I can well envision a way to do that with string too.

Scott

 

[fredintoon]

Fred, you put cars in your garage?

Scott

Hi Scott,
no, my wife puts her car in our garage.
If your alternative was to go outdoors on Saskatchewan winter mornings to unplug the car's block heater, start it's engine, brush the snow off it's bodywork and scrape the frost off it's windows you'd make space in your garage too.
There is some leniency in Summer but I'd still rather there was room in the garage so the local teenagers couldn't slash the car's tires or smash the windows in the hope of finding stealable things inside it.