WELSH FLAT TRACK REVIVAL

If it's a custom wheel, it might still be worth checking what sprockets are available?

If that's a Talon hub or suchlike, there's probably a wide range of sprockets.
 
Currently 17/40! as Jim's eagle eye spotted. Yep the front is a bit on the light side when you crack it open.
Looks like you have a custom rear wheel so I'm not sure a stock 650 sprocket will fit. Here's some dimensions you can check .....

full


If you put the stock size jets back in your carbs, I'm pretty sure you'll need to do some re-jetting with your mods (pods and pipes). The BS34s are borderline too lean right from the factory on a totally stock bike.

Thanks 5T. You are correct the wheels are custom (Like most of the bike except frame and motor) Husqvarna hubs and alloy rims. I just need to find a suitable sprocket combo that will deliver ‘normal’ road riding abilities; as Raymond describes.
 
That big sprocket is great for riding in congested areas with low speed limits.

Yes you are correct Marty. And if I were just a town rider I could live with it and terrorise the biking ‘You’ff’ of today. (That’s ‘youth’ if you are not down with the kids speech). That’s ‘so sick’ it’s real.
 
Apparently ‘sick’ means good. And so does ‘Peng’ here in Blighty.
 
Yes, finding a small enough rear sprocket can be a problem when using rear wheels from other bikes. The 650 runs rather small diameter rear sprockets with a tooth count in the low 30's. Most other bikes use sprockets in the 40's.
 
....the wheels are custom (Like most of the bike except frame and motor) Husqvarna hubs and alloy rims.
Not knowing the PO's abilities, I'd suggest checking the alignment between the front and rear sprocket to make sure he shimmed the wheel correctly.
Would save the aggravation of premature wear on new sprockets and chains down the road.
 
Not knowing the PO's abilities, I'd suggest checking the alignment between the front and rear sprocket to make sure he shimmed the wheel correctly.
Would save the aggravation of premature wear on new sprockets and chains down the road.

Thanks for the tip Jim.
I did run some straight lines down the drive chain alignment. All seems good.
For me that is a normal check. I run old school triple front rings to multi rear cogs on my bicycles, and with thin chains it’s essential to have good alignment.
 
As mentioned, eliminate the Reserve Lighting Unit, it's not needed. But it will require a jumper wire in it's place, details are here .....

http://www.excess650.co.uk/tips & tricks.htm

Looks like the P.O. hacked yours up anyway, cutting the mount tabs off (and on the starter safety relay too). Are those two components just laying loose under the seat? I guess the guy did make it pretty on the outside, not so much in the hidden areas, lol.
 
Lighting Tip From 5T

Hi 5T not sure this is on the right thread?
But helpful anyway,I will do that today and post in 'What Have You Done...." thread. :hump:
 
As mentioned, eliminate the Reserve Lighting Unit, it's not needed. But it will require a jumper wire in it's place, details are here .....

http://www.excess650.co.uk/tips & tricks.htm

Looks like the P.O. hacked yours up anyway, cutting the mount tabs off (and on the starter safety relay too). Are those two components just laying loose under the seat? I guess the guy did make it pretty on the outside, not so much in the hidden areas, lol.

Sorry 5T I think you were picking up from Raymond a #41 post.
 

REAR-SET BACKS

REAR SETS:

As mentioned earlier in post #48 & #56 the rear-sets were and are still giving me teething issues. Gear selection was a problem that needed some sorting.

After limping back to the Bat Cave I dismantled the left hand rear-set and investigated the problems. A steel 4mm bolt had stripped out the threads in the alloy actuating arm; it was probably strong enough for a modern day race bike with a slick gearbox, but not man enough for the agricultural box of the XS650. The images below show the 'get me home' repair:
GET HOME REPAIR 1.jpeg GET HOME REPAIR 2.jpeg
I used an ill fitting machine screw and a few nuts to hold it together. It worked to a fashion, but 'slop' made the gear changes rather clunky!

