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  2. Is this cylinder damage? TY 250 A

    My cylinder is already sent out for repairs, but I will definitely be cleaning the hell out of the tail pipes. And lubing all the parts well with 2 stroke oil on re-assembly The pipes were clogged to some degree.I haven't got around to burning out the pipes yet, but that will happen soon.
  3. Is this cylinder damage? TY 250 A

    100% agree and I won't be running like that from now on. Point well taken. But the bore is at the outer limits with this stock piston. Time for plan B.
  4. Is this cylinder damage? TY 250 A

    Feetupfun and guys, Well, yes if I was close to anyone that could bore a cylinder I would walk it in there and have them tell me what piston to order, Don't have that option. And I want the shop to fit the new bore to the new piston, not the other way around. It's a whole new can of worms to me. They have to bore until the cylinder wall cleans up plus enough for clearances on the next size piston that is available. Nobody knows at what dimension that is going to happen until they start making chips. I don't know if they can do all that in one setup. I would not want to try it without having the new pistons in my hand to measure. Even then it would be a guess the first time. Tough job to get it right. I am not friends with Millenium Technologies in any way. If it turns out that they let me down, I will be the first one to let you guys all know it. If they do a fine job, then that too will be widely known on here. If the other guy that had the Nikasil work done on his bike would like to comment on his experience (who ever that was) I would be very grateful to hear all about it. Wish me luck!
  5. Age certificate for Montesa

    VMCC. Any make......... DVLA approved. https://vmcc.net/Library-and-DVLA-Forms
  6. Parts interchange

    Thanks everyone, I really appreciate the outpouring of help. I was contacted by Tim Weaver so I am now headed in the right direction. While this is my first Bultaco engine build, I have rebuilt a Triumph T150 engine and a Honda CL77 and CB550 engine. The Bultaco unit appears to be much simpler than those so I should be ok. Thanks again for the posts and pictures,they will come in handy. Ron
  7. 1976 TY175 frame bracket reference needed.

    Got it running this weekend! New headlight, fork dust boots, fuel petcock and lines, and air filter. Rebuilt the carb, serviced the front forks, cleaned and derusted the fuel tank, cleaned the frame, put the original seat back on, changed the oil, and repaired the broken muffler mount. The headlight cage is missing, my dad added an extra chamber to the muffler, and she has some battle scars. I rode it back in high school and dad used it for hunting and irrigating. I might ride it off road now and again but it's satisfying to hear it run again. Thanks for the help with the muffler mount.
  8. Hi, my Montesa 123 is somewhere around 1972 in age... does anyone know where I can get a certificate of age so that I can get an age related plate. I don't think there is an owners club.
  9. Radiator fan replacement help

    Hi phil do you think the fan is as noisy as before, I thought there was something special with the ossa fan becuase thay seem louder than other brands of bikes. Thought they had more rpm to pull air from in front of the gas tank. Oh well good to know you can still get a fan. Hope it cools as well. Cheers kim
  10. New to this Forum

    Welcome, baurespdx! Got any more classics?
  11. 16 motor

    Would it make any difference if the end plate with the brushes in was put back 180 degrees out from the outer motor housing?
  12. We are running our charity trial on bank holiday Monday the 27th. At Ayford farm near Marshfield. 11am start,there will be a catering van onsite. Brilliant venue,all different sections to last year. All Pre65 classes, plus twinshocks. NO mono's. Three routes. The venue will be signposted with red arrows from the A420 at Marshfield,please come along and join us,all proceeds will go to the Wiltshire Air Ambulance. Enter on the day. https://joncvsv8.wixsite.com/ashwicke
  13. Is it just me?

    TBH, IMHO, speaking personally, I'm happy enough to fork out for a weekend ticket to see Bou, Ragga, Dabill and the rest. I reckon they're probably worth it. I've heard that some continental EU countries have slightly higher taxes than we have here - perhaps that has something to do with it...?
  14. Improving Fork Action.

