triple_x

Thank you for your interest and advice. During today a friend of mine has done some research through a trade catalogue that specializes in Off Road bikes. What he found was this:- KTM65 SX 02 - 09 use 35mm x 47mm x 10mm seals. All Balls make a kit "Part No 57-827A" which comprise 2 oil seals and two dust covers. On paper it looks as though this will be the easiest route, so I will give it a go and report back. So I will fit them in the Model 91 and give them a try before converting the 198A. Kind regards Martin

Hi Can anyone advise? I am disappointed that the standard Betor fork dust protectors don't really do their job (yes I fitted new ones!). OK, they they stop the majority of the muck getting in but are not as effective as the current design on my Gas Gas. So I have been searching the internet for 35mm x 47mm dust seals (similar to the Gas Gas)to replace the standard fittings. I know from the pictures that the Spanish Puma bikes use this system so I would appreciate help in finding a supplier. I have tried Pyramid Parts without success. Further, due to the nature of the design does this new type dust seal replace the top seal(leaving only 1 seal per leg)or do I need to modify the slider to set the seals further down? Kind regards Martin

Hi Point 1 = Fit and forget Point 2 = Engine starts better Point 3 = Engine delivers it's power in a much more usable way. But remember a good rider will still win with either points or electronic ignition. No pun intended by the three points above!!!!! Martin

Very interesting topic and observations (sorry). Perhaps the easiest way is to ban hopping the bike to get a better position. Then as A W advises forward motion will be maintained. There are no half measures if the bike is not going forward it is either stopped, on it's side or going backwards. Martin

Just the stator plate, the flywheel remains. Replace the original coil and condensor with the control box under the tank. Really easy to fit. Regards Martin

This behavior is not new. In the early 70's I was CoC and came across a hold up in one of the sections about half way around the course. Asked the observer what the problem was and he said nobody wanted to ride the section as they were all waiting for the gully to be worn away and make it easier. I simply advised him to call the lowest number, ask him if he had inspected the section, and if so, tell him that he was required to attempt the section when called to do so or get a 5. Given the status of the rider he was reluctant, so I did it. Conversation was not polite but he rode the section cleaned and won the trial. Spectators who heard the conversation commented on why I put up with it and i simply said that "It said more about him than me"! But I got the result, the trial got moving and I could close the section. It happens, its down to how you manage the situation! Martin

When I was riding back in the 60's and 70's we got a five if forward motion stopped. Simple. Surely the physics havn't changed you are quite simply stopped or moving, what is there to understand! On Sunday I rode in a very good, well laid out event, about 60 riders split into 3 groups going to 3 starting places (section). All well and good, until that is we ended up queing behind the bunny hoppers. Boring for the obervers, boring for those waiting who just wanted to get on with it! Martin

Hi I am very pleased with my Electrex set up. After all the faffing about is was well worth it. Of interest was that after fiddling with a strobe and getting it spot on it was back in the position the instuctions advised. I think the confusion is that points are static timing, Electrex advances to the optimum by 13 degrees (I think) and it is this feature that makes the power deliver so smooth and tractible. Well worth the money. Martin

Hi When I got my Electrex set for the Sherpa I faced the same problem. However by installing it as per instructions set screw @2 0'clock (top R/H) to the mid point of the slot it ran ok. Being a bit sad i measured the O/D of the flywheel multiplied it by 3 1/7 (3.1428)which gave the circumference. I simply divided it by 360 (= degrees in a full circle). That gave me the amount of rotation for 1 degree. Multiply that by 24(or what advance you need)which give you the advance rotation. Set piston at TDC and fix a pointer anywhere convenient on the crankcase, mark the flywheel with a felt tip marker and scribe a line. That is your TDC mark. Then measure to amount of rotation for 24 degress (or what you prefer) scribe that dimension anti clockwise from the tdc. Rotate the flywheel to the pointer and you piston should have lowered by the correct amount(use a VERNIER GUAGE to check). The annoying part is that you have reassemble the cover, start the engine, remove the cover and check the timing with the engine running. As said in a previous post at 4k rpm the timing should advance to the correct timing position Good luck, it sounds more difficult than it is. It worked for me! Martin

Instead of worring about the provence and engineering skills that went into the above machine. When will people get serious and ask why the modern Pre 65 bikes that bear no relationship to the original machines are allowed to partake in pre 65 trials. My 71 Sherpa is more original than the majority of Cubs, Bantams, James that I have seen. I am now ducking below the parapet and off to bed! Martin P.S. Sorry out on my Gasser Sunday.

