oz thumper

Andat are these Showa forks? I am still having problems with Teflon stripping off the upper fork guide bushes. Factory say there is no problem with Showa forks

They are neat but do not have any valving in them so leak limited fuel when you drop the bike. After loosing a couple when you get forward on the tank, the last one I tapped with a coarse starter tap so that it can be screwed down onto the fuel cap plastic pipe, it has stayed in place ever since.

If same as Showa fork on 4RT, the fork spring is in the left leg and has some pre load on it which keeps it fully extended. The right leg has no spring but an airspace above the oil, if this air is at negative pressure )after extending the leg then it will be "sucked ' back down. If when rebuilding the leg you fully extend the leg before fitting the fork cap then you will have positive pressure in their and the it will act like a light spring and will tend to extend the leg when no weight on it. If you undo the fork cap and extend the fork leg before replacing the cap you will be able to see how this works. I was taught to extend the leg prior to fitting the cap to ensure the air acts as cushion at the end of the compression stroke of the fork.

I have run the slow / medium ATC throttle tube for a few years now on 4RT,s, worked well on my 06 bike but on the 2014 260cc bike I would prefer the slow/ fast tube. Problem has been that when I rang recently the said that they were no longer making them. I reckon they are a great concept and really well made and prevent crap getting into the throttle tube when dropping the bike. If they have them available again please post.

Hi Woody and Chrisa, I have a 2014 Repsol (arrived here at end of year) and have had same experience of seal leak and when stripped issue was Teflon coating pealing off the top bushes, which can get under seal lip as well as in valving. No defects on the surface of the staunchions, and bottom bushes and coating were perfect, so appears to be an issue with the coating adhesion being defective. However point is, after dismantling the forks and meticulous cleaning of all components and replacement of all seals and bushes, after two practice sessions leaking from right fork leg seal. When leg stripped have found the same issue with the new top bushes. The problem does not seem to be seals, (as Chrisa mentions) but the coating on the bushes. My issue is whether or not this is recognised as a problem and where to get satisfactory bushes from? My 2006 Repsol forks have only been rebuilt once and the bushes only showed normal wear not bubbling and stripping of the coating. Anybody have further info?

According to the manual Montesa 4RT caster angle 24deg 34', and trail length is 63mm with a wheelbase of 1,320mm. if I recall correctly the TLR 250 has similar angle of 24 degrees.

Hi Chappo, Cant help much with the spring as I am 65kilo and had to go the other way, however both mates around your weight have had no issues with the standard spring rate, I guess it depends a great deal upon the grade that you are riding. Big splats in the expert grades may benfit from a stiffer spring rate where as at the clubman end the softer rate is usually preferred for most conditions. And yes stickers on my '14 Repsol have tended to lift paricularly when the guards get flexed, the stickers are much thicker than the earlier years and whilst very hard wearing don't flex as well, just lift the offending corner and re fix with contact adhesive before it gets too bad otherwise crap gets stuck to the underside of the sticker and becomes harder to fix neatly.

HI Chris, I have had 4RT,s since 2005 without any issue in hot weather of which we also get plenty in W.A. John is right the tank should not pressurise, make sure the std one way valve in the breather tube is the correct way round and clear. Yes the fuel does get hot, I noticed this early on and always try to refuel regularly to keep the pump covered with fuel and increase the volume of fuel taking up the heat. I don't know if this has a major effect all I can tell you is two others over here that tended to refuel only when empty developed pump problems, I have never had any pump problem in the last ten years. I also run 91 octane fuel as recommended by Tarp, not the premium grades. Hope this helps

Only time I had this problem was when the throttle cable was pulled up in the rubber sleeve of the twist grip, this kept the throttle open beyond the starting limit for the TPS. This kills both the injection and the spark. In my case the cable was pulled up when dropping the bike and would not start, had no spark but also a dry plug. Retired and took home and like you worked my way through testing by the book and all was in spec. When I found the cable problem, reseated and fired up first kick. Check that you have not pulled the cable out some how, a quick look at the throttle body will tell you if the throttle butterfly is closed. Good luck

TimeSert bushes are more reliable than Helicoil and available in a range of lengths to suit the depth of the original hole. Will keep thread diameter as standard if you are concerned about oversize.

Irrespective of firing strokes a 4RT at 1800 rpm will be travelling twice as fast as 2T(or 4T) at 900 rpm ! In regard to gearing, Perce has much more experience than me, but got to say I find my '14 RR 260 really good with standard 10/41 gearing, the motor is much smoother than my '06 and between clutch and the higher gearing I find the bike grips better and doesn't break traction as easily as my '06 which I did have on 10/43. Is the reason that so many of the UK riders find it difficult to find grip with the 4RT because they are on low gearing?

It also depends a lot on the actual Mont that you have and it's set up and accessories fitted. There is not much doubt that the 05 motor as standard was quite fierce of the bottom end and the clutch was also fairly sharp, I had a programmable throttle body on my 05 and found the standard map difficult to ride. I eventually ran a programme (ZOG 3 or 4 from a TC contributer Ferret Flasher) this was a lot softer at the bottom end and was much easier to ride. Change of clutch plates in the following year also made a big difference. Cam change from 2008 ( I think) also improved the motor and my 2014 RR is even more rideable in the low and mid range even with retaining the standard 10/41 final drive gearing. The raptor footrests and hangers are also approximately 35mm further to the rear axle than standard which tends to lighten the front end and move rider weight to the rear. So as I said depending on the bike set up those things may be contributing to the difficulties you are experiencing. Also worth checking the swing arm pivot and linkage, I had a swing arm bush sieze that was making the rear end very non responsive and that will affect traction as well. Good luck.

