no balance

Hi, unlike Bultaco I can't find any books on Ossa's, I'm mainly looking for info on the Mar range, so if you know of anything (in or out of print) I would be greatful if you could let me know the title or ISBN number. Cheers in anticipation ! NB.

I think the main difference is trials bars are straighter. You do see mx type bars on trials bike and to me they look a bit odd, but I suppose it's personal preference.

Hi, sorry for the slow responce guys, haven't looked on TC for a long time. Truth is I never did get the electronic ignition to work, I sent it back to be checked for a fault but was told it was fine and the most likley cause was the crank case oil seals or a carb issue. I did get it to run again using the old Motaplat electronic ignition by fitting another HT coil. I also replaced the new Mikuni carb because of over fuelling issues, no amount of jet changing etc made any difference, so I fitted a old 70's Mikuni (the bolt on flange type) that I removed from a 250 Bultaco Sherpa years ago and it's run spot on ever since, and it's now my bike of choice. Plug colour is good and it starts cold or hot really well, it pulls from nothing so well, cutting down the use of the clutch in sections. I still don't know if the new electronic ignition will now work on the bike because I haven't tried it, I did try to fit it to my other Mar but when I pulled the fly wheel it was the wrong type, sods law!!

Been looking at the ignition again tonight and I think I've sorted it, after returning the stator plate back to the position it was supplied in, I noticed it had another set of threaded holes next to the one's being used, so I moved the fixing bolts into the other holes and moved the stator plate as far to the left as it would go, refitted the flywheel and cover and started it, the differance was huge and it was back to how it was before the old one packed up. I'm hoping all I need to do now is strobe time it to get it spot on. I'm only used to timing bikes with points and can't find any marks on the flywheel or case to use for strobing it and the flywheel doesn't have a hole for a timimg pin/tool. So if I use my DTI gauge and set the piston at 2.5mm btdc and put my own marks on and strobe it with the engine reving fast to get full advance, would I be doing it by the correct method?

Thanks for your reply, but his ignition comes pre-set and the fitting instructions say not to move it from that setting!! it can be advanced and retarded and doing this has made no difference. As for timing marks for strob use, I will have to check that out. Cheers.

Hi, last time out on the Ossa Mar it decided to pack up, after stopping, I tried to restart it but it would only kind of four stroke with the throttle wide open. Back home and the bike cooled down, it would start and run ok for a few seconds and then start four stroking and cut out. I changed the coil with a good spare one I had but still the same, when checking the spark it was very weak. So I ordered a new electronic ignition to replace the notoriously troublesome Motaplat electronic system, with the new ignition fitted the bike started first kick, the problem I have now is the bike lacks throttle responce to the point that it would be useless, on the old system it was quite lively for a Mar and equally as good as my Bultaco M91, any suggestion as to why it's not what it was would be most welcome. Cheers.

Hi Andy, in your first post to this topic you said you can get two trials bikes in your Caddy, have you got the Maxi or the standard size?

Hello, you could try Rex Caunt Racing 01455 848 287, they sell an alloy cylinder kit which I think is ported for trials but you would need to check that with them, not cheep though £420.20. They also do other stuff for trials Bantams and are very helpful. Cheers NB.

Hi, I think you will find that models 242 304 307 308 309 and 311 use the M39 engine so this should increase your chance of find the part you need, have you tried Ella Stone Off Road ? Cheers NB.

It depends on how much money you want to throw at it, personaly I wouldn't spend out for full electronic on a three speed engine, as we all know the most competative Bantams have four speed boxes with second and third gear swopped around, so yes would have to agree that a Electrex World full electronic ignition would be the way to go on a four speeder. Cheers Nb.

Hi Tony, Simple answer is yes you can run with the other coils removed. The timing is 1.5mm btdc (best done with the head removed) or 2.5mm btdc if using a Todd high comp head etc. You could also look at fitting a Rooster Booster Junior type module, so you can do away with the condenser. I have one fitted on my bike and it works very well. These modules can be found cheeper at places like Garden Machinery Repair places or Ebay, I have seen them as cheep as £12.50. Cheers, No balance.