Hi Bike settings are down to your personal choice. I have modified the yokes and had the head spindle rebored and sleeved so that the forks were parallel with the head. I have gone the Magical route and it transformed the bike, worth every penny! Mikuni. On my 80 series engine with ported barrel the jetting is Pilot 37, Needle Jet 182 N-8, Jet Needle 5F21, Throttle valve 2.5 and Main air Jet 2.0. raised the needle 1 notch from standard Bear in mind these setting work on my bike and suit me. Woody is right you don't need to play around with the steering for the SM Series, however i preferred my bike after the yokes were modified. See you in May at round 1. Regards Martin

I spoke to the Greeves staff on Saturday and they were very informative and helpful. Just remember, a small company is taking on the might of GAS GAS, BETA et al. My personal view is that they are at least attempting to make a BRITISH trials bike and need support for what in this day is a brave endeavor. Regarding the show a great day but I just felt it needs tidying up a bit. Martin

Talk to Elextrex world, they supplied mine and it has worked perectly from the off. Martin

For what it is worth. If you wish to keep the original castings, then go to a specialist welder who will reset the casing, weld the cracks, clean them up so that you are back to square one(with servicable castings that looked as they did) before the damage. My model 80 suffered similar damage was repaired professionally and looks as good as new! Personally I think that some of the methods avialable, apart from Aluminium welding are just get you home fixes that will fail in use if their life is extended. The choice is yours! Regards Martin

Have a look on AMAZON for the Clymers manual. I just boought a new manual Dirt Bike Collection: Bultaco, Ossa, Montesa Workshop Manual (Clymer Collection Series) for

Hi I have no info on your engine but would have thought if space allows, then 3 bearings are better than two. Talk to Bultaco uk they will have a much better idea. All the Sherpa info they provided was spot on. Regards Martin

My M80 has 3 main bearing which according the the manual is standard for the year. Simplest way to remove all bearings in to put each crankcase in the oven @ 145 degrees for 15 minutes and they will simply drop out. Reassembly is just the reverse, but put the bearings in the fridge prior to dropping into the heated crankcase. Oh dont for get to put the crank oil seal holders (without seals) in place the stop the bearings droping right through. Finally put a pepperoni pizza in the oven to get rid of the oil smell. It just keeps the wife happy! Have fun Martin

Hi I use 60-1 and my pro runs fine. Personally I worry about reducing the amount of oil to 70-1 I just think it is too little to provide sufficient lubrication. Am I right or wrong? Who can say, I just feel comfortable with this mix ratio and don't think there is any gain from running less oil. But I always use Super Unleaded (Shell if I can get it). Rather that listen to our personal views just phone Gas Gas UK at least you will get told what the manufacturers recommend. Martin

Hi I use 5 weight in the winter and 15 in the summer. That's what Sammy Miller told me and it seems to work! Regards tha amount, well I put in the amount speced in the manual and just kept adding a touch more until they softened out at full compression without bottoming. Just trial and error but beware too much will blow the seals. I can't ride for toffee but the front end certainly improved as last season progressed. Regards Martin

I have a Model 80 motor in my Sherpa with Elextrex world ignition. I set it up and strobed it (what a pain)to make sure it was timed as per manual. I have since retarded it to get it to respond in the way I prefer. Nice and soft at the bottom end but still with enough power to out perform my abilities. As Woody says just ride and adjust it to suit you, not what the manual says. I will be at the Greensmith so if you can make it and want a go afterwards just ask. Regards martin

Hi Thank you both for the tips. Bike seems sound, all there and starts well. Just need to make sure I have the settings and give it a good clean and service. I bought as an alternative to my two Sherpa's as quite a few of the local trials that run twin shocks appear to be set out out by people who have never ridden one! Kind regards Martin

Hi I am looking for general info on the above and any help would be appreciated. Fuel Oil ratio. Fork Air Gap or mills per leg. Plug and gap. Kind regards Martin

Hi I am rebuilding the above engine for a colleague. Is the gearbox timed in the same way a Sherpa is? For example the Sherpa selector drum is positioned with the cluster in neutral and this is obvious, as the straight side of the diameter with the selection indents is to the rear and set vertical. I am sure I can work it out but it is 31 years since I have had a Cota engina apart and that was a 250 and i always appreciate any tips. Thank you Martin

Hi I had a similar problem with my VM26. I had a 35 pilot and it would only run with the screw 1/4 turn out. I changed to a 37 and the bike runs sweetly on around 1 turn out, and starts easier when cold as well. Hope this helps but bear in mind my Sherpa is a 250. Martin

Hi Well nearly finished. It has done two trials and is getting better (I wish I was). http://lh3.ggpht.com/_BIYAknJT7JM/S9xiSKKS...20/P1010772.JPG Runs a lot better with the new rear box and have just modified the yokes and fitted a 48 rear sprocket to try out. Have managed to get hold of a barrel of the correct type but need to heat it up so that I can twist the liner by about 3mm to line up with the ports. Regards Martin C:\Users\Owner\Pictures\bultaco 09\P1010772.JPG