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  2. Bantam - 4 speed into 3 speed look-a-like?

    I’m with you now. I assumed as there was no points cover on the clutch side, the c/shaft must be reversed to have them on the drive side as per 3 speeder. But, as you say with electronic ignition it just needs a trigger on one side of the crank to work. Stupid ould me. Any experience with suitable carbs? Many thanks, and apologies. Jim
  3. Bultaco 199A Ingition

    Many thanks, Carl. I have a parts manual and the one marked VAR 41-52 will fit a 199A, however I have now ordered the kit from Powerdynamo in Germany which has the flywheel and rotor all within the kit. I appreciate you getting in touch
  4. Bantam - 4 speed into 3 speed look-a-like?

    Dont quite understand. The 4 speeds use electronic ignition mounted where the stator used to be and you just modify the relevant 3 speed outers to fit. You dont change the crank. B175 is much better crank anyway.
  5. Beta Evo 250cc 2017

    Time Left: 27 days and 23 hours

    • FOR SALE
    • USED

    Excellent condition Just been serviced inc exhaust repacked, fork oil & gear oil. Not been used in the last 12 months. Great bike, ready to trial. Bike is road registered. One or two small marks as expected with used trials bike. Can assist with delivery if required. £3900 Ono 07769159483

    3,900.00 GBP

  6. TY175 Clutch Release Arm removal

    feetup, thank you for your response, fitted the chain fired it up and the clutch seemed to work perfectly as I rode around the garden, so as you advised it was purely drag. It shows what a great resource these forums are, especially to us newbies, thank you!!! Mark
  7. Today
  8. Engine Oil Vent 4Rt Modification

    Hi Jimmy. Do you have a filter on either of the head breather pipe or the transmission breather pipe? I'm currently rebuilding my 2005 4rt and noticed the strage tank is missing and both pipes were just up at the headstock above the radiator.
  9. Montesa breather set up

    Thanks for the clear information. I've been rebuilding the bike completely, I replaced the old airbox drain cap with a sherco one as the old one went rock hard. Im almost finished building the bike I just noticed it was missing this strage tank and the pipes where just left up at the headstock. I'll have to order a strage tank. I'm guessing the transmission breather goes into the strage tank too?
  10. Help needed with 2009 4RT

    No I don't mean "just bash it"! Create a lip/cut/hole near the edge of the cap just big enough to get a good seat for the punch and GENTLY tap it anti clockwise. No need to go silly with it. The timing mark is stamped on the flywheel amongst other things, visible once that cap is out. Do you have the manual with the bike? If not, I'm sure someone can provide a link.
  11. Efi

    The negative pressure is actually createted by the venturie principle, similar to aircraft wings. The piston acts as a pump, but without the venturi, atmospheric pressure in the float bowl alone wouldn't cause the fuel to flow/atomise.
  12. Efi

    Yes my mistake. Injector pulse width. No problem with reading good info. Talking about myself - I’ve been known to write a novel! (Or some would say - drivel). It’s not difficult to imagine then , that Vertigo , in this case - ran into conditions the ECU couldn’t compensate for. Or at least outside it’s set tolerances. My bashing originated from their insistence in using an off the shelf unit - rather than manufacturing or sourcing a bespoke unit to cover all eventualities. They now have 3 years worth of worldwide data and feedback. Interesting to see what they do with it - and where they go next.
  13. 1996 JTR 250

    You tried Jim Snell at Rising Sun Imports? 4474 W 500 N, Earl Park, IN 47942, USA Hours: Open 24 hours Phone: +1 219-474-6656
  14. Advice on buying a Vertigo

    That sounds perfect to me, been wanting to go down there for a while now and this is the perfect opportunity. I’ll put it on the calendar. Thanks!
  15. Efi

    Ok . Isn’t the pilot air screw also open to the atmosphere? I’d assumed that differential between negative manifold pressure and the atmosphere - to be the thing that carburetors rely on to jet? Which is why I asked whether the air screw ( not the pilot jet sry) was not an atmospheric compensator. If it isn’t what is? That’s if you don’t mind covering the basics.
  16. Advice on buying a Vertigo

    I would have a ride down to Cloburn on 30th June, they're having a BBQ and test day. Tom at Cloburn will give you some advice as that's what he rides. Worst case scenario - sausage in a bun. They are a powerful bike, a 250 might be better.
  17. Efi

