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Everything posted by marlintec

  1. Hi all, To new sherco models (2010/11) it is worth to flush througly the alluminium gas reservoir, as well as the Dell'Orto vacuum gas pump, lines included. The manufacture of ally produces lot of tiny particles that may interfere with the pump operation. Fit a in-line filter before the pump also is a good tip. In the electrical part, now it's the time to waterproof with silicone all the connections. Best check the screw connection of the spark-plug cap and HT coil and reinforce it with thermoretractile sleeves. You may also fit a better quality spark-plug cap (all-silicone without resistance). Cheers and seize your bike! JM.
  2. Hi all, The Dell'Orto VHST is very sensitive to float level, much more than standard PHBL. The first batch of VHST carbs were prone to fail at the level-valve, then caused the bad reputation when the GGPro (280) appeared in 2003. After that, the factory re-designed the level-valve system and the carb worked well when properly jetted. I have a unit of the first batch (actually designed for the Cota 315, when Dougie were riding it) and found a better stability when I increased the lenght of pilot jet, allowing to aspire gas 4 mm deeper in the vase (details in http://www.terra.es/personal9/marlintec/taller/ ) I wonder if the new configuration of Sherco 2010, with a fuel-pump could affect adversely to the level again? Cheers, JM.
  3. marlintec

    The Oko 24 Rock Test

    Hi, Great information in this thread! I'm not a great fan of four-strokes, but if it could be the way to mellow the beast 3.2 to a more docile creature, maybe I could try one on the future. The way I reduced Keihin PWK 28 to 26 are two sleeves of aluminium pressed into the bore. You only have to check that the front one has the hole for the starter circuit and the pinhole for idle circuit. The back one is just beveled to follow the trumpet. Of course, none must interfer with the slide... But... if you start from a new carb, maybe it's easy to bore out a 24 mm. If you remember the first GasGas (Halley, 1986) they fitted tiny Dell'Orto of 25 mm, bored out to 26. They were 327 cc engines... Cheers, JM.
  4. marlintec

    The Oko 24 Rock Test

    Hi, We also test a OKO/KRP 24 mm in a 250 cc GasGas with similar results: increased feel at low rpm and quite less power at high (the complete report at: http://www.todotrial.com/ttactual/taller/c...-keihin-krp.htm ). In our opinion, the 24 mm carb is just a little small for 250 for those that ride big stuff, but it is great for classic riding. A more equilibrate combination for all users is a Keihin PWK 28 sleeved to 26 mm. BTW, the ''balance tube'' is a third jet that injects gas at the ceiling of the diffusor. Is a small jet (10, in comparison with pilot 45 or main 125) that affect only at WTO and can be eliminated for trials use. In any case, almost any carb in the range (Keihin, OKO/KRP, Dell'Orto VHST, Mikuni VM) is better than the standard Dell'Orto PHBL. Cheers, JM.
  5. marlintec

    2010 Sherco

    Hi, We also have more confidence on carbs, but it's clear that the future is owned by FI even on two-strokes engines. Something similar happened with the electronic ignition. How many of yours want their bikes with the old Lucas ruptor? The 250'enduro shercos (FI) are really creamy bikes. I feel that is the near (maybe not inmediate) future of sherco's 4T engines. Let's time plays. Cheers, JM.
  6. marlintec

    2010 Sherco

    Hi, The distance between filter box and carb could be as narrow as in normal bikes if the cylinder is flipped 180 degrees. This has been done before by Martin Clerch in a '94 Aprilia Climber ( http://www.scottishtrial.com/esp/clerch/climber.pdf ). The same for two-strokes or four-strokes. However, my first concern is the heat propagation between exhaust and fuel, specially in the 4T. Cheers, JM.
  7. Congrats, Borus... Are you aware that it's necessary to bore out the cases to fit the wider neck? Cheers, JM.
  8. Hi, Sherco makes two kind of exhaust: "R" type (usually installed on the bike) and "S" type (S stand for 'silence') that you could choose before buying the bike. The only advantage of R exhaust is at high rpm, so I feel that most of trial riders could do enough well with the S type. I really hate the 4S bark in the woods. Also, in Spain we are having a lot of problems with off road bikes and environmental laws. We shouldn't add more fuel to the fire. Cheers, JM.
  9. Hi Wayne, You're happy with your new bike, this is good! I have a question: Sherco has developed a small vase that fits on the base of carb, just to increase the cuvett volume (it seen before on Beta's mikuni). It also consist in an extension of the needle jet. Has your bike these modifications? On the small pilot jet with small air screw opening: the 317 cc engine has a tremendous aspiration, even at idle. For the same carb diameter, the bigger is the engine, smaller should be the jets (look at the 1.25 jets in comparison with 2.9). Maybe the standard setup is more adequate than a bigger pilot... but if you feel it need, maybe it's time to ask Paxau or Ryan? Good luck with your new bike, I'll wait to hearing news from you, keep us informed! Cheers, JM.
  10. Hi, The best solution is a GasGas disk (rotor). The squeal dissapears and brake gets stronger. You can choose between fixed (GG '06) or floating (GG '07 ->) disks. Sherco use floating disks, but both types are useable. Lots of spanish riders have changed, look an example here The Sherco'09 batch would probably wear new disks. Cheers, JM.
  11. Hi Wayne, did you make the choice? Cheers,
  12. Unfortunately, it is very usual in all sherco models. If you want something fancier than silicone, may try this: Is a very easy shape that any machinist would build for not much money... and you could change to your future shercos. Cheers, JM.
  13. Certainly not. Here you have the exact relationship and an approximate equation very useful for trials. http://www.terra.es/personal9/marlintec/ta...ientopiston.pdf Cheers, JM. P.D. Great job, Cope!
  14. Anyone know if the bike is tuned or straight Out Of The Crate Standard with these wins?..... Yes. I was talking with Paxau before and during the event and he said that Oliveras' and Bruand's bikes were standard. The only difference was in the exhaust. Sherco has developed a less restricted muffler for competition (they name it as "R" version) but also can supply the standard or "S"ilent version. Respect to the previos model, the new flywheel cover holds the tip of crankshaft with an extra needle bearing. This modificiation reduces vibrations and gains extra rpm. Also there are some changes in the machining of head to rise the valve elevation. The 3 units I saw during the event (Oliveras' , Bruand's and Paxau's) were in perfect running all the time. Cheers, JM.
  15. marlintec

