rockgardener

Thanks for the clarifications; I understand much better now and will take extra measures to baby my Pro's transmission!

Okay, so you're saying I shouldn't shift my GasGas like I do my KTM's, but I still don't know what I'm supposed to do instead. Do you mean that I should do as little shifting as possible while trail riding, or that I shouldn't do trail riding at all on this bike? I'm new to trials, but I just attended a two-day trials riding school and learned from multiple instructors that I can be much harder on my GasGas clutch than I would have ever imagined - I'd never start a huge hill climb from a standing start in third gear on one of my woods bikes, and then slip the clutch the whole way up, for example. But that's how we were taught to do it on a trials bike at this school (and it worked great). Same thing applied in lots of other situations, too, and I developed a very different relationship with my clutch than I'd ever had on any dirt bike or street bike before. I now do much, much more clutch-slipping on my trials bikes (I have an old Montesa 315R, too) than on any other motorcycles. I understand (a little) that in competition, a trials rider most often selects a single gear for the section at hand, and just stays in that gear the whole time, relying heavily on the clutch instead of shifting up and down. But nobody at the school said anything about trials transmissions being fragile and unable to take the stress of "normal" shifting (and we even went on a trail ride with one of the instructors at the end of one day). Is this a GasGas issue, or does it apply to all trials bikes?

Thanks for the feedback, lineaway. I'm relieved to know that these sounds may be normal, but I'm concerned about this need you mention to be "careful" during high-speed trail riding. I'll certainly exercise care, but exactly what should I be careful about? I don't do clutchless upshifts or stomp on the gear change lever or anything else that can be hard on a transmission (that I know of). But maybe I'm unaware of something that can be harmful in this case, so please educate me.

Just spent an afternoon doing some relatively high-speed single-track trail riding and noticed two odd noises: 1) shifting from third to fourth produces a dramatic CLUNK, and 2) fourth gear whines loudly, unlike any other gear. I've only had this bike a short while, but never noticed these noises before. Then again, I rarely went past third gear, so it could have made these sounds and I just didn't notice. Are these normal for a 2012 Pro with less than 15 hours? I recently replaced the oil, which was ATF, with more of the same (about 400cc or so - level is 3/4 up sight glass). I don't notice any difference in clutch action. Thanks for your input.

True, the Honda steel plates will work fine -- they're dimpled just like the Apicos. But they're MUCH more expensive - about THREE TIMES the price of the Apicos. And, since nobody is complaining about the Apicos, I can't imagine any justification for spending the extra money on the Honda plates, unless you simply can't figure out a way to purchase the Apicos. Again, I got mine at BVM, no problem; just Google BVM trials parts.

After trying three different types and levels of tranny oil, back-bleeding and readjusting the clutch several times, leaving out a couple of pressure plate springs, and several other superstitious "fixes," I finally popped in a set of Apico dimpled steel plates today (with everything else returned to stock, and Dextron III in the gearbox). The difference is amazing! Zero drag at startup, nice strong engagement, but the most impressive change is the smooth, linear transition from disengaged to engaged - nothing at all like the abrupt, jerky action of the stock plates. I'm not sure any of the other mods really made a significant difference, but this one is unquestionably a major step up. It now feels almost as silky as my new GasGas Pro's clutch, and before it had been nowhere close. I highly recommend these; got mine from BVM - quite reasonably priced at about $26 USD, and certainly worth much, much more for the difference they make. What can I expect over time - does this brilliance fade?

Steel fork is a Paioli, not Sachs.

Trials newb here. Just got a very slightly used 2012 250 Eco at a great price. Trying to get clear on differences from the 2012 standard Pro model. See if I've got it right. Engine internals are the same, but frame is from 2010 Pro model. Fork is steel Sachs unit, instead of aluminum Marzocchi. Header is steel, instead of titanium, and muffler is all-aluminum instead of aluminum/composite. Rear wheel is rim-band-type instead of having spoke flange. Rear brake has separate master cylinder and remote reservoir, instead of integrated unit. Tires are Pirelli instead of Michelin. Airbox is small, instead of new larger design. Plastic is 2010-spec, with different stickers. Is that a complete and accurate accounting? Why is there no official description of the 2012 Eco on any of the Gas Gas websites? Many thanks for your knowledgeable replies.

