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Serious Black

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Everything posted by Serious Black

  1. Over the last year-and-a-bit I built up a 650 Ural with all the info I've learned since I started playing with these infernal machines in 2002. This was to be the last....the one that would keep me going for the next 100 years. Life, what happens when you are making other plans - J Lennon. And then I'm "invited" to buy a 750. Electric start (for my now geriatric knees) and ALL the extras. All for a price impossible to refuse. So here we go again. Don't know that much about the 750 so I'll be in here a bit more often no doubt. In a way it's a pity as the 650 is turning out to be a very sweet bike with a decent turn of speed. Mikuni TM28, Chang Jiang pistons and a special exhaust helped out. The 750 needs a new exhaust so I'll be cobling up a similar one for it. Carbs will remain CVK32 for the moment while I see if they are any good. The heads will get my usual magic. I don't like the look of the air filter so that may get junked and replaced with a Dnepr one. Seen this done and it looked quite neat with a straighter run at the carbs and better foot clearance. The electrics will get an overhaul and simplification. Hopefully this will be the last one. The 650 will soon be up for sale but I'm having far too much fun in the snow here at the moment so I'll add "eventually". And it's called Viggo!
  2. If you want accuracy then it's easy enough to rig up a bicycle speedo. Some of them even go up to 200mph!
  3. 0w40 motor oil makes good light machine oil! Great for lubing bowden cable.
  4. If you want to keep the points Boyer also make a box that continues to use the points (although you HAVE TO disconnect the capacitor). I've used them and they work very well. You get the "advantage" of an easy swap back to points should there be a problem.
  5. I'm coming round to the idea that the Sovek ignition may not like the coils I use. Possibly too low resistance. I've been using coils in the 3 - 3.5ohm range and opening the plugs up to 1mm.
  6. I'm not a great fan of Sovek ignitions these days but that doesn't sound like the usual problem with them. Did you use a new coil or keep the points one? It's usually termed the "dog " coil for obvious reasons and is about as good at sparks as one. Used to fit Harley 5 ohm coils then went to 3.5ohm or Honda coils. Lately after some ignition failure I've taken a closer look at coil primary resistance. These days I use Boyer Brandsen ignitions meant for Norton Comandos. The maths tell me to use a 4ohm coil with the regulator I'm using. Kawaski coil fit the bill. I'm going to look harder at coils for Sovek ignitions as the ones supplied vary wildly in resistance, some being very low. Personally, If I had your bike I'd look at new rings or Chinese pistons. There are excellent rings available from Poland. Avoid the Ukranian ones. Russian one are so-so.
  7. The magnetic cup inside the speedo and the spring it drags against have production tolerances.
  8. Nah, lapping the petcock is the traditional way of fixing it.
  9. Can I recommend modern carburetors? Makes a huge difference to both power and economy. You need all the help you can get with 2-wheel drive. Hope you don't use 75w140 gearbox oil.
  10. My mate just had one die. It would cough and fart and eventually die. Wait 5 minutes and it would start, run fine for a while and then repeat the whole process. The power transistor seems to be failing open circuit. It took the coil with it. He's just ordered a Boyer system and we are going to go with that. I have a box with 4 dead Russian systems. No box for dead boyer so far.
  11. You should deburr the ends of the brass stackpipe. Often they are crimped over by the cutting tool. I also chase through the body with a drill when the tap is in the open and reserve position as the tap often isn't aligned.
  12. Have you got any details on that 2CV centre box. Never heard of that one.
  13. I think for 2 up with a standard engine I would leave the box as standard, especially if you have a lot of kit and ride in the mountains. If you change the gears then I'd recommend an export type exhaust (the one that has 2 silencers and a balance pipe) and a set of non-Russian carbs to help you along. Personally I think a kardan with "solo" 3.98/1 gearing would be better, especially if you can pick up a spare kardan as they are quicker to change than the gearbox and it could give you the option of better gearing for solo tours.
  14. Better pistons can be found on Aliexpress and Ebay. Look for the 3 ring type for Chang Jiang CJ750. Not expensive and faaaaaaaar better than the originals. Drastically reduced oil consumption.
  15. TIPS FOR A COOLER RUNNING ENGINE Next time you have the cylinder of do a gas flow job on the ports.....don't worry you will not make them worse than they are! There are a lot of sharp edge that act as fins to soke heat into the engine. The "valve guide boss" can be shortened quite a lot. If you have a lot of valve rock get the guide holes Klined and seats recut. A light (c 3mm) radius on the top of the cylinder at the combustion chamber edge helps spent gasses on their way to the exhaust port too. Ignition timing. Not many know that the fully retarded stop can be adjusted. This should be set so that the manual retard is somewhere between 5 & 10 before TDC. I set my advanced and then back it off until it stops kicking me back! I can't remember off the top of my head what the advanced timing is in degrees but in millimeters it is 9.6mm before TDC. I have a piece of 10mm rod I poke in the plug hole that is bent to be parallel with the top of the piston when it traps against the cylinder head that I use for setting the timing. This accounts for the head gasket and a little bit of retard to account for modern unleaded fuel. Fitting Russian electronic ignition with it's built in advance curve helps cool things too.
  16. Straight out of the box. I'll post settings once we get a chance to do some testing but that will take a couple of months due to weather, covid and the time of year. Bjorns bike continues to run well with easy starting compared to the K65s he was using.
  17. I got sent these instead of the VM28 Mikunis I ordered. No impressed and gave them away without trying them. The TM28s I just bought, well, another story entirely 🙂
  18. We have alrdeady fitted a set to Bjorn's Ural. This was a good running bike that I could keep up with on my hotted K750 before we stuck the TM28s. Even without fine tuning it left me in the dust. They aren't that expensive on Aliexpress and are well made. Looking forward to getting my Ural on the road with these fitted.
  19. We are in the process of trying this on a couple of bikes. So far the results are good straight out of the box. We are going to need to fine tune the bikes for sure. Anybody done this and what sort of jets did you end up with?
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