    That clears that up then ...😵
  18. Freeride change

    Front forks and gearbox for a start, probably rear suspension unit too. Possibly fork yokes.
  19. Efi

    But if it’s the mixture screw, allied to the throttle slide position to achieve the smoothest slowest but even tick over it could be. My Honda CBR 600 FT had to air rams that forced air into and over the surface of the carb float bowls which gave the engine a slight power boost at high speeds. Atmospheric pressure kindly presses down on the surface of the fuel causing it to flow, when the engines bouncing around being used it’s the adjustments that then control the amount of fuel so really a kind of equalisation if you will....I’ll get me coat then shall I? 🤓👨‍🏫 🃏
  20. beta 300t4 clutch fix

    I put one thinner clutch plate in my 2016 300 4T Factory over 2 years ago. It made the clutch pull a little easier, it's still running fine, and i am hard on my 4t, often using third gear in tight spots.
  21. Efi

    I guess by duty cycle you mean injector pulse width. Yes I agree that efi is multi adjustable and to some extent self adjusting/compensating, but only to the limitations of the ecu. There by hangs the tale, the bigger the ecu memory and it’s amount of look up tables the better equipped it is to deal with ambient air temp, altitude, air mass density and flow, along with engine temp, fuel rail temp etc. Ditto for the ignition map (that’s what I used to teach others about....3D mapping and fault finding). My Aprilia Mille was right from the word go with built in restrictions and when they were removed and one wire cut, again it was right. My Aprilia Future 1000 efi was just plush and smooth on or off the throttle. My Aprilia Pegaso (don’t laugh I liked it)was just plush and smooth on or off throttle too. My efi Yamaha 660 SM with such a large piston to use would nod its head and squirm about like a drunk donkey and that has an ecu you can play with the basic settings on but the memory is only concerned with E.U. emissions. I fitted a power commander and dialled out the staggering and shunting that on the road was a real pain. Whereas my 990 KTM Adventure ( fantastic bike) was right from the word go, because like the Aprilia it has a better and bigger memory with a more thought out mapping and each time it went in for service the ecu was always updated to the latest spec, that’s how it should be done. When it comes down to low speed engine response a carb can prove itself to be better, as most fuel injected engines run at 850-950+ rpm any lower than this and they tend to falter and stagger usually shuddering to a halt with no throttle pick up, unlike a carb which will allow better progression and the engine to idle down below 700 and further. Where a carb does suffer is float bowl issues when the bike is laying on its side and the engine usually floods and stops unlike the efi which doesnt know up from down unless there is angle of the dangle sensor keeping tabs on things explosive (rapid burn I should say). There I’ve said my piece, now let’s all play nicely 🙂🤪🤗🤓and remember what I mentioned in my first response....with out the old bikes the new ones wouldn’t have got developed....do you remember Wal Philips he used to produce a strange thing called a fuel injector but it was really just a very long venturi that dumped alarming amounts of fuel into the engine, full throttle or nothing...scooter boys loved em! Mercedes-Benz had mechanical petrol injection in there cars with no ecu just linkages to control fuel rack movement and delivery. The tricky part was balancing the throttle plate movement to match fuelling...tedious but rewarding. When everyone went efi the first problem was keeping the petrol in the system as leaks tended to be frequent. Sorry I’ve gone on a bit, but it’s great to be able to debate a subject and enjoy the banter👨‍🏫🙂👍
  22. Freeride change

    Apart from rear fender ,fuel tank, front pipe do you need anything else to change a freeride into a trials 4rt.
  23. Efi

    If that's a serious question ? Both petrol and air screws control the mixture at low revs/ throttle openings, the float bowl is open to atmosphere courtesy of the vent tubes, so in answer to your question, the pilot jet is not an "atmospheric pressure equalization valve"
  24. Repsol 75w transmission trial oil.

    I think you should use Repsol oil in a " Montesa Repsol " It just makes sense !
  25. Efi

    Aha. Would that be the Pilot air screw then?
  26. Efi

    Really ? Your doing it again The pilot jet is the part which supplies most of the fuel at low throttle openings. It has a small hole in it which restricts fuel flow though it. Both the pilot air screw and pilot jet affects carburetion from idle to around 1/4 throttle.
  27. 2018 Sherco 250 Factory vs 2018 TRS RR 250

    From what i have heard the TRRS is a spot on bike with the power being there when you need it, the geometry is good as well and they look stunning! Not sure about the Shercos but i guess its personal preference in the end!
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