Don't want these Ads? Why not sign up as a Trials Central Supporter.


  • Content count

  • Joined

  • Last visited

  • Days Won


About sherpa325

  • Rank
    Advanced Member
  • Birthday

Contact Methods

  • Website URL
  • ICQ

Previous Fields

  • Bike
    4xbultaco, gasgas300
  • Club
    Denman & Pacific Park

Profile Information

  • Location
  • Gender

Recent Profile Visitors

5,729 profile views
  1. I think the 280 conversions use a gasgas piston. Most people I know are using electronic ignitions,newer carburetors [Keihin, OKO, Dellorto, Mikuni] and some are reducing flywheel weights, which can be done by using a 250 magneto on the 325's and likewise smaller flywheels on the primary side. The problem with the lighter flywheels is that obviously the motor revs better, but it puts extra pressure on the already average brakes as you lose engine braking. Would love to see some photos of the 370 as I would assume it would be a copy of Martin Lampkins bike if not one of his. I think the factory riders tried a 348 long stroke engine[64mm] in 1976 or 1977, not sure of exact year, but they all went back to the 325 except Martin Lampkin who apparently ended up with the larger bore and larger stroke 370. I am not 100% sure on the factory riders engine sizes so if anyone can add more that would be great. Cheers Greg
  2. From memory they used to rub on the top of the swinging arm and also on the top of the bottom frame rail that the bashplate is welded to. From the 199a on a rubber protector was fitted top and bottom to stop the problem. Inmotion sells these, but they will not bolt directly on your model without a bracket being made for the top run, whilst the bottom one bolts directly onto the alloy bashplate which was standard on that model but not on the 159. So yes they can be fitted but it will require some welding and fabrication on your part. Cheers Greg
  3. All the current new bikes use 28 keihins which is what is on my 199A and it works fine. They are a very clean crisp running carb that works well even if the jetting is slightly off. The 199A came with a 28 Bing so I would stick with 28
  4. The OKO is a copy of a Keihin, I bought a cheap OKO off ebay and it was rubbish. Apparently the genuine OKO is good , so I assume you should buy one off a dealer rather than ebay. Keihins are 28mm and you can buy OKOs that are 30mm but they are bored oval to obtain the larger size, the width is 28 but the height is increased to 30mm
  5. Good to hear, I prefer the keihin though over the mikuni however
  6. They are great to deal with, even living here in Australia. Parts generally arrive in about a week which I reckon is pretty reasonable considering the distance. There prices, knowledge and service are fantastic.
  7. I was just wondering, did you put a centre case gasket in before you tightened the cases up? I remember when I put my 199B back together, with the motor on the bench I was not convinced I had all the gears, but once it was installed in the bike with all the accessories, clutch, chain & sprocket etc was I able to find all the gears easily and it shifts perfectly, but as I said on the bench it didn't feel as positive as the 5 speeds. Cheers Greg
  8. I would be interested to know how many turns your air screw is out, every time I hear your bike it sounds like it needs to be wound in 1/2 to 3/4 of a turn
  9. Borrow your Dad's glasses
  10. Netleys bike sounds like it needs a larger pilot to me,however its very difficult to sort out just watching a video
  11. I see you have bought an OKO/keihin for your Montesa, I would stick that on the Bully and see if you have the same symptoms
  12. It does take a lot of time and patience to get them running crisp, this video is maybe three years old and I think it would have had a Keihin on it. I have run with a dellorto but I would have to say the keihin/oko is the easiest to get running crisply.
  13. I think a 130 would be ok for normal trials use where the bike only hits full throttle for short bursts, but by the sounds of it the bike was being ridden more like a road/trail bike where it would be on the main jet for quite some time so I would definitely go bigger if you intend doing this style of riding - 140 /150. If you go too big the engine wont rev cleanly and will splutter on full throttle.
  14. Elf is used as standard in the Honda Montesa 4rt and the importer/ dealer will usually carry it or know where to get it from. It is the lightest gearbox oil I have found and I would assume this is why it works so well. The GRO extreme oil is the closest I have found to the ELF, but I still prefer the ELF.