johnjsy

This is the little end spacers I made.[ attachment=17257:image.jpg]

Hi everybody,I am following this with interest. I did see somewhere that Kevin Breedon Racing has a large range of Pistons,may be worth a look. A request. Does anybody have a used but not very good std: 85 mm piston ? To explain,I have a relatively rare 1974 only M 173 motor,basically a MK 9 Pursang,but it is a 346 cc made for grass track racing. I managed to get a barrel from Spain,but it is 85 mm bore & will need a new liner at 83.2 to get down to 346 cc as original. I would like to run it a bit to see all is well & set up the clutch before getting the new lined job done.When finished I will sell it on as I have no competition chassis of any kind to put it in. Recently I have built a hybrid Alpina -- Sherpa M92--M99. 326cc now in my road bike.Goodness me,talk about torque ! I have used a Pursang gear set,lovely to use on the road. I too had the little end float problem so made my own alloy spacers from dural. I fit them with a close 2 to 3 thou clearance. One other thing, I put the crankshaft in the cases these days,no bearings,bolt together with a gasket,then measure the cases to crankshaft gap. Calculate half that then make up shims to that size. When the first case is heated to the drop in the crankshaft it then sits on the shim. This way I can get it to be as central as possible. On the timing side I use a roller bearing,so easy to assemble. I hope this is of help,regards,John.

Yes,these things can try the patience somewhat ! I usually drill 3 very small holes equidistant close to the edge,very carefully then screw in small self tappers. Using 2 pairs of pliers just ease up a little at a time.If very stubborn heat up the alloy leg good & hot with a heat gun. Just go easy,don't rush,it can be a pig of a job! Putting new seals in,coat the outside with Vaseline,this stops the alloy from corroding.Be sure the fork leg is really clean first,though. Sealey tools do a very useful seal puller tool,well worth having.Not too expensive,the number is AK 7000. Mine has been used many times. Let us know how you get on,John.

Hi Andy,the red wire is used for a horn,but beware,the current is AC,so you will need the correct horn. A DC (battery) type will not work.I assume the bearings you mention are taper roller? They can be really tight on the steering stem. I put a thick piece of alloy on a small gas ring then place the new bearing onto that to heat up. 3 to 4 minutes should do it,the bearing will slide on quite easily.Have a long piece of tubing ready to tap it down if it needs a little help.Hope this helps,John.

Hi all,a most interesting topic to follow,but a slightly off camber comment from me. Other countries have much simpler & better registration systems. For instance with your first vehicle in Switzerland you are issued a number for life.Change your vehicle,you retain your number.How easy is that ? How sensible. Regards,John.

Hi floydbassman,enjoy your bike & this site,loads of information here for those who need it. I bought a new TFS when they were current. Brilliant to ride on the road,they steered so well,would never do anything nasty to you,even on nearly flat tyres. Mine had a very slow even & steady idle,that's what I remember most. Often wish I still had it.Regards,John.

Hi Johng2, all the above is sound advice,but if it was me in your situation,lube all cables plus the chain. Why ? Preventive maintainance really. A stuck throttle at the wrong moment & you are running into the back of someone or worse still something solid. Broken leg or arm or worse. That's their or your Christmas ruined,so please be sure the cables are in the best of condition. Also,I assume your crash helmet is not on its last legs as well ? Hope this motivates you a bit !! John JSY.

Hi Nicky,that is to my mind piston noise. When chasing a mechanical noise I put a long screwdriver to my ear & touch on different points on a motor to home in on a noise. A long piece of rod or even a thin piece of wood should be worth a try. I have never done an Ossa,but plenty of Bultaco's & the Mahle Pistons are always stamped with a + or - with a number. This is a guide for final hone to be above or below the overbore size. This is critical,it must be right. If you still have the original piston check for the numbers on the top,then see if the new piston is marked the same. Just a thought,if the new piston is a Wiseco,they need a much greater clearance as they are forged & will seize from cold if a too close clearance is used. Let us know how you get on. Hope this helps,John.

Greetings Larry! John

Hi Sean 65,go for a Sigma 509,a couple of notes more than the dead cheap ones,but well worth it. Dead easy to set up & reliable. I have 3, on 2 Bulto trail bikes, & on my Bulto road bike. Plenty to see on Ebay. Hope this helps,John.

