fastducs

Start by cleaning your carb. Pay particular attention to pilot circuit. The pilot jet is 2 parts in tandem. Remove them both and clean thoroughly - the holes in pilot jets are really tiny and easy to clog. While you are in there, take note of what size pilot and main jets you have, and what the needle clip position is. Take note of your current weather conditions, and do a search on this forum for "jetting".

This may be obvious, but have you checked your forks for alignment? Perhaps they are twisted in the triple clamps? Take a straight edge and put it across both fork tubes right above the seals. Take another straight edge and put it across both fork tubes near the top triple clamp. Now sight down the tubes and see if straight edges are parallel to each other. Best to use long straight edges, since longer ones will exaggerate small amount of misalignment, and thus make it easier to notice. Or maybe as simple as bow-legged forks? Perhaps if you changed front tire in a hurry? Loosen the front axle pinch bolts on the right side of the bike, bounce the front end a little to let the right fork settle where it wants, and then tighten pinch bolts again. Any chance you bent a fork tube? Or over-tightened the triple clamp pinch bolts? IMHO, headstock bearings shouldn't have any impact on fork stiction. If you decide to get into the headstock bearings, be careful. Upper triple clamp sits on top of a ring nut which sets tension on the upper bearing. This nut is threaded onto the steering stem. There is a large bolt through the top of the triple clamp which threads into steering stem and tightens upper clamp against the ring nut. This is all very common on many other bikes, but what makes it different on the 315r is that everything is aluminum rather than steel. The rather thin ring nut is aluminum, and so is the steering stem. This means you have just a few turns of soft aluminum threads to counteract 69 N-m of torque from that large top bolt. When I bought my bike, the top bolt was very loose. Upon further inspection I found that the steering stem threads (where ring nut threads on) didn't hold up. I didn't feel like paying for a new stem, so I machined a custom distance collar to sit between upper and lower bearing races, similar to what you find inside your wheel hubs.

I haven't done a bottom end on the 315r, so I can't advise you on that, but I have done a top end a few months ago. It is straight forward, so if you've done a top end on any modern 2-stroke, then it will be no surprises for you. Unbolt skid plate at the front, remove both frame downtubes, and radiator comes right out and gives you plenty of room to access the head and cylinder. The only tricky bit I remember while putting it back together was trying to torque one of the head bolts to proper spec. It was the rear-most bolt, and there just isn't much room to get at it. Getting the skid plate bolted back up was a little tricky too, so I had to get creative with a large C-clamp. But I have an aftermarket skid plate, so I don't know if the stock one is equally challenging. BTW, you can remove magneto cover, grab a hold of the flywheel, and see if you can move it up/down or left/right. That will give you an idea of whether or not main bearings need attention, and only costs you a magneto cover gasket.

91015-425-832 Bearing, Head Pipe Upper You need 2 of them. It is a common Honda part. For example, 1996 honda xr200r uses them: http://www.ronayers.com/browseparts.cfm?Se...he.ronayers.com

How about nylon rope instead of plasticine? Move the piston down into the bore, then cut a few feet of nylon rope and coil it inside the bore on top of the piston. Reinstall head, then kick gently as suggested by feetupfun

The damping adjuster that you are referring to can become corroded inside, and "freeze". The adjuster is steel, and the body is aluminum, so it is fertile ground for galvanic corrosion. If you keep trying to turn it with more force, it will shear inside. Mine did. So I had a local suspension shop (GMD Computrack Boston) rebuild my rear shock, and they had to fabricate the broken adjuster because Showa will not sell it. GMD made a small batch of those adjusters, so I'm sure they have a few left over. Have you rebuilt shocks before, or do you have a local suspension shop? If you weren't on the other side of the Atlantic, I would recommend you to send your shock to GMD, and they will rebuild it for reasonable money, which includes all new seals, oil, nitrogen, etc. On the other hand, the dollar is so weak against the euro right now ... anyway, you do the math. Here is GMD contact info: Peter Kates GMD Computrack Boston http://www.computrackboston.com/ BTW, it might be a good idea to periodically turn all adjusters back and forth to prevent them from becoming "frozen". Good luck, Vitaly

I'm relatively new to trials, so can you explain the zip-tie trick please? Are you saying to replace the 2 side bolts which attach the mudguard to the airbox? Are zip-ties really that much more forgiving than bolts? Or do you have to leave the zip-ties loose? And what about the center bolt which attaches mudguard to the fuel tank and frame?

