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?
OK, this is an advantage, with the points you have only one timing!
Three question to the electrex ignition is it only the stator you change? or the complete ignition unit with stator and rotor? are their also a power supply added for lights f.e. ?
Just the stator plate, the flywheel remains.
Replace the original coil and condensor with the control box under the tank.
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!
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.
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
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!
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.
went to the telford show a crackin day out pick up parts that i needed for my bike saw a load of nice trials bikes to view one bike i thought was a load of crap and a copy of the new sherco was the new greeves trials the way the staff were there around the bike they were well up they own a*** you would have thought that they made a product that would change the world it just seam s to me all they do all day is work in a design room taken idea s of other bike s they must be so good of a bike no magazine has done a review test on one and i dont think they could keep up with the others on the market myself i think they should call it a day and apply for a different job.......... i heard del boy is looking for someone to sell his copyed merchandise ...........
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.
I'd like to hear some evaluations from those that have used them.
It seems to me that a 325 has plenty of power, but I wonder if an ignition with an advance curve would noticeably widen the power band by letting the engine rev higher.
That would likely rerduce the need for shifting in a section.
Talk to Elextrex world, they supplied mine and it has worked perectly from the off.
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.
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.
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.
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!
Before the 1st round of the Sammy Miller Champs this year my last trial was the 72/3 Perce Simon (a trial I had rode in every year since 1966).
I bought a wreck af 71 Sherpa last year and did a ground up rebuild.
I can throughly recommend this series, as each trial is around 30 miles (with road work) with 30 sections, which gives us wrinkly's a break to get our breath back.
Whilst at 62 after a 37 year break, yes I have found it hard.
But the countryside is superb, the fact that I am relearning forgotten skills, riding motor bikes (not pogo sticks) and the friendship of the fellow riders is as I remember it in 60-70s.
I have competed in the excellent Ringwood Thursday evening summer series which I found taxing as 4 laps of 6 -7 sections in 2 .5 hours was hard work but every time I left with a smile on my face.
To me trials without road work is not the real thing, but I accept that trials must adapt and so must I. Thank you everyone that has made my enjoyment possible.
I cannot wait for the next round this week end at Builth Wells.
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.
Sherpa fork dust seals
in Bultaco
Posted
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