pmk

Bondy, you have several topics going regarding the paint to use on the tank, the decals and more. Curious, how bad is your tank currently? A photo would maybe offer insight. Also, are you keeping the tank the original color, or doing a color change? i have a vintage KTM also. That bike came new with a white fuel tank. The gasoline / premix causes these tanks to yellow. Some owners have decided to not go crazy, and leave the yellowing as is knowing that the plastic is saturated with volatiles that may cause adhesion problems for paint. Others though have done as you plan to do, and painted the tanks. The best solution for the KTM turns out to be, a tank skin. This is a cover of sorts, that is white plastic and molded to match the oem tank. Since no fuel contacts the tank skin, unless you spill while refueling, the bright white color remains. Search for 1981 KTM 495 fuel tank and some info should be found. if your Scorpa tank is in good condition, you might consider, and I mentioned this before, perforating the graphics to allow them to vent. Below is one tool made specifically to perforate plastic films on model airplanes. Might be worth researching. On my 73 OSSA MAR, new it had a fibreglass fuel tank. As I did the resto-mod to the bike, I installed a white Clarke plastic fuel tank. The green stripes I made from MX background material. Even with draining the fuel tank completely after each ride, storing the machine with no fuel in it, the decals still bubble. My solution, prior to each event, I spray glass cleaner onto the decal, then carefully push the bubbles out with a plastic bondo spreader. Takes 5 minutes. That said, yesterday, I peeled all the graphics off the Scorpa fuel tank, except the Scorpa logo near the fuel filler cap. Check the link below for a perforating roller. As mentioned, read about restoring the white KTM fuel tanks. Those bikes need to look really good, and with a value being what a new Scorpa costs, the owners most times want the bikes super nice. https://www.towerhobbies.com/cgi-bin/wti0001p?&I=LXHZ26&P=0

ATF can be a fine choice to use in both a fork and rear shocks, however, other times it is less than good. FWIW, in my KTM,I run Mobil 1 ATF, with great results. This is in the fork only. On the 73 OSSA MAR, as I did the rebuild, I used Mobil 1 ATF in both the forks and the Curnutt rear shocks. After a few rides, it was apparent that both ends of the MAR were overdamped. Ridable but not lively. In the forks I switched to Maxima 5 wt fork oil. They work well with that setup. The rear shocks, originally specified running Ford ATF. Consider these were state of the art in the early 70s. Keeping this short, I swapped the rear shock fluid in the Curnutts to the same Maxima 5wt. Noticeably improved, but still no spring in its step. Ultimately, I had to make changes to the pistons bleed holes to get it sorted out. All that said, use caution when going to a different fluid, it may make a drastic change, or may be fine. This link is for Peter Verdones suspension fluid info he published a long while back. Good info to keep things consistent when changing brands or viscosity of fluids. http://www.peterverdone.com/suspension-fluids/

I could be wrong, but thought the main jet was seated against a washer.

Almost all plastics will tend to have some portion of the gasoline chemistry permeate through the plastic. You can try painting, it may work well or not. In an effort to minimize decals from lifting, most longterm decals come with small holes punched in the decals to allow the decals to vent, rather than bubble.

The airboot is a TY250Z part carryover onto the Scorpa. Disregard the tab, and ensure the airboot is oriented correctly so the offset does not strain the carb and intake rubber manifold. Also, ensure you do not secure the clamps too tightly. It can crush the airbox spigot or force the airboot off the carb spigot. Either would allow unfiltered air to enter the carb. If it matters, my SY has the tab at approximately straight downward on the airbox spigot.

Proper orientation of carb slide and needle assembly details.

My bike, likely all original. Fronts are button head, m8x16, lowers are flush head, m8x16

Shortly I will measure, Yesterday was crazy and I fell asleep before checking. Check back in two hours. The exhaust mid box is a slip fit onto the head pipe. Mine was a bear to get apart as carbon had built up on the head pipe where it sits inside the mid box. Took some silicone spray so as not to trash or swell the o rings, then carefully, and patiently was able to seperate the two. Once apart, use Scotchbrite and solvent to completely remove built up carbon. Then on reassembly, I use silicone grease, also known as Di Electric grease at tne auto parts store. I also use the silicone grease for the silencer to mid box joint. Taht allows easier removal of the entire subframe with silencer still attached.

I am in the USA. Since you have the curved bash plate, later today, I can measure my own bikes front bolts for you. Yes, the number would be M8x??

Interesting, how certain are you that yours is a 2007? The 06 shows a curved bash plate while the 07 is the flat type. Also, I thought, but could be wrong, 07 was the first year of the yellow spring.

If you have a 2007 with the yellow spring on the rear, could you be kind enough to measure the springs wire diameter accurately and if possible, the springs free length. Thanks

Appears the two rear bash plate guard bolts are 08x20mm. These are different than the o8x16mm they show for earlier years. The difference being the bash guard itself. Do you have the smooth bottom bash guard with no curled edges, or is yours the curled edge style? If you do have one for a 2007, it is supposedly the non curled edge type, and takes the 20mm long rear bolts. The fronts I am not sure of. The part number does not code in the diameter and length. All four bolts use nylon locknuts. Fuel tank bolts are 05x40mm, however the proper bolts are washer heads built into the button head bolt style, and are possibly stainless, like the subframe bolts.