I put the actuation part into the pillar drill and drilled out to 6 mm. Then I tapped a thread to take a stainless steel Allen headed bolt; this then protruded enough to use a nylon insert lock nut on the back side. I think that will sort the issue.
ALLEN BOLT REPAIR 1.JPEG NYLOCK NUT.JPEG
The final gear issue is the angle of the actual gear lever. It points down at too much of an angle, making for an un-natural and awkward foot position especially when changing up. There isn't enough available movement with the stock adjustments; so I will need to shorten the rose jointed actuation tube, tap the end and reinsert the rose joint. This should bring the lever up to a more horizontal and comfortable position.
InkedLEVER_LI.jpg

Whilst there I also chased out all the other threaded components and lubricated the moving parts. Gear changes are now far more precise and smoother; just the lever arm position to sort now and all will be well.
 
Congrats, Adam, you're into the fettling phase of owning & riding now.

You'll need a test ride to check the slop is reduced. And after the actuating rod is shortened, you'll need test rides to get the lever position correct.

As if anybody ever needed any excuse to get out on the bike . . .
 
The short lever attached to the shift shaft is probably also contributing to the stiff shifting. Maybe you can acquire an old stock lever and make a new longer one. Just another inch or so longer would probably help a lot.
 
But truth be told, I don't think you're going to be able to raise the shift lever much before that adjustable rod hits the footpeg bracket, unless you lengthen the front lever. Heck, you may even have to lengthen the rear as well.
 
But truth be told, I don't think you're going to be able to raise the shift lever much before that adjustable rod hits the footpeg bracket, unless you lengthen the front lever. Heck, you may even have to lengthen the rear as well.
Agreed - to me it looks like its the orientation of the lever to its crank that need to be altered which would allow more adjustment of the rod.
 
NEW DEVELOPMENTS - FINAL DRIVE / CARB FLOATS / WIRING LOOM

FINAL DRIVE - GEAR LINKAGE:

I only made two rides this season on this new to me machine. Both attempts to deliver the images for the 2022 calendar.
On the first ride the rear-set gear linkage failed by sheering a stupidly small bolt; a cobbled together roadside repair got me home.
The ride did show up an un-ergonomic position of the gear lever, mentioned in posts above. The standard adjustments did not allow enough range to alter that position so I decided to investigate a solution. Initially a shortened connecting rod would raise the lever; but not without interference with the mounting plate. A longer arm on the shift selector was also a possibility.
REAR SET CONFLICT.jpg

Anyhow I decided to remove the whole unit and investigate further.
Low and behold, this has obviously been an issue for a PO who has attempted some corrective repair and failed badly.
IMG_1148.JPEG IMG_1151.JPEG
The backside of the plate has been butchered to try an allow the rose joint on the connecting rod some vertical clearance.
This has not been done with any shop tools and is a total mess. Further investigation shows the bearings are also mashed in the spindle housing.
Also there is wear causing slop in the leaver 'mech' interface.

I am not happy with the general mess discovered; and the quality of the alloy used is pretty poor too.
I have resolved to buy a new pair of rear-sets that are bespoke to the XS650. More later.

FINAL DRIVE - REAR HUB & SPROCKET:
The final drive gearing is also a problem on the highway. It currently runs with 17 Front / 40 Rear! This is great around town, with good wheelie potential; but she runs out of puff above 50.MPH; and with the thinly padded seat my butt is getting a bigger workout that George Michael in a rent boy toilet!!
I have looked at a few options as suggested by Raymond and a few others. The real problem is the Husqvarna Off Road Hub will not permit a sprocket much less than 38 teeth. The mounting holes are too near the perimeter of the sprocket / hub location.
IMG_1146.JPEG IMG_1147.JPEG
My solution is to source / buy a new hub allowing me to retain rear disc brake operation

CARBURETOR ISSUES:
I had fully cleaned and rebuilt the carbs prior to going out on the bike; and got her running really well for the first ride. All was going well until the rear-set issue; but as I hobbled back home the engine started to miss fire. She then dropped onto one cylinder intermittently; offering more gas did not help.
Eventually she cut out. After a minute to check things visually, no leaks were found or loose wires, she started up no problem. Off we go and after a few hundred yards the same symptoms. This happened a few times over. It felt like fuel starvation to me. Again she started up and then ran fine back to the shop.