Hi all,this always makes depressing reading,but not a problem where I live.A little lateral thinking helps,right? This is what I would do.Assuming the garage/store is alongside your house with wooden doors or supports from the main structure.Panel the entire door/s on the outside with sheet alloy or steel,using plenty of coach bolts with decent washers under the nuts inside. Next,dig a bit of a trench to lay a plastic pipe from just inside the garage door to somewhere just inside the house. This is needed to get a couple of insulated cables safely out of site from house to garage.Next,purchase a Wasp of similar cattle fence generator--you can see where I am going on this,now?--.These things make a bit of a ticking noise,so inside a cupboard or under the stairs they should not be heard.One wire will go to earth,the other to one of the coach bolts under a nut & washer,nice & low down & hidden would be fine.If there is a window with nice strong steel bars,no harm in connecting to that as well. I will admit,quite a lot of work,but a couple of mates round on a Saturday should get most of it done. I do see one problem though,children & pets. Best then just to panel only the top half of the door where the lock is,move it higher if necessary. If at any time a quick dash to get screwdriver or whatever is needed,switch off first.Sooner or later,you will forget!! Anyone out there done something similar? Do tell us!

Hullo Rob M,I may be able to help you. First off,the head may be warped a bit from uneven tightening. Put a little fine grinding paste,plus a little light oil or paraffin on to the head to barrel sealing face & lap the joint to get a perfect even contact all round. Be extra careful not let any get onto the piston or down the side of the bore. Cleanliness is of the essence here! Next,find a piece of paper or card about 4 inches square-- not critical-- then draw a nice circle. Put a dot or an X at 10 o'clock then 2 o'clock then at 4 then 8 . O.k.? Next one at 12 a bit higher up then at 6 down lower. You now have a pattern of the cylinder head studs. I now give you the tightening sequence,put number 1 by 2o'clock --2 by 8o'clock--3 by 4o'clock--4by 10 o'clock--5at the bottom by 6 o'clock & 6 by 12 o'clock. I have a low reading torque wrench & start off at 4 ft lbs & go up in steps of 2 ft lbs. Studs one to four should end at 14 ft lbs & five & six a bit lower at 11 ft lbs. I have been doing it this way for years on many different motors with no problems. Just to mention,when taking off a head,release each nut a little at a time in the same sequence,also I assume you have the correct thick washers under each nut? If not,try & get some,or make some,it is important. Hope this helps,John.

Hi Larry,it is possible to renew the flattened ball bearing,I have done 2 of my 5 bikes. Scribe very carefully from the centre of the ball bearing round to the back to get a good centre pop pretty much exactly behind the bearing. Go slowly,check often. I then use a cordless drill on very slow speed with about a 2.5 drill to make a start.It is difficult to make a start because of the round shape of the metal,the drill tending to skate off. When a start has been made,transfer to a mains drill with a 3 or 3.5 drill to go through to behind the bearing. I use some cutting fluid as the metal is quite hard.When finished drilling a sharp rap with a pin punch will easily knock the bearing out.No punch? Cut off a couple of inches of an old spoke & hold in a pair of pliers,or a hardened masonry nail such as an Obo will do,but grind the point off flat first.I found a replacement bearing in my tin of assorted ones collected over many years,so I have no idea of the size needed. Just check the old one with some calipers then find a new one about the same size. Just to mention while I think of it,the correct size of one in the centre of the clutch release rods is 5.5 mm. In Motion have them. Hope this helps,John.

Hullo,I like that! A suggestion if I may,contact In Motion as they have the correct shouldered bolt & nut for sidestands. It will make the job a good un. My Metralla had no stand,so I made a side stand out of a bicycle handlebar. It works fine but I am very cautious of parking on a windy day. To make & weld on some brackets would entail stripping out the entire bike to get the frame upside down to do the job properly. One day,I suppose. Hope this helps,John.

Hi millerme,& welcome.I had a M10 from new when they were first available & like many others wish I still had it.As for feet up fun,not at all sad. You & many others are keeping the spirit of Don Paco alive,which is to me very important. Do I qualify? Er:Yes,I hope so. I have a 159 motor in very good order, but no cylinder or head. I keep looking but none ever seem to come up for sale. Meanwhile,I have 5 others to keep me busy,all are registered & get used. They are 2 Alpinas 1971 &1974 - Lobito 175 from 1971- A Metralla 1967-& a much modified 1974 Pursang with a hybrid M92 & M99 326 cc motor fitted at present. In recent years I have twice visited Ivan Cirre & Romero Motos in Barcelona & seeing what they are doing is really encouraging. Don Paco,your legacy is in good hands. Siempre Pulgar Arriba-Thumbs up Forever. John,jsy.

