pmk

I guess being old, and long time rider and mechanic, but still able to make a mistake could have had the clip installed wrong. On another website it was suggested to install the master link with the clip towards the tire to lessen tne chances of a rock knocking it off. Seems logical, so an easy swap. As for those rims...two things, first they are a brushed and anodized finish that is not shiny. Yes they are dirty, this bike is ridden, but does get washed, just not so much bright polished to be as pretty as the OSSA MAR.

Then it would be prone to popping off. Zoom in on the photo. It is installed correctly.

Minor change, but does make things easier.

Ensure the chain is properly tensioned and keep an eye on the exhaust midbox. You might see chain marks on the exhaust.

You might not easily find a 40t with the countersunk holes. My recent search only found oem 38t with countersunk holes. Ultimately, I bought a new old stock and modified it to fit properly. If you are also installing a new chain, do your homework, as some chains are physically larger than others, and will require attention on the tensioner block and possibly the center exhaust box.

I spoke with Mike Komer while seeing if his shop had a Talon rear sprocket with added teeth from stock. His recommendation was 40 or 41 being what he rode back when these bikes were current. Mine at 10:40 seems good so far. Better low speed control and less abrupt launch. 41 might work, but suspect 42 would have difficulty keeping the front wheel floated as the engine winds up quickly.

10:38 is stock. I just went to 10:40.

Well that is interesting. And yes, the Scorpa cylinder does have a sealed bolt type plug in the hole the linked TYZ photo has the decompression setup. Let me see if Paul from the Hell Team in Australia replies to my email. Possibly that other automatic decompressor from the chain saw would screw into that already existing port, and make this thing even easier to fire up. Thanks for finding and sharing that link.

Yes, I have spoken to Mike before. Actually, this bike I have was imported through his shop. Just to be clear, the bike and engine are fine, yes it has a long kick start lever and starts easily when cold or hot. The point I want to emphasize is not that it starts difficultly, but rather there is a lot of compression to kick through, even when moving the kickstart by hand. I asked about the bleed hole wondering if anyone had done a mod like this before, simply so if the bike stalled while in a section, it would take less effort to refire the engine. Currently, it takes a dedicated kick to start and while I have not tried to bump start it, I am not even sure that could be done vs skidding to a stop. If the later years and non UK models are known to have a lighter flywheel, and some people have mentioned the advanced timing and lighter flywheel can combine to have the engine stall without warning, it is not uncommon to reduce compression slightly with a lighter flywheel. I need to make a call or ask those that may know more questions. Actually, it is a fine bike as is for entry level like myself, just wanting to sort out a few quirks it does occasionally, like stalling, but not often.

new handlebars, triple clamps, flywheels, rear fenders, head lights, forks, rear shocks, middle exhaust pipes, silencers, sticker kits, cylinder head volumes, foot rest positions. Want to add, without much effort, it is apparent there was evolution to these SY250 machines. There were certainly changes in the first years with the forks and triple clamps and possibly frame improvements. The list above for 2007, seems the release of the 2007SY250F four stroke saw some of those items make it onto the two stroke Word was the bars and triple clamps now had multiple mounting options for bar location. Supposedly the 2 stroke got the lighter flywheel countries outside the UK had been getting all along. In 07 the forks swapped from Paioli to Marzocchi. The 2007 SY250R got a straight rate rear spring and I assume valving changes inside the shock. The head was changed and not sure where they repositioned the footpegs, but it says they did. Most other items are paint and graphics changes.

The actual brochure I had saved did not want to open easily, but this list is what was changed for the 2006 to 2007 model. I did check the parts books, in 2007 the part number for the head was changed from previous years, while the long ride version retained the previous years same part number. This list was pulled from an internet page stating these were the changes to the long ride, but that seems like the list I had previously mentioned in regards to the SY250 racing. Note the near bottom and it does indicate a change to cylinder head volumes. Possibly, they reduced the compression to work better with the lighter flywheel. I honestly do not know. new handlebars, triple clamps, flywheels, rear fenders, head lights, forks, rear shocks, middle exhaust pipes, silencers, sticker kits, cylinder head volumes, foot rest positions.

Firing up the laptop, pretty certain I saved the sales brochure that indicates increased compression, I think. If not it is something that was posted on the vast internet.

Interesting, mine takes a pretty good effort more than slippers would allow. I have read the later year versions did have increased compression. Maybe the USA or should more correctly say, the non UK versions have the higher compression that Scorpa advertised in the later models. I say this because those later models, in the sales brochure also indicated the lighter flywheel. Thanks for the reply. Need to do more homework now regarding how they increased compression.

