dombush

Zak Ham2 is referring to the need to stop the water pump impeller shaft rotating whilst undoing the impeller. You can avoid making a special tool:- Clean the shaft end then wrap it in tape / cloth to avoid the vice marking it. The impeller isnt immensly tight on the shaft (6ft/lb) You will see what we mean in this PDF http://www.lewisport...replacement.pdf Dom

Zak yes, both need draining. There is a cheat with the gearbox oil if your really in trouble (or skint), it involves laying the bike over on its side to stop the oil flooding out when the clutch cover is removed. Careful, the tank is best removed (leakage) and you must cover the open clutch area to stop dirt getting in.

Hi Zak that "little hole" is the water pump tell-tale that indicates that the water pump seals are starting to leak. The good news is that a little leak can go on for a while before it becomes a gusher. However you cant tell when this might be, and its quite an easy job anyway. The job itself involves removing the clutch cover, dissasembling the pump impeller shaft assembly, Inspect the shaft for grooves / wear, replace the seals, reassemble. It took me an hour and didnt involve any really special tools. Dom

Mike This sounds very much like pre-ignition, where the "clang" is caused by the fuel / air mixture being ignited by something other than the spark plug. This happens too early (similar to massively over advanced ignition) This "something other" can be a few things: something over-hot in the combustion chamber (carbon build-up, wrong grade spark plug, too high compression for fuel, too large a squish clearance etc.) ignition too advanced, causing over heating of the combustion chamber leading to similar issues to above Incorrect exhaust / silencer causing back-pressure, leading to similar issues to above. This is very rare, so unlikely. Running too weak = running too hot. The over-run pre-ignition is not that dangerous, this is becuase the engine isnt under load and because its infrequent. Pre-ignition under load is much worse and can lead to melted / holed pistons. Be aware that squish is confused with compression, they are inter-related but completely different facets. Some of the suggestions made already are potential solutions. Do the easy things first, suggestions are: Using super unleaded could solve the compression issue. Check the ignition is set correctly, check the plug type. Clean the carb thoroughly, check jetting vs std spec. Check the squish clearance by crushing some soft solder inserted through the spark plug hole. Remove the cyl head and barrel. De-coke the cyl head and piston crown. De-coke the exhaust port and exhaust header pipe. Dom

Often when the seal leaks air it doesnt pour oil out. Normaly there will be some under the flywheel when removed, all engines instances are slightly different. It can also depend on what sort of main bearing seals (shields) are fitted. As far as the breathers are concerned. You only need to dip them for long enough to see bubbles / suck up some water. It will be very obvious very quickly. Not sure if the 315r has 2 breather hoses, someone else can pehaps comment. If it has, then blocking one while testing the other and vice versa. The air leak you are looking for sounds quite big, so youre looking for something reasonably obvious. Remember that the crank seals are about £10 for the pair, its just the fitting that requires a bit of experience.

Rockgardener you are looking in all of the right areas, and i like the suggestions so far. I would doubt its a carb fault because of the behaviour with the choke on, this suggests a big air leak rather than a jetting failure. The most likely places for an air leak (non crank seals) are around the intake rubber / reed valve joint, Given you have checked these and all looks good, i would move onto replacing the mains as a next step. Not sure if the mains can be replaced with the engine in situ on a 315r, but this is possible on most modern engines. Start with the ignition / flywheel side first as its the easiest and is only a 30 minute job (at least on a Gas Gas or Sherco). Moving onto the other side, usualy a sign of a leaking clutch side seal is air being sucked / blown out of the gearbox breather. Clearly if air is being drawn into the crankcase via the gearbox, this air has to enter the gearbox via a route. This route is usually the breather, so a simple dip of the breather pipe into a glass of water is a good identification technique. Dom

Hi your right, it is daunting at first but like anything its worth perservering to get the best from it. Clubs around the SE tend to use the coloured markers, all based on the Red/Blue principle. Once you get it, its reasonably logical. Only once have i been so bamboozled that i have failed to get it, turned out that the route crossed over itself!!! Dom