Wanted to add, if anyone has a SY250F or SR280; the measurement of the spring wire diameter on those may work also.

My SY has the white progressive spring. Wondering if anyone has the later year bike with the yellow spring. Need an accurate wire thickness and number of coil wraps if possible. Wanting to find a straight rate spring for mine to try.

No doubt downloading manuals and parts catalogs is worthwhile. Besides the one you linked, I also downloaded pretty much all the years they offered the SY250R. As for the carb being assembled wrong, the illustration may have helped the previous person that assembled it, then again, maybe not.

I revived this old topic on account of its releavance. First off, the info from peterb is incorrect since the SY250R stock TK carb is not the style cable retainer he described. The info straycollie got from Birketts is accurate and correct. There should be a small washer with both a tang and dimple. The tang is inserted into the applicable hole in the slide. The dimple serves to engage the opening in the needle clip, preventing the needle from rotating during engine operation, provided the clip is snug in the needle groove. Here is my main reason to bring this forward. My 2005 SY250R was purchased several months ago. I removed the engine and suspension, rebuilding the bike as I assembled it. I did disassemble the carb, cleaned, and reassembled it. Upon riding the bike, the jetting was always a bit rich. Obtaining pilot jets and a nozzle is diffiucult in the USA, though I tried to order them, planning to rejet the carb to get smoother running. Without all the jets I desired, my choice became to adjust the needle clip position. I had not removed the needle during the major teardown. Upon removing the carb slide needle retainer, I noticed someone previously installed the tanged clip under the needles clip, thereby raising the needle, causing the rich jetting. In an effort to see a change to less rich engine running, I installed the clip in needle slot 2, and correctly assembled the tang washer position. With just some test riding around the yard, the engine runs very clean, and no longer rich. Next I plan to raise the needle one clip groove to the middle, as it was when assembled incorrectly, to verify that setting. In simple terms, if the tang washer is installed incorrectly, and positioned under the needle clip, vs correctly which is on top of the needle clip, the needle is raised the thickness of the tang washer (and dimple), or raised about slightly more than a clip position. Assembly sequence, needle with clip into slide, tang washer on top of needle, needle retainer / cable holder with spring holder for needle next, secured with screws. Then slowly rotate needle and clip until you feel the gap in the clip engage the dimple.

Or leaking electricity and magnetism from the flywheel side...

Ironically, this exact process was suggested yesterday to me by a long time rider. I have called him a couple times to get advice simply because he is a good rider and experienced. Also, he is the one I purchased the SY from, not that he rode it, but rather knew the entire history of it, and swapped it as a partial payment on another bike he was selling. So far, I like the SY, just a few items to sort out. The clutch grabbiness being one. Being in the USA, finding a clutch cover gasket is not simply a run out and get it sale. Been inquiring with a UK Yamaha dealer for that gasket and several other parts. Plan to email Birketts in a moment.

Yes, originally, the original setup was with the nut on the opposite side of the arm. This mod is pretty much to ensure the clutch slave cylinder does not bottom out at clutch disengagement, causing damage to the slave cylinder. Overall, the clutch arm position is a based on the clutch itself, as in wear of the friction plates, pressure plate and inner basket. Those items justify where the clutch pushrod sets with the clutch engaged and slack removed. Moving the nut to the opposite side of the arm stuffs the slave piston slightly further into the bore, preventing bottoming at when the lever is drawn to the grip. Since most of the clutch arm and slave movement remains very similar regardless of where the nut positions, I doubt there is any gains there, other than I previously mentioned. As for the oil, I used Shell Rotella T4 15w40. Based on what Yamaha recommended (10w30), and the good results Rekluse seems to have in the auto clutches, plus on the advice of other riders suggesting avoiding synthetics. http://rotella.shell.com/products/rotella-triple-protection.html

No worries, the photo is of my SY and how I set it up just recently. Clutch is bled properly, and adjusted properly. The clutch releases absolutely fine. The clutch engagement is grabby, going from smooth to right now with little lever movement. As far as the clutch mechanism, mechanically it works well releasing and engaging, just is grabby as it finds that point.

Nut is installed on the adjuster pin, so nut is closest to the hydraulic slave cylinder not on the outside of the clutch arm.

I did a search and read what has been written, seems it is not uncommon for riders, even well experienced riders, to find the SY clutch kind of grabby or on. / off. Without condemning the bike, engine or fact they adapted a hydraulic clutch setup onto a cable design setup, has anyone found a means to smooth the engagement of the clutch, especially as the lever just begins engagement. FWIW, my own bike, the clutch is properly bled, and does have the required freeplay. It is just a bit more grabby than smooth. Open to ideas, no doubt will hear about buying a new bike, but ideas on making modifications would be better.

Not exactly the beauty queen of protection, but certainly should beat that beauty queen up when the going gets tough.

Bondy, any luck finding the carbon or other protectors for the cases? Photos if you did would be nice.

I recently went through the details of my own SY250r. This was my answer to carb hoses and routing.