Actually guys, it does start well. Timing is advanced. Most people consider these a high compression motor, and honestly, it requires a pretty good push of the kickstart to crank the motor through. No plans to add a decompression device. Just wanted to get it to spin slightly easier, so if it were to stall, it could possibly refired before putting a foot down. As is, it would be difficult. As I mentioned, some cylinders have a small bleed hole into the exhaust port. Drops the cranking pressure a bit for easy starting and is a non issue while running. Other times the manufacturers have cut key slots extending the port toward the head. Just another way to lessen cranking effort.

Agree, but Bondy does have about half a million very recent posts about that old Yamaha engine in the French chassis. Besides, is a modern Scorpa still truly a Scorpa, or rather a Sherco with different paint? He certainly did not ask about Shercos or their granddads, the Bultaco.

The drain on the Scorpa SY250 he is referencing, is nothing like a standard case bolt. Case bolts are typical Allen head style, while the drain is a hex head bolt style with built in flange to help seal the copper washer.

Agree on the manually operated cable actuated compression release, they would work too good for what I am suggesting. My 73 OSSA MAR has the cable operated type in the second spark plug hole. Some bikes though have a bleed hole, and it reduces cranking pressure to get it started. No mechanicl device or anything to operate, simply kick and go.

SY250r, has anyone made a compression release to let the engine be started easier. When I say made, some of the vintage open class MX machines came from the factory with a small hole drilled above the exhaust port. This bled off a portion of the compression pressure while kickstarting, but was a non issue while the engine was running. Granted the TY250Z engine used in the Scorpa starts pretty easily, but certainly has a bit of compression to kick through.

I believe, and can check next time I drain the oil, that is a second drain plug. If the Scorpa had a left side kickstand, you could remove that drain while on the kickstand, rather than use the lower one where the bike must be vertical to drain the oil. The parts manual shows it simply as a straight bolt / plug. No special detent or anything, just a plug.

After some tinkering around with engine tuning, and I won’t post my actual jetting since it can be varied for other parts of the world, I want to mention that the needle clip groove position is quite sensitive to jetting on the SY250r. I found that running in the middle groove, while not bad, was rich. The exhaust showed signs of spooge and a wet tailpipe. Also, the engine could be felt to be rich when riding. Not blubbering rich, just slightly rich and it showed in the transition from pilot jet to needle. I tested the next clip groove leaner. The engine ran clean, accelerated ok, but had a slightly soft exhaust note and soft accelleration. Also, you could faintly here the engine wanting to ping and ever so hinted at surging. To work within the two settings, I fabricated a 1/4 mm thick shim to provide a mid point between grooves. These are also easily purchased, but I opted to punch one from shim material rather than wait. The shim was installed under the clip, raising the needle 1/2 a groove. Essentially place the needle position at clip groove 2.5. In this setting, the engine runs absolutely clean, but is now crisp with a good exhaust note. No pinging or surging is there currently. The engine accellerates strong with no hesitations. Possibly the TK carb, the 26mm carb size, and the engine exhaust combo have made it this fine to adjust. I do not have any optional needle jet sizes, so possibly the next leaner brass needle jet is sized to be 1/2 steps of the clip groove. But I am not sure for a TK, plus the needle jet would need to have a trip from a Japan warehouse, to a UK Yamaha dealer, then sent to me in tne USA. Simply sharing.

Capacitor, the round cylinder shaped item, black in color with a rubber sleeve it sits within. Mounts onto the subframe tab. On my SY the subframe screw was in hard contact with the capacitor.

I spent a bunch of time on positioning the stuff. Assumed my bike was as delivered, and if so, I certainly changed it for an easier fit. Be sure to check and relocate the capacitor.

Bondy, you are not wrong or crazy about the CDI. My best advice, go to the ADVRider website, in the trials section I started a SY250R topic. In that topic I posted all sorts of photos, including repositioning all the electrics next to the carb. If you look close, the capacitor mount is wrong and the subframe bolt will be trashing the capacitor. Thes SY250R are a decent machine, but some stuff is really cobby unless you sort it out.

One of the guys that restored his KTM tank, photos and some info. http://www.ktm495.mxbikes.com/index.htm?REF=other37777.htm

Tank Skin, for reference only as they are not available for the Scorpa. https://www.dcvmx.com/xcart/product.php?productid=17991