Hi sounds like something might be dropped into the intake port or exhaust port. If it were me, i would check what i could see with a torch to see if anything has dropped around the side of the crank etc. If nothing is found, i would drain the coolant, remove the head and the barrel. As well as finding any potential problem you can give it a bit of a de-coke, check the ring-gap etc. Other things worth checking are:- Take the flywheel cover off to check something hasnt jammed around the flywheel. Take the clutch cover off and check something isnt fouling the clutch basket or jamming between the clutch basket ring gear and the crank pinion. After that things get a bit more serious !! Dom

Jonny looks good. Likely that the previous owner really cared for it. So now you need to dial it in as you would your mx bike. So, while on full lock trying to balance, think about the controls positions, particularly the handlebars as shifting your weight from wheel to wheel to get grip is critical. More realistic exercises that i found a benefit in the very early days were. Figure 8 full lock turning at tickover; timing the clutch and back brake; looking up at where you want to go. Progress can be judged from the speed / duration you can get to full lock and hold and how little you need to look down at the front wheel. U turning on a heavy camber / steep bank (up, turn, down again). Progress = less speed (even stop during the turn) Riding slowly along a medium camber and turn up it. Dropping into a steep V-shaped ditch and timing the application of throttle to get out (i found this very difficult at first). Progress = no wheelies and lack of exit speed. Getting up a long steep hill, bleeding off power as you go to then turn and ride along the ridge at the top. Progress = turning along the ridge without needing any flat. Descending a steep hill at walking pace and turn back up. Again progress = lack of flat area needed and ability to turn back up sooner. Getting over logs using the double blip technique. Progress judged by the degree of control / composure and LACK of speed used (can you stop with the rear wheel on the log). Good to hear your trying hopping the front, exactly what i did. Have to say that i have not yet needed it as most easy / novice routes focus on basic bike control. Look forward to seeing it a local trial sometime soon. Then the other new skill comes into play... reading the section route flags, planning your tactics. Dom

The reason i would send it to Langcourts with the piston is they will have much much better bore gauges than your average mechanic. Also this way you can deliberately chose an A or B piston and know that you can go up a size or two in the future. It would be annoying get the barrel back and have to fit a C or D to a new bore. Where pistons are scarce like classic bikes etc its often cheaper (or there is no alternative) to match the bore to a used piston rather than the other way round. However, i wouldnt be anal about it. Like me, Chris at Splatshop has probably got a reasonably good bore gauge that's good enough. Given that many barrels are tapered and / or oval from new (yep!!) you will potentialy also get a better component at the end of this. Dom

Because we use lots of small fasteners (M2.5, M3 etc) into a variety of materials it's critical that we dont under or overdo it. When we get a new member of staff we test them for their "feel" of the correct torque. We then check the actual torque with a calibrated wrench. As a bit of fun the whole team always joins in and the experienced guys are remarkably accurate (usually within 10% on the regular sizes). Its always great to see that the apprentices get to +/- 15% quite quickly (a couple of months). At this point we dont mandate a torque wrench except for safety critical stuff (like ham2's boilers) Dom

Hi a seizure doesnt always = new barrel. Firstly, Its important to remove any aluminium deposits to reveal the actual plating damage. Scratches Clearly if the scratch is deep (can feel a step with your finger nail?) then the games up and it needs to go for replating. While you can hone Nikasil barrel, this is only relevant for very minor blemishes (Nikasil does streak this is not always terminal). Very bad scores and more serious damage can be welded and replated. General wear Look closely at the top of the bore (where the top ring reaches TDC). Is there a significant step between the worn and unworn areas? Are there any areas where the plating has worn through (normaly above the exhaust port and near TDC) Get the bore measured with a bore gauge and compare ovality / taper against the manufacturers spec. Piston sizes For most bikes there are 4 sizes of piston for the plated barrel (A,B,C etc) Often you can fit a larger piston into a slightly worn barrel (check the piston to bore clearance spec for your bike) Barrel repair A barrel has to be really bad to make it unrepairable. I've had cracks and gouges welded and repaired. Try Lancourt cyl replating (UK) Costs around £130 for a straightforward replate. Its best to send your piston and desired clearance for best results. Dom

Jonny Took me a while to find these reviews..... 2007/8 model year but you get the idea. gas gas range.... http://www.tmxnews.co.uk/bikes/Gas-Gas-TXT-Pro-125-250-280-300-2007-range-i108 Sherco range.... http://www.tmxnews.co.uk/bikes/Sno-stopping-Sherco-i141 Beta range..... http://www.tmxnews.co.uk/bikes/2008-Beta-trials-bikes-i159 Dom