Finally got out on a practice course for the first time on my new-to-me 2001 315R and really loved it! Problem is, my 17-year-old loved it at least as much as I did - I almost had to wrestle it away from him each time I wanted a turn. So, now I'm looking for a second trials bike so we can ride together and not have to take turns. The only bike currently available nearby is a 2001 Sherco 2.5 (looks to be in good shape). Can anyone tell me how that machine would compare to my 315R? Thanks for your insights.

Thanks for the replies. I've fitted my petcock with a little chain (loose end anchored with a zip tie to the clutch line) so that it's now very easy to pull down and push back up. Good to know this is something to watch closely, and that my bike isn't the only one.

So I need to be more careful to turn off the fuel petcock when working on the bike. And I could have removed and cleaned the spark plug. But I don't know of a bolt to empty the crank case. Do you mean that fuel could have actually poured through the carb and reeds and collected in the crankcase? Where would this drain bolt be? I only know of the gearbox oil drain bolt. Thanks.

About 50 more kicks with the throttle wide open finally brought the engine to life, so there's no question about what happened - the bike was severely flooded. I wouldn't have thought such a small pitch forward would have created such a dramatic problem. Is this normal for these bikes?? Is there a better way to get them started after such a flooding?

My new-to-me 2001 315R has been starting FIRST kick every time since I got the carb sorted a few days ago. I've still only been able to putt around the yard with it so far, but it's been running fine. I put it up on a work stand for the first time to lube the chain. The bike was at a bit of a nose-down angle, with the rear wheel off the ground. After lubing the chain, I realized a big puddle of fuel was forming under the bike. There was no sign of any fuel leak before this, so I can only assume that the fuel was coming from the carb vent tube. (It was dark, the light was poor, and I had to rush out soon, so I couldn't thoroughly examine it.) Once the bike was back on the ground fully, the leak ceased. I tried to start it, just to make sure everything was okay, and it wouldn't even begin to start. I kicked it many times with the choke off and zero throttle (it had been running a short while earlier and was still slightly warm). Then I tried kicking it many times with the throttle wide open to clear it out, in case it was flooded. Nothing. Then I tried kicking it many times with the throttle shut and the choke on. Under no condition did it give the slightest hint of firing. I let it sit for several hours and tried again - still not so much as a cough. Just sounds totally dead. What happened? What's to be done about it? My two-stroke woods bikes will leak fuel through their carb vents when tilted far enough to the side, but it doesn't effect starting unless they've fallen all the way to the ground. Even then, a few kicks with the throttle pinned will get them running again. Are trials bikes so different? Many thanks for any help.

Bike now idles quite nicely after installing the new fuel screw o-ring. I can't be 100% certain this was the solution, since I gave the carb another thorough cleaning whilst waiting for the carb gasket kit to arrive. So I might have dislodged some gunk this go-round that survived the previous cleaning. Anyway, the change is dramatic, and I'm greatly relieved to not have to chase down and repair a main seal leak. Thanks to everyone for all the help!

Even without the use of butane (see previous post), today brought an interesting development. As I was re-cleaning and reassembling the carb per the recently quoted instructions from a Montesa dealership mechanic, I noticed a discrepancy between the parts before me and the exploded view in the diagram. An o-ring and washer were missing at the inboard end of the fuel screw! When I'd disassembled the carb the first time, I assumed it was a complete unit, and simply took care to reassemble it as it had been. I didn't go through, part by part, and take a thorough inventory in comparison to the diagram. I couldn't find a properly sized o-ring in the assortment I had handy, nor a washer that would fit, so I went ahead and ordered a rebuild kit with all the exactly correct o-rings, washers and gaskets in it. Maybe all my troubles have been the result of this missing o-ring, as I'm assuming a leak at the fuel screw would result in the type of lean condition symptoms I've been having. And it could explain why turning the fuel screw throughout its range seemed to make virtually no difference in the motor's behavior. Hopefully, the kit will be here by the weekend, and we'll know if it does the trick. I'm going to wait on the butane test for now...