Just to weigh in as a pure rider/consumer: I ride everything from street to enduro, and recently got into trials, and I own everything from mainstream Japanese bikes to exotic Italian. I bought my Montesa used, and spent a significant chunk of money rebuilding it. I consciously try to support my local dealers. My local kawasaki dealer gets my business because they stock a lot of parts, even though they are 15-20% more expensive than online, and occasionally I have to wait for the parts. But they try hard, and I appreciate it. I can afford to pay a bit of a premium in terms of $$, though I will draw the line at getting ripped off. Give me a fair price (not cheapest - just fair) and you'll have my business. But what's far more important is my time. If I order parts thru my closest Montesa dealer and then wait 1 week for parts to arrive, I then have to drive 1.5 hours each way to pick them up. My wife can forgive me a $300 hobby expenditure on eye candy for the bike, but she and the kids get ticked off if I spend half of Saturday picking up the parts. And please don't suggest to order thru my local dealer parts which he doesn't have, and then have him re-package and ship them to my house - it takes twice as long and costs even more, and what do I do if it's the wrong part and needs to be returned? It quickly becomes a logistical nightmare. Given the tremendous cost of inventory coupled with low demand I can't really fault my local trials dealers for not stocking much. So my challenge to the importers is as follows: please make it easy for me to support my local dealer! Let me order parts thru my local dealer, but drop-ship them directly to my door. I ride very few trials events, so having parts available at the events (which themselves are a couple hours away) is not much help to me. I also promote trials when I get the chance. I sometimes go trail-riding, and enduro guys always come over to gawk at the seat-less bike. A few even take me up on my offer to take it for a spin. So if you want to promote the sport then this would be a good place to start. Have a demo truck at a few enduros and HS events, but mainly I would say you need presence at turkey runs - a lot of racers and recreational riders attend them. A hard core enduro racer would mostly be interested in trials if he thinks it can improve his enduro riding (thanks to Taddy, Geoff, and Knight) and recreational riders are open to trying new things like trials just for the fun of it.

I think Lewisport offers keihin conversions. http://www.lewisportusa.com/

You didn't say which 'tesa you have, but my answer would still be the same: It's not your plug affected by the temperature difference, it is your carb jetting. If this concept is new to you, just google "Spanky's Jetting Guide" to get you started. Regarding your question on octane: I use a 50/50 mix of 93 octane pump gas & 110 octane VP-C12 race fuel in my 2000 Cota 315r. 93 is the highest octane we can get at the pump. Keep in mind this is (RON+MON)/2 octane rating method that's used in USA. Other parts of the world may use a different rating system.

Just out of curiosity, what size jets and needle clip position did you end up with? What temperatures and elevations do you ride in?

Here is a parts diagram: http://www.apexmotosports.com/montesa%20pa...20book/e-10.htm Another source here: http://www.racecar.co.uk/dellorto/ click on Motorcycle Carbs, then click on PHBH/L I've just gone thru my carb, and I took some high resolution photos. So if you need something specific, just ask and I'll see if I have a suitable pic. My bike is a 2000, so I have the PHBH26CS carb. I think your 98 has the same carb.

Anybody got a .pdf for the 315r? My printed manual has gone missing, and it is a royal pain without it.

FYI montesa changed carbs in 2001 from Dellorto PHBH series to PHBL series. But as far as air screw goes, it is tunable for each specific bike to match conditions of the day, such as altitude, temperature, humidity, pressure. I'd start with 1.5 turns out from fully seated, and go from there, assuming that your jetting is pretty close to begin with. Keep in mind that the air screw has the most effect from closed throttle to about 1/8 open. The rest has to be done with jets and needle.

Check out http://www.thedbsnorkel.com/ You could also try a stock silencer from a KDX200 or KDX220. You should be able to find one cheap, since most people swap them out for an aftermarket silencer. Please post your results. The noise issue is becoming a big problem everywhere.

Hi all, The rear shock rebound adjuster on my 2000 cota 315r sheared inside. It goes round-and-round and never reaches a stop. I hear that clickers often seize on older bikes. Unfortunately you can not buy a replacement clicker from Montesa, nor from Showa. I was told that I'd have to buy a whole new shock. So I need to have a replacement clicker machined. If other people have the same problem, then I could ask the machinist to produce a batch of these clickers, which should considerably lower the per-clicker cost. So please let me know ASAP if you would like to get in on this. BTW, I am in north-eastern USA, for purposes of estimating shipping cost.