    I think so, I've just riden a 2 day event over here in Australia on what we refer to as 'C' grade lines and I quite liked the fork action, much better than anything previously and I'm happy enough to leave it alone now, running 7.5wt at 175cc per leg (basically just enough to cover bottom of springs), about 2.75 bar per leg, combination of 1x hard spring and 1x medium spring for 90 kg me. The only issue I encountered was the supplied 50mm alloy spacer was far too long to achieve the desired 28mm between top of fork tube and underside of fork cap, I solved this by re-using the adjustable magicals pre-load adjuster that I was pulling out. Some pics attached that may explain what I'm trying to say.
  15. New to this Forum

    Hi and welcome. Try here, https://clasicaslegendarias.com/fichas-y-manuales-de-montesa-cota/ You might find something of use to you. Phil
  16. Is this cylinder damage? TY 250 A

    About noise, I had just rebuild a D model, on start up it was crazy noisy. Lucky for me, I always use a lot of 2 stroke oil when I reassemble a cylinder. I noticed that the baffle ( the last piece of the exhaust ) was not '' smocking '' very much, but most of the smoke came from the joint between the muffler and the baffle, cleaned it and voila, normal sound Guy
  17. Is this cylinder damage? TY 250 A

    When you ride with throttle shut you restrict petroil mix from the piston and hey presto you get piston nipping and score lines on the piston skirt. The porting photos look like there may have been a weld repair done and then a clean up. The honing marks look a bit course from the photo and what appears to be cleaning rag fluff. The port itself would benefit from a gentle clean up or smoothing.
  18. PECO 200 SWM Teardown

    I promised an update when Id measured the stroke, AND .... its a std 125 crank with stroke of 54mm , meaning a swept volume of 171cc. Rebuild is on hold , I bought an old 280 ..... but will restart in 2019....
  19. Parts interchange

    Here’s a few tips that may help you. Take photos of what you have for reference later or when sourcing parts. Spend some time just looking at and studying pictures/videos of Bultacos and the detail. Get familiar with the model types, you will find that some owners have altered their bikes quite a bit so try to stay with the more authentic builds. Get to notice the frame rail differences as the factory modified and then introduced these changes onto production bikes. Photos of works riders and their bikes can be invaluable when assessing correctness of parts to a model. Now put the frame and cycle parts in separate areas or on shelves but keep them apart. For example front wheel and brake in one location, rear wheel etc in another, frame somewhere else and chain and sprockets in a box. I always start with the engine first, break this down into cylinder, head and piston and store away, now you can strip the engine. If you have not taken an engine apart before, get an old moped engine or similar and practice on that first. A manual is invaluable a Clymer is more superior than Haynes but both are useful. The crankcase halves cab be troublesome to spit but everyone has there own ways to do this. I thoroughly recommend that you watch some of the videos on YouTube for Bultaco, the Spanish ones are good some are crap and not all of the methods used are acceptable so be aware. When you split the engine cases some will say you must use heat on the main bearings, to release them from the cases whereas others including me use other ways....🤔 The gearbox is quite straight forward, but there are booby traps with the selector forks and a ship that goes on the kickstart shaft. Some of the breather holes made at the factory are in some daft places and when you locate these you may be surprised. You will get no end of help from the members on this site and the parts suppliers in the UK are excellent. A few photos to help🙂👍
  20. M49 rear wheel spindle reassembly