I also ride on the balls of my feet but have for many years used the CLAKE pro which gives the safety line that you mention, in that fully pulling in the clutch applies the rear brake. That is all I use 95% of the time, however the foot brake is there on the occasions that you want to have the clutch fully engaged and pulling against the rear brake. Regularly saves me from looping the bike.

Hi Marty maybe not the plug? I have always used standard and like Dadof2 have always ridden away steadily until warm. The times mine have been difficult to start when hot (assumming that you are out of gear or have no clutch drag at all) it has been either too low an idle setting or slightly tight valve clearance. I have found it necessary to set valves exactly at the standard setting. Even at the tight end of the .02 range in the manual, it seems to have an effect on hot starting.

Agree that modern battery technology for such a low power demand are very small, the new Li-On units that hold their charge for months and will jump start a Kenworth truck 15 times are now about the size of a cigarette packet !! With the 4RT I think the benefit of a battery would be to allow a much slower and more reliable idle speed.

In my opinion the 4 RT was the revolution, and if the FIM had not backed out of their proposed rule changes I would suggest that the 4RT would be at the head of the pack. As for no changes in 10 years, I reckon that is a bit harsh. I have had ,05, 06 and 14 R.R's and for me the 260 motor is substantially different from the earlier models. The 2014 is much more rideable for the average rider, I always had to drop the gearing on the older models, the 14 I have left standard and find it is smoother and more tractable than the old motor and seems to find more grip. OK not a revolution but a worthwhile development I think. The information coming from our importer is that the 2016 bike will be available earlier than in previous years and that the motor will have more power. ( I interpret that as possibly increased capacity) Did I see around 60 Honda/Montesa machines in this years Scottish?

I have run 4RT's since '05. My first one I did 18 months on and sold to a friend. He gave it a very hard time for the next 2 years before we stripped the motor. The piston wear was only just above the min manufacturing tolerance and no where near the replacement limits,bore wear was also well within limits. Ring gap was however close to the wear limit. My current motor has done 6 years with almost no missed events and still has good compression and uses no oil, however will be stripping soon. Other threads have confirmed long life of the cylinder components, I think quite a bit will come down to air cleaner maintenance and oil and filter changes. How piston wear is so limited in an over square motor when the piston skirt is so short amazes me, it looks more like a tin lid than a piston !! Reckon periodic compression check will give a good guide to service intervals as the motors do not seem to suffer catastrophic piston failures based on time.

You were lucky, when my leg fell off I didn't notice it and tripped over it and broke both arms, only just managed to finish the trial !!!

I don't know of anyone using the Rekluse in trials, however over here a fair number of riders use the Clake for trials successfully. The Dual Clake unit allows you to retain the foot pedal in addition to the hand Clake set up. The Clake dual takes feed from the foot master cylinder directly to the Clake hand control and is therefore compatible with all hydraulic brake set ups. The Clake has been fitted specifically to Beta Trials models

Hi Billy, John probably has most overall experience with these bikes. I have not ridden at those altitudes on the 4RT's however have ridden several of our summer series trials on calm days with temperatures of 43 C (about 110F) without any similar symptoms. The slightly thinner air will reduce the cooling effect over the radiator (even electric motors are de rated above 10,000 ft due to reduced cooling efficiency), so a radiator with greater cooling area (not more coolant) will assist. However I have not noted this problem at even higher temperatures. I have also not needed to run a harder plug, but is a good idea in high temperatures. Assuming rad fan and pump is normal, I reckon number one culprit is likely to be plug however similar syptoms can be experienced with tight valve clearances and is worth a check. My old 06 became hard to start particularly when hot and was traced to tight exhaust valve clearance, correctly set an instantaneous cure. As John says a two stage map may help, however I have always had to get someone to re programme mine (single programmable throttle body) as I am not that computing savvy. Note John says that the standard mapping should be OK at those altitudes so tends to point possibly to something else not correct, Good luck

Hi Billy, You are correct the idle screw on the 4RT does not change the mixture at all, idle or otherwise. It is only a throttle stop that alters the stop point on the throttle butterfly. ALL air fuel adjustment is via the ECU mapping. When you say get more air at the top end, do you mean it is too rich and you want to weaken the mixture or do you simply feel it is not revving out fully? Obvious possible causes of restricted air supply are dirty or deteriorated air filter, the foam is very fine and I think that over oiling with a tacky air filter oil may clog the foam, the book suggests only engine oil and that is all I have ever used. My speedway machines use K&N air filters that are much coarser foam and fitted with mesh pre cleanin elements these do require thetacky filter oil to work well.

HI Ric h, A very steady hand with the MIG well done, it is not easy being that neat when trying to move the gun in a circle, Full marks for that, for others less proficient (like myself) the technique works just as well even if the weld looks like Pigeon S...t !!!!

The new bike was only set 2 clicks out, after first day out I unwound the damping fully, it is better but the set up is so tight it doesnt seem to make much difference at this stage even when fully out. I may drop the shock off and check that the swing arm is not binding. I am at the bottom end of the rider weight average , with the 06, I eventually got fed up with the rear kicking hard over logs etc and fitted a TRP with a lighter rate spring and that has worked well. This time will stick with the Showa a bit longer and see if it will free up. Hopping at the moment hard pushed to get the rear end off the ground at all. thanks for the encouragement !!!

So this is the revolutionary change for 2015 ???? Glad that I didn't cancel my '14 RR and wait for the "new" model. Reckon the whole trials world has gone mad when a new mudguard and sticker is announced as "Improvements" !!!! very happy with the motor on the newly arrived '14 RR quite different from my 06 motor even with ZOG 3 programme installed (softer at bottom end) However the suspension is so tight at present, mainly at the rear, the ride is worse than the 06, hope it will break in before it breaks me !!