How is your exhaust header? Lots of carbon buildup in there? I'd get that cleaned up first. Then I'd try a leaner pilot jet, and maybe lowering the needle by 1 clip position. These are inexpensive things to try before you spend lots of money on CDI, etc.

How did you loosen it? Did you use an air impact gun? A suspension tuner I know showed me how he tightens it in cases when he doesn't have a rod holding tool. He uses the impact wrench just enough to get it to the point where it doesn't spin, and then does the final torque by hand. The key is to use very short bursts with the air gun to take advantage of the inertia. Do not simply hold the trigger, as that will indeed spin the internals round-and-round. It also helps to apply a pulling force to the internals while you're doing this. Personally I don't like the air gun method. I usually try to figure out what the rod holding tool is supposed to look like at the end which engages the rod, and then I fabricate my own. Since I'm not a professional to whom time is money, I can take my time making this tool. Usually it is a matter of finding the proper size (usually large) bolt or nut (depending on specific fork type), and welding it onto the end of a metal tube. So Johnny, since I haven't done my forks yet (but soon plan to) perhaps you can do me a great favor, since you've got the fork disassembled. What size/shape is the cartridge end where a holding tool would normally engage? BTW, do you have Paoli or Showa forks?

Johnny, thanks very much for your answers, even if that makes you the proverbial bearer of bad news :-( Oops, too late :-) Thanks, I made my own, and that did the trick. Actually I was asking about the range of motion of the shock shaft. Really? I don't mean to doubt you, but as far as I know, typical shock construction contains both a pressurized nitrogen bladder, and several hundred cc of oil. Are you saying that the mont's shock does all damping by somehow flowing pressurized nitrogen thru constricting orifices?

I have recently acquired a 2000 cota 315r, along with a manual, but it turns out the manual is for a '99. I know that the '99 forks are very different from '00 forks, but I don't know about the shock. Anyway, since I can't rely on my manual, here are my questions: 1) The rebound damping adjuster (purple thingy) turns round and round, and never reaches a stop in either direction. That contradicts the way clickers work on all other bikes that I've owned. Is my clicker broken? 2) On the opposite side of the clicker is a screw-in plug. I unscrewed it, but all I see is a solid dead end. What is the function of this plug? 3) How do you remove the shock spring? Do you have to compress it with some sort of clamp? 4) What is the length of shock shaft travel supposed to be? 5) What type of oil, and how much? Thanks for any help.

I'm sure this topic was discussed before, but search doesn't come up with anything relevant for some reason. So here is my question: I have a 2000 cota 315r. What the heck is in that mid box? I am talking about the portion of exhaust that is between header pipe and silencer, i.e. what would normally be considered an expansion chamber. It weighs a ton! What is between the outer aluminum welded case and the perforated inner tube? Is it packing like in the silencer, and if so, then how do I repack it? Or is it just a huge amount of carbon buildup? Can the perforated innards be removed?

Hello. I recently bought a 2000 cota 315r. The bike currently has a stock reed block installed with some sort of carbon fiber reeds. Looking closely I see that 2 of the 4 petals have a short nylon tensioner, and the other 2 petals have a longer tensioner. By "tensioner" I mean a small flat nylon rectangle which is about the same thickness and width as the reed petal, and is about 5mm-10mm tall. It installs between the petal and the reed stop. The bike also came with a Delta VForce-2 reed valve still in the box. Previous owner never got around to installing it. So my question is: since I've got the bike apart at the moment, should I go ahead and install the Delta Force reed valve? If so, then which tension setting should I use? What can I expect from this reed valve? I should mention that I'm just starting out in trials, so smooth and manageable low end is preferred.

Thanks for your welcome, and for the info!

Hello. I'm yet another trials newbie, and I live near Boston, MA (USA). I've been riding street for many years, and recently started trail riding. Most trails around here are very tight single track woods with lots of rocks and technical sections, so it seemed natural to try my hand at trials. I just purchased a 2000 Montesa cota 315R, and was glad to discover a monty-dedicated sub-forum here. Anyone else here from my neck of the woods?