    Sherco 3.2

    Hi Ishy, Heared from Paxau's shop: in a month we'll have the bike in sales. Until now, a few number of bikes have been assembled with '07 specs only for testing purposes. Your bike looks great! Regards, JM.
  16. To paint a tube is a lot cheaper than to chrome it. Both companies are trying to reduce costs, evidently. Cota 247 also had the chassis painted in black... Cheers, JM.
  17. It's the first time I see this shock. It seems that GG has changed the model at middle of production. Mine has different cap, and is adjustable in compression. This silver shock may not be adjustable in compression. Could be a cheaper version? Evidently I will not put the hand into the fire for any manufacturer... Cheers, JM.
  18. Ok, up to you. I'm not working for any manufacturer. Just telling what I've experienced, I thought that the topic was this. I'm not telling what others tell me. Cheers, JM.
  19. Hi Atom, I wouldn't deviate the topic but:
  20. After 4 shercos I've just changed to GG (with a 4RT in the middle). These are my points: - Lightness & manouvrability: GG wins - Suspension: GG wins so far - Engine response: Sherco better at low, GG better at high - Clutch: Sherco wins - Reliability & maintenance: both are the same dog. A little dissapointed with the fourstroke venture, this year I decided go back to 2S. Naturally inclined to Sherco, after applying the above points, I dismissed the sherco '06 for its low capacity fuel tank, its Leonelli ignition, the ugly (to my likes) rear mudguard and the hitting between tripleclamps and the new chassis. Sherco bikes were the most logical bikes until '03-'04. From that year I feel that its quality has dropped some notchs, and GG has gained the lost realiability in '02 and also joined better components than Sherco (
  21. marlintec

    Chain Length

    102 links, if you want the same basewheel. The rule is easy: original number plus or minus the change on teeth. Your standard chain lenght is 101 link with 10/42 gearing. If you add 1 tooth (43) you'll need 102 links. The standard lenght of GG-Pro (250-280-300) is 102 links, so it's easy to find. Cheers, JM. By the way, I've now a GG Pro 250 with 10/41 gearing (11/42 standard) and I like much more (3rd. more useable).
  22. marlintec

    3.2 4 Stroke?

    I heard from a reliable source that Shercos 4T won't be in production this year. At least before summer.
  23. I had the same problem running with modern full synthetic (Elf XT2, Castrol R2, Motorex CrossPower) from 1 to 1.25 % (100:1 to 80:1). Also I rarely use more than 2/3 throttle. Even in few hour the carbon builds up in head, rings and exhaust. I'm very sure my bike is right jetted. The problem was resolved using semi-synthetic oil at 1.25 %. No ring sticking, no muffler-clogging. Not always the hi-tech synthetic is better. Cheers, JM.
  24. Take a look to http://www.terra.es/personal9/marlintec/taller/ the last item of the list. Cheers, JM. P.D. You may need google translation (Spanish).
  25. Great feedback, thanks. I would like to say that I'm not disappointed with the 4RT, I really enjoy the feeling of its fourstroke engine. It is just a case of results and physical effort what moved me again to twostroke. Ishy and AtomAnt, did you suffered problems of overheating? I'm getting some feedback of the same question in Spain, and the overheating seems to be an important issue. The start problem was also a concern in the Spanish sherco-users. Ishy, why you removed the decompressor set? Aren't you stressing the kick shaft-gears doing so? I have not enough data yet, but seems that the 4RT users are more loyal to their bikes to keep them for one year more (not me). Sherco 4T users seem more prone to change this year? Cheers, JM.
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