Many thanks for the input Guy's, and I do have to agree with Charlie regarding building a bike that is British, I was thinking that doing it my way was going to be the cheapest option, but by the sounds of it maybe not. When the actual build gets underway I will try to post some photo's of the frame and engine mods etc. Many thanks, NB.

Yes, I know what your saying Woody but I was thinking about 32mm jap ones, with a strongly fabricated fork brace to take the flex out. In My opinion the larger diameter front forks can look it bit out of proportion on a little Bantam, as long as the compression and rebound works well I would be quite happy with the 32mm size, unless there's a good reason not to ? NB.

Hello, just in the process of gathering parts to build another Bantam trials. I have found a set of BSA C15 forks and was wondering if these are any good for tricking up with internals from say a jap bike ? if so, any suggestions for what to look out for, advice or info much appreciated. Many thanks, NB.

Thank you for the recommendations/advice, OTF is correct and after speaking to the Mot tester yesterday I will be taking his advice, which is to have the following:- Speedo, any type. Horn, any type, bikes after 73 (I think) have to have a continuous sound. Brake light. Number plate, it should be full size but that just would't be practical ( would it officer !!) I plan to make all of the following items as quick detachable as possible.

Thank you for the responses, but I should have made myself a bit clearer, I would like to know approximately what speed I'm doing, due to the local traffic police being, like dog **** used to be......everywhere !

Hello, I have a Wasp RT3 with a unit 500 Triumph engine in and would like to put a day light MOT on it. Has anyone used the mountain bike type speedo and horn with any success, if yes, what make are they. I have looked at a few on line but they seem to cheap to be any good !! but I would prefer a wire less one . I will have to fit a small battery for the stop light, so plan to used a led bulb to cut down on power drain (the electronic ignition has no charging provision), I could also connect the horn to it, so it only leaves the speedo to sort out. Regards, NB

Hi, I remember reading an article in Classic Dirt Bike about a 1967 Bultaco Model 27 (registration, 548 UZ) owned by Benny Crawford, it was in the first issue. The guy that had it then was the proprietor of the Yamaha TY spares shop, Trail and Trials uk, John Cane. Regards, NB.

Unlucky Woody, hope it didn't cause to much damage. I think I've worked out how it's done. After having a close look (with my glasses on this time!) I can see that it has a thin cover over the top of the cap which hopefully I can get off with out damaging it, getting it back on will probably be the difficult bit. Still open to any good ideas for dent removal though. Cheers No Balance.

Can anyone tell me how to remove the hinged alloy filler cap on Homerlite petrol tank, also on the same subject any tips on dent removal would be most welcome. Regards, No Balance.

Hello, all of the above is good advise but I found the main reason for the front brake not working on the ty mono's is the bracket that the outer cable fits into flex's under hard braking(not the handle bar end the other end). Get someone to pull the front brake on(hard) while your looking closely at that bracket and you will see it flexing !!!!. I re-fabricated this bracket in much thicker steel and it totally transformed the braking. Hope this is of some use. Regards No balance.

Hi, yes I would say the Miller mid section is a form of silencer, doesn't have to have E number or any of that old rubbish, as for your frame, the number on the head stock would start SM so it's probably a modified M91 frame, looks very nicely done what I can see of it. I think the Miller frames were lighter/stronger than the standard Bultaco frames and bronze welded, with a nickel or chrome finish. NB.

Hi John, I too am looking for a good tank sealer for fibreglass tanks (x3 !!) I've only found two that sound suitable Caswell and Slosh, opinions on different products would be much appreciated.

Looks like the mid box is the new Miller products type, so you could try repacking it to quieten it down. Most MOT stations that are happy to issue day light tickets look quite favourably on competition bikes, so take it to the tester, start it up and ask if its acceptable! None of the original type end sections ever seem to fit well, I would just clamp a straight tail pipe on if it's loud for the MOT then remove it when passed!!! Your frame, is it a Miller high boy or a modified early M91 frame ? Regards, No balance.

Hello Pschrauber, appreciate the input, your second suggestion regarding the shoes (in England pads are for disc brakes) is one that I have been giving a lot of thought, but not sure if this is something that could be achieved in the home workshop or can it only be done by a specialist. It makes sense to have more surface area of the shoe making contact with the drum. Many thanks No balance.