Jonny the common response is buy on condition first, then age.... however, clearly this is true only up to a point. A 2001 bike is quite old and even if perfect is quite old technology. If my memory serves me correctly a 2001 Gas gas may be a TXT rather than a TXT pro. The TXT has an older design engine and is heavier. The pro range started around 2001/2002 (check on this) and early model years did have some problems. When i bought my 2006 I spoke to gas gas themselves and they advised me to aim for a 2004 onwards. Consider the availability of spares for a 12 year old bike. The Beta was a very popular bike and i personally think Beta's are good quality. Comparing Beta vs. Gas Gas (& Sherco) year against year is a question of taste. Be aware that there are certain years that models took significant steps forward in design. Despite the excitement dont rush, its difficult to wait but keep talking to people. I could summarise what i think of the brands, but all will serve a beginner very well for a couple of years. By then you will know what you want / like. So, all in all my advice is to buy the newest model of Beta / Gas Gas / Sherco that's in decent condition, then spend the time getting it just right in terms of set-up. After that practice, practice, practice.

If you can borrow an impact gun from someone that will be the easiest way to loosen it. Mine came undone using the gun while simply holding the basket still by hand. Alternatively you can make a holding tool yourself using some sheet aluminium and a jigsaw. I wouldnt try pulling the wool over anyone's eyes as Splatshop help out on this forum regularly and they are no fools.

I hardly think anyone would seriously take legal advice from some 2 or 3 line posts on an (albeit excellent) forum. This is called banter / discussion, the food of life. Its OK to have a different opinion. I can think of a number of reasons why someone who might be "realising what he has got" might remove online photos.

Hi an educated guess is thus:- Firstly when the clutch is released, this transmits drive from the crank, via the clutch outer basket onto the inner hub and onto to the gearbox input shaft. Even if the bike is in neutral this input shaft is turning quite fast. Secondly Whining is more often than not bearing related. There are 2 such bearings either side of that shaft. Thirdly If not bearings, neutral allows a number of the gears to idle (rotate freely) on the shaft. There could be a problem here (but i doubt it) It would be interesting to see if the noise continues in the following circumstances:- Engine running, in gear with the clutch in. Engine running, in Neutral with the clutch in / out (youve already done this) Bike on a stand, engine running, (very carefully) take it through the gears and see if the noise is in all gears. Dom

beepee I guess you've got 2 options, OEM Montesa spares from Pidcock or Sandifords. or go for something aftermarket like the all-balls (yes really) kit. http://www.allballsracing.com/27-1166.html heres one http://www.ebay.co.uk/itm/ALL-BALLS-Linkage-Bearing-Kit-315R-Montesa-1999-2005-/181019406191?pt=UK_Motorcycle_Parts&hash=item2a2598ef6f Dom

Hi dn1x None of this is intended to be rude or inflammatory...You made me chuckle with your post as it might have been something i would have said. Hard to grasp before doing it, but it will smack you in the face within the first 10 minutes of your first trial:- The only help that previous MX experience will be is knowing where all the controls are and general bike awareness. Above a certain point bike power is fairly irrelevant. Smoothness / subtlety, controlability, overall balance, supple / progressive suspension are the key. Where tuning parts/ latest spec bikes/ flash clothing is replaced by subtle std bikes possibly 10 +years old, setup and adjusted perfectly by blokes wearing gear that served them for 15 years. The competetive atmosphere of the track is replaced by focused individuals wandering around the section quietly planning their route. You will wonder how that old guy got through the section inch perfect every time where you managed 10 meters before landing on your bum.... Hope i'm wrong, but trials is a completely different challange that needs experience / dexterity / timing that you will grow to respect. Also very sociable and great fun in a frustrating way. I think a well loved. well setup 125 will serve you fine. Strangely the agressive tendency of MX experience might be less ruinous on a 125. Alternatively a 250 will be more suitable if your already subtle and calm (i wasnt). Dom

Ben Removal of the clutch is thus:- http://www.youtube.com/watch?v=hjoj7n74G0s Seriously Ben, keep going and find that debris even if it means straining the oil you removed. Dom