I thought things through my mind and recalled an insignificant issue during the carb rebuild. On removing the carb float pins they they were difficult and a little resistant to move; the left carb in particular. The rebuild kits do no supply new pins so I reused the original ones after cleaning them up. The left pin was still difficult to reinsert to the posts and the float would not move freely. Some fiddling seemed to free it up and the bowls were refitted.

I removed the carbs and pulled off the bowls, and sure enough the LH float was sticking closed. It would free up with a light tap; but stick again with a few flicks up and down. I ordered new pins from Yambits and have now fitted them; reinstalled the carbs and air filters; hopefully that is the cure (Good weather will let me find out!).
IMG_1142.JPEG

Old pins on left you can see a very slight bend/ New pins on right from Yambits needed a bit of polishing.

ELECTRICAL FRANKEN-LOOM:
I have also spoken about this before. The loom is a mess to my eyes, although I have seen much worse on happily running bikes on this forum.
First thing, I had never heard of an AUXILIARY LIGHTING DEVICE before, and on forum member recommendation I unplugged it and tossed it over the horizon. It says you must then bridge some connections to retain operation of the headlights high/low beam; but mine it seems work fine regardless.
IMG_1143.JPEG IMG_1144.JPEG
Next job was to address the loom as a whole. Raymond advised me to strip it all out and start a-new. Jim convinced me, he's very persuasive, to try a Moto-Gadget M-Unit system installation. So I have now obtained all the components including: M-Unit Basic / M-Button sync lead / Blaze Handle Bar Indicators front / Blaze Pin Indicators rear / Full Loom Wiring kit. I need to decide on whether to go with the current handlebar OEM Jap switches, or get Momentary Switches from either M-Gadget or Revival in the USA (Brilliant custom builds). Revival have a much better design of switch, and Josh is extremely helpful via email; but their ordering system is a nightmare if parts are out of stock: https://revivalcycles.com/
IMG_1105.jpeg
So this is a part of the winter project. Photo will be taken before, during & after the rewire.

FINAL SOLUTIONS TO DATE:
I have ordered some kit from COGNITO MOTO in the USA (Super custom builds).
Brilliant to deal with even via email (Thanks John). Easy to order everything; even custom bespoke if you have deep pockets.
Custom XS650 Rear Hub / Custom XS650 Rear-Sets; both allowing standard size sprockets and disc brake conversion.
I will rebuild the new hub to the old rim using new spokes.
Nice air-box (Not ordered)
Check out their other parts too, they are good: https://cognitomoto.com
COGNITO 1.PNG COG HUB.PNG COG AIR BOX.PNG
So watch this space as The Welsh Flat Tracker evolves!
 
It's a shame you haven't had much use out of the XS as yet. But this is shaping up to be a good Winter rebuild and you will have a bike you can really use as intended next year.

My only caution would be to take it easy on buying things. Which I'm sure you do already. It's all to easy to rush out and buy expensive parts and either change your mind or later realise they ain't mutually compatible. As soon as you step away from stock, you're kinda on your own as far as parts suitability goes. So it's sometimes easier to go step by step. But you got a whole long Welsh Winter to amuse your self so plenty time.
 
I also had issues with ill fitting aftermarket float pivot pins (they were too tight). I ended up scrounging an original from an SR500 carb. If your new aftermarket replacements still give you issues, this is a part you can still get from Yamaha, and I recommend you do. More expensive, yes, but it will fit correctly and should solve your issues.
 
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