    Wheel spindle enters swing arm and brake plate from drive side. No spacer between brake plate and swing arm lug. Non drive side should be speedo drive (if fitted) spacer and additional thin spacer if no speedo or replacement double shouldered spacer. Then you have snail cam and thin washer. Some rear wheel spindles also had a thin washer on the drive side, between the spindle shoulder end and snail cam, this brings the spindle slit pin hole into line more for the castleated nut. Take the chain guard off and use a good straight edge on the rear sprocket and align the gearbox and rear wheel sprocket. Tighten spindle nut and look at exhaust where it is closest to tyre. You may need to adjust the rear silencer if the tyre rubs. It’s more important that the chain is true as this could cause serious wear to the sprocket teeth and possibly take a bit of power away from the engine. As Woody says you may have the tyre inflated too high but if the pressure was reduced to say 4 psi you might have more rubbing issues due to tyre flexing on the rim. There never has been much room for the back wheel in most Bultacos a design issue but then they tend to be slim which helps the rider. A bit of rubbing here and there will always happen when the bike is in action, you may get it all set lovely with no rubbing but after use the alignment fairies with have been busy shifting thing around for you so it all rubs on everything! If you search on this site you’ll find some tips on wheel alignment if you are the fussy sort and must have a perfect bike....and why not! But it wouldn’t be a bad thing to check front forks for correct alignment then check front to rear. 2-3 mm out is not significant ( watch me get pilloried for that comment) as it’s the chain which is important. You will not notice that small measurement when riding unless your an alignment fairy or Toni Bou. I wonder how many frames the works boys throw away after each trial because they’ve been used so hard. Last piece of advice if you are having problems still, then I would either remove the swing arm and get it on a surface plate at a local engineering company to make sure it’s not twisted. That’s fairly easy to sort with a bit of brute force or a hydraulic press. If you can’t go there then again on this site is the pics and info to help you DIY. Hope you get sorted and don’t forget you can always gain a little extra clearance on the exhaust back box by deft use of a......BIG hammer.😳🔨 Erm number plates could be covered next time 🙂👍
  21. Is this cylinder damage? TY 250 A

    The usual technique to avoid wasting money is to get the person doing the re-boring to measure the cylinder and tell you which oversize piston kit to get before you order the piston kit
  22. 16 motor

    Did you not take any photos prior to dismantling? It’ll be a novel feature having to ride sections in reverse, you could pre select whether you are on a five or maybe a clean!😁 Seriously you must have created a reverse current to flow somehow. I would go back and re check all of your work very carefully. I’ve not worked on an Osset yet but have on numerous electric motors. This may sound daft but re check battery polarity first. Then it’s down to either workshop manual or tinternet.
  23. Tech Forks Service

    The funny thing is the Formula Seal Change manual indicates to always replace the lower bush, however for me the lower bush remained in good condition, it was the upper that got damaged. Maybe best to have both on hand!
  24. New to this Forum

    Resourceful bike stand👍How high can you stack and still support the bike?
  25. Jap zap help (video)

    I'm definitely no expert at this, a bit of a beginner indeed. However as I've been working on the same skills a few things have helped me, maybe they'll help others. 1. This video talks of a "touch up". Probably what might be called a double blip more than a zap, but I consider that if I use clutch it's a zap (rightly or wrongly, I don't care - works for me). I found that rather than dropping the front wheel into the obstacle it was easier to get the timing together if I hit the obstacle on the rise. Interestingly after watching this then watching Trials GP this actually looks more like what the pro's do most of the time rather than dropping the wheel onto the obstacle. 2. I spent a bit of time doing stationary zaps on a tiny obstacle - maybe 150 - 200mm (6-8") high. Gave me the confidence to really drop the clutch and have a few revs, and also get the movement and timing dialled in a bit better without any significant consequences. I had a tiny rocky step, a large curb would be similar. 3. As the Ryan Young/Pat Smage zap video above says, I find it easier to ride into it with the clutch slipping, then drop the clutch for the zap. Heaps easier for bumbly's like me to get the timing compared to clutch out/in/out. 4. As also mentioned above, closing the throttle when dropping the clutch makes a big difference to the pop/lift. It does however rely on having enough revs up to carry the bike up to the top. Point 2. gave me the confidence to actually bring the revs up a bit closer to what's needed. Still a bit scared of too many revs, but getting better bit by bit.
  26. New to this Forum

    Hi everyone. I own a 123T, 247 and a 349. Do any of you own any cool or rare factory or dealership documents or manuals regarding a model I have. I would love to learn more about the bikes. Below is a photo of the 247 i am restoring now.
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