Ben Find that debris!!! dont stop until you do! Although trials bikes generaly dont go very fast, a gearbox seizure is the very worst type of breakdown as pulling in the clutch doesnt help! Removing the chain is the only way to move the bike. In road racing, riders would break into a sweat just thinking about it!! On less concerning subjects....Not getting the clutch cover back on... which side (left or right) appears to be resisting getting back on? Dom

Charlie depending upon the cost of a new (or used) airbox i would consider repairing the airbox. Albeit i have access to a lathe, i would turn up a new insert that fits into the hole from the inside. This part would take 1/2 an hour to make (1 hour max) and a flange on the back would stop the insert from being able to be pulled through. On the other hand if you dont know anyone with the skills / tools then a replacement airbox is the best route. Dom

Jonny Yes Montesa (Honda) went 4-stroke after the 315R. Bear in mind that when it comes to bike choice everything is opinion (including mine), and there is a lot of brand loyalty around. I've got a Gas Gas 250 pro (06) and my son has a Sherco 125 (07). Being an engineer i tend to be steered by function / quality rather than looks which as my wife reminds me... "your so boring!" I like the Beta for its very smooth tractable engine and general build quality. The Sherco is certainly a pretty bike, steers better than my gas gas but doesnt do it for me on the long term quality stakes (I hear this is better now). Never been a 4-stroke man, so wont even comment on the 4RT, Sherco, Beta 300 etc. etc. Suffice to say though in quality terms a Honda will always be a Honda. Cambridge Matchless have a trial on this weekend (snow allowing) which i will be at. Check the website for details. Lots of people will talk to you and perhaps let you have a quick trundle. Dom

Jonny I am a little way away in Cambridgeshire and ride at an excellent club... Cambridge Matchless (see their website) http://www.cambridgematchless.co.uk/ Depending on where you are in Bedfordshire you have a number of options. Look at the ACU website under South Midland Centre (start here) http://www.acu.org.uk/Centres-Clubs/ You will find a list of Clubs, why dont you pick 2 or 3 and go along for a look and a chat? As a Novice starting from enduro 2 years ago, i found the best way to start is just to get out there. My club does 3 routes and starting with 2 or 3 "Easy route" trials got me confident and prepared to step up to Novice. I met a number of people who offered me good advice and help. Its true that its best to buy the bike that suits you but in all honesty when i first started i bought a good Novice bike from the bigger 3 (Gas Gas, Beta, Sherco) and learned to ride on it. Two years on i realise that i would have preferred a Beta, but the gas gas 250 i have is still better than i am and got me a long way. Your budget should get you a 2007-2009 bike of decent condition. I advise buying on condition then year in that order, parts are expensive (nothing compared to maintaining a MX or enduro bike mind) and poorly maintained bikes just burn money if you want something "right". Montesa's are lovely (quality) bikes but the 315 is slightly old now (stopped building them in 04?), however a decent one is well within budget and will take you way beyond Novice level. Dom

Zak Ok, good further information (i need to buy some thumbscrews for you) . It could still be either problem (carb or crank seals), however the likelihood that its a carb problem is greatly increased by this information. A common problem when the bike takes a drowning is that silt / dirt gets drawn into the carb with the water. This likely enters the carb via the airbox into the holes in the bellmouth of the carb that feed the idle fueling circuit (funny that) and often the choke circuit. Another potential issue in these circumstances is that the tiny idle drilling in the carb throat could get blocked. Look down the carb where the slide operates and on the bottom surface of the main airway you will see a tiny drilling or two just beyond the brass "chimney" (The circular brass fitting that the slide needle dissapears into). The solution is still the same as discussed before. Remove all the components from the carb and flush both the removed components and the bare carb body with with carb cleaner. If you havent got access to a compressor buy a can of compressed air http://compare.ebay.co.uk/like/190710459722?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&adtype=pla&crdt=0 and use that to blast any of the jets, drillings, air bleeds. You should be able to feel air coming out of the tiny hole in the main airway discussed earlier. Check every jet by holding to the light and looking for a clear hole, copemech suggested using a strand of wire (strip back a piece of electrical flex and remove one of the strands, or cut a strand of steel wire from a wire brush). Very carefully poke this up centre the pilot jet and dont overdo it as the orifice diameter is very important. so if you havent had enough already give this a go. My hunch is that this is the highest probabilty. After this your probably into getting some help that can be with you beside the bike. Dom