Ftwelder Posted October 12, 2021 Author Report Share Posted October 12, 2021 So I got the TS250 flywheel and it's the same as the original (but nicer) so I found one for a '74 RL250 and made the purchase. It's definitely thicker/bigger. The magnets look a little different so Ill tune the bike with the TS250 unit which is in much better condition than the original 185 flywheel. Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr I built the bits to attach the right side cover and put my new NJB shocks on for a test fit. Untitled by barnstormerbikes, on Flickr I started hammering a piece of sheet for the seat base and like the look so far. by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr 2 Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted October 14, 2021 Author Report Share Posted October 14, 2021 I had a few very productive hours and got the seat pan done. Also held down with a Dzus fastener. It's a little lumpy but perfectly suitable for the application. I used 1.5 mm for seat and side panels so they are very light. I took a lot of photos. Now that the big things are done I can clean up my work bench and assemble the engine. Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr 2 Quote Link to comment Share on other sites More sharing options...
htrdoug Posted October 15, 2021 Report Share Posted October 15, 2021 (edited) I would not put very much saddle on that at all,maybe a outline of one in black paint (-; I like to be able to lay the bike over in turns and have the saddle just below knee level (have no idea how tall you are) so you can get maximum lean while still having your body vertical. I lowered some foot pegs too far on a bike one time and tilting the bike over would drag on my thigh and pull my weight to the inside of the tire contact patch, it made it more difficult to accurately guide myself in turns. And oh yea, the seat pan works really well visually with the side panels! Edited October 15, 2021 by htrdoug Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted October 15, 2021 Author Report Share Posted October 15, 2021 10 hours ago, htrdoug said: I would not put very much saddle on that at all,maybe a outline of one in black paint (-; I like to be able to lay the bike over in turns and have the saddle just below knee level (have no idea how tall you are) so you can get maximum lean while still having your body vertical. I lowered some foot pegs too far on a bike one time and tilting the bike over would drag on my thigh and pull my weight to the inside of the tire contact patch, it made it more difficult to accurately guide myself in turns. And oh yea, the seat pan works really well visually with the side panels! I was thinking about using colored adhesive backed kitchen shelf paper for a saddle. That is pretty minimal! I have been weighing some of the original and what I am using and haven't made much progress weight-wise. The alloy body parts should help. The bike looks a little wide just below the saddle but the peg width is narrower than my current bike by 3" so Ill see. I am super tempted to assemble the rolling chassis at this point to see how it feels with pegs. I have been practicing leaning the bike myself and am only doing it in flatter turns right now on my stock 72 OSSA, possible because the head angle is quite slack perhaps 64 or so the steering ratio is quite slow when leaned on a hillside. I am 5'10", 165 lbs. Quote Link to comment Share on other sites More sharing options...
stevec Posted October 16, 2021 Report Share Posted October 16, 2021 (edited) On 10/15/2021 at 5:46 PM, Ftwelder said: "I was thinking about using colored adhesive backed kitchen shelf paper for a saddle." I used closed cell, adhesive backed neoprene foam sheets like these:https://www.amazon.com/Sheets-Adhesive-Neoprene-Insulation-Vibration/dp/B08P1W9QQD/ref=pd_lpo_2?pd_rd_i=B08P1W9QQD&th=1 . I went with 1/8" thick but 1/4" would work too. Easy to trim and looks the part. Edited October 17, 2021 by stevec 1 Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted October 18, 2021 Author Report Share Posted October 18, 2021 The RL flywheel is the same as the other two except for the ring pressed on the outer circumference which makes the diameter about the same as my outer cover. I ground an old crank bearing to slip in the case bore to check mounting depth with a piece of modeling clay and I have around 19mm of side clearance so Ill draw something up and get a CNC lathe guy so spin up a weight that engages the TS 250 flywheel and mounts to the puller holes and is no larger than the stock flywheel. So now we know I can add weight and also make the motor narrower. All good. Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr 2 Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted October 18, 2021 Author Report Share Posted October 18, 2021 That odd grey thing in the bottom right corner of the last image is a soft lead weight I use for a hammer on the motor internals. Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted October 19, 2021 Author Report Share Posted October 19, 2021 (edited) On 10/16/2021 at 6:20 PM, stevec said: I used closed cell, adhesive backed neoprene foam sheets like these:https://www.amazon.com/Sheets-Adhesive-Neoprene-Insulation-Vibration/dp/B08P1W9QQD/ref=pd_lpo_2?pd_rd_i=B08P1W9QQD&th=1 . I went with 1/8" thick but 1/4" would work too. Easy to trim and looks the part. That looks nice! wear a cyclist bib shorts under my pants but will probably go bareback before adding anything. I used a 3/8' thick closed cell neoprene floormat on the OSSA and it needs to be cut back.. Edited October 19, 2021 by Ftwelder Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted October 27, 2021 Author Report Share Posted October 27, 2021 I drew up a flywheel weight that should fit in the space and add some inertia. Next thing was to add a port to lube the crank bearing. I opened up the forced oiling port a bit and drilled through from the transfer port to the stock forced oiling port. I hope it works. This it the work site. Untitled by barnstormerbikes, on Flickr I drilled through to the original hole and created a funnel to guide some mix down the hole. It might work. Untitled by barnstormerbikes, on Flickr I noticed so cracks around the shifter boss. Untitled by barnstormerbikes, on Flickr Exploring a bit it looks like the shifter took a big hit. Untitled by barnstormerbikes, on Flickr I had a struggle removing the trans shaft bearing and ended up welding in a nut to attach a slide hammer. Yes. I tried the hydraulic method first. Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr I guess I have to weld a boss inside the case to support the shift shaft. 1 Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted October 27, 2021 Author Report Share Posted October 27, 2021 (edited) I used a slide hammer, not the end of the bolt. 😁 and it came right out. Edited October 27, 2021 by Ftwelder Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted October 31, 2021 Author Report Share Posted October 31, 2021 (edited) I straightened the shifter shaft and filled the worn/gouged spots with silicon bronze, filed it down and machined a new "hole" to bond in the pocket. I lost a little bit of the OD of the shaft and got lucky finding an undersized reamer in the stash and got a good fit. Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr I thought about using bronze for the bushing but it's soaking in gear oil so I passed. Untitled by barnstormerbikes, on Flickr I may have mentioned I had found another used cylinder/piston in great shape and figured now was a good time to put it into play. I made a double-wall spigot to get a good pipe seal (a good bit of work) and set out to delete the original feature in the stock cylinder. Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr I added a few layers of 4043 and hopefully didn't get any low spots. Untitled by barnstormerbikes, on Flickr Grind to taste! Untitled by barnstormerbikes, on Flickr Inching closer! Thanks for looking. Edited November 1, 2021 by Ftwelder duplicate photo 4 1 Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted November 22, 2021 Author Report Share Posted November 22, 2021 I have made more progress and thought I would share. I got the cylinder and head back from cleaning and they look pretty shiny. Ill probably need to age in dish soap get it looking better. Untitled by barnstormerbikes, on Flickr I have been trying to educate myself on the workings of the crankshaft oiling system. I have my original crank (badly rusted) and another ebay crank assembly to work with. I removed the LH bearing from the ebay crank and recovered the oil slinger which seemed be damaged though I thought I was careful. I then had to resort to extreme measures to remove the bearing from the original crank. Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr This evidence combined with the plastic seal that came on my new LH bearing (and no plastic seals in original bearing gave witness to a number of problems with the system (though it's clearly quite functional) The system takes a portion of the oil and introduces it to the intake stream (like pre-mix) and another ration is delivered to a bearing that deliverers raw oil to an exposed lower rod bearing. Once used the pure oil is flung around to various places depending on RPM and air movement. I don't see a need for any part of it if you delete all of it. I added a swail to the port wall to load the back of the bearing. I have seen this before. Ill make a new spacer to take up the end play. Untitled by barnstormerbikes, on Flickr 1 Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted November 22, 2021 Author Report Share Posted November 22, 2021 I worked on the front brake a bit. I had already relined the shoes with aggressive material and when setting the brake up ran into a few problems. The wheel dish was way off so I faced off the KDX brake plate to help solve the problem. Untitled by barnstormerbikes, on Flickr I used a longer alloy rear arm which has poor alignment with adjustment point so the housing stop will be part of the anchor arm (This one was not well designed with some misalignment at the rear hole) Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr I also made a front axle from 1045 steel with alu cap. Untitled by barnstormerbikes, on Flickr Untitled by barnstormerbikes, on Flickr Thanks for looking. I have some rim questions! 1 Quote Link to comment Share on other sites More sharing options...
Ftwelder Posted November 22, 2021 Author Report Share Posted November 22, 2021 (edited) I have three front MX rims, two are for conical so the third can't be easily used. They are all marked 1.6X21 but vary in outside width from 2.1" to 2.5" on the outside. with the narrowest one being 1.75" on the inside? What is typical? Why? Untitled by barnstormerbikes, on Flickr Edited November 22, 2021 by Ftwelder Quote Link to comment Share on other sites More sharing options...
htrdoug Posted November 22, 2021 Report Share Posted November 22, 2021 Shouldn’t the brake backing plate be on the left fork leg? Quote Link to comment Share on other sites More sharing options...
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