Hullo Trum,my usual No: 1 item to check! Strip back an inch or so of any of the under tank wires. If discoloured or black,replace them all--pronto! Why,because the conductors are well past it & are becoming high resistance & will not pass anything like the current they should. If you can get it,use tinned wire,it is the best. With new terminals,crimp first,solder to finish.It is bad practice to only solder,vibration will cause the joint to fail. Years of fitting/ fixing radiotelephones has taught me that dodgy wiring & connectors are the culprit most times. Keep us up to date on your progress. Hope this helps,John.

Bonjour Richard,je suis John,dans le Isle de Jersaise.Hullo Richard,I live in Jersey,Channel Islands,not too far from you. Our classic and modern club has a 2 day trial on March 7th & 8th if you would like to come over to watch,or take part. We had a few riders from a Brittany club last year,they enjoyed themselves. We do get bikes for sale sometimes.Here is an email address to try:- bob@bobsmotorcycles.co.uk. Look at www.jerseytrials.com to see more of what we do. Hope this helps,see you in 2 months? Mes salutations,John.

Hullo Hencam,a rod brake is the best for feel & is nice & positive when correctly set up. If not being totally original is no objection,a Pursang hub would give you a sprocket on the left with brake drum on the right,job done! Er,not quite. Most of these had a chrome surface direct onto the alloy & over the years most of them had peeling off troubles. The answer is a steel insert. You could use a Metralla hub,but these are rather big & quite heavy,also a road M.Z. Hub would do,but it uses a cable although that would be short & on the same side. I think the very early Lobito had sprocket & drum is on opposite sides,this could be the answer if you can find one. For me,I much prefer left brake. Most people these days have a car that is with an auto box & use left foot braking,I do so to be on 2 wheels is a follow on from this. Hope this helps a bit,keep us posted on any developments,John.

Hi,an interesting carry on,but I have 2 things for you to have a look at. Your picture shows the crankcase behind the points plate in a bit of a state. If it was mine I would remove the points plate & give the casing a good scrub with Fairy power spray, and a stiff toothbrush. It is a cleaner for ovens,& pans etc:but do wear gloves,it is rather nasty stuff for skin ! It may take a couple of goes,then clean thoroughly with hot water. Why do I tell you this? Because I think you have high resistance between 2 aluminium surfaces. Next,strip back an inch or so off one of the wires terminating up under the tank. If blackened or discoloured at all,replace all 3 or 4,whatever you have,with new tinned wires.I say tinned,much better quality than bare copper. I accept it is fiddly & time consuming at the points end,but do it as quality electrical contacts is the only way to go for reliability. Finally,put the condenser up under the tank as often mentioned in these forums,it is well worth doing.Hope this helps,John.

Hullo Nigel,I have a book,Sherpa,the story.Page 42 says 6 speed motor from 19912885-B onwards also cylinder increased by 1.8 mm & square section rear fork introduced. Total production is 198B 270 & 199B 1778 . Hope this helps,John.

Hi bult360,I have had some Amal parts in the post today to re-build a MK 2 for my Alpina. The needle is a 2B1 & needle jet a 106 . Very quick service from Burlen fuel systems. I have had enough nonsense with MK 1's over the years,& I think the best use of them is a new career as fishing weights!!! However,I do know that they can work as the designer intended,sometimes. The new needle has 5 grooves,hope this helps.John. E

Hullo all,I have been following this all along,loads of good advice given.I think most riders will get a difficult clutch at sometime.Yes,I had one recently that refused to behave.Here are 2 additional things I do. I put the centre hub in the smaller of my lathes( an Emco) then turn by hand slowly with a cutting tool put in backwards-- so as not to cut-- just touching the 6 mm studs.It is then an easy job to gently bend each stud with a short piece of tube to get each one exactly in line.It is amazing just how far out some of them can be! My second bit of " fine tuning" is to check the half round guides,( for need of a better word) the inner drive plates bear against. If grooved or indented at all I carefully dress with a diamond file. The end result is a nice smooth non grabby clutch. Hope this helps,John, Island of Jersey.

Hullo scot taco,I have just read your Sherpa gear ratios posting. I have completely re-built 2 Alpinas in the last 3 years & agree,the ratio difference to a Sherpa box is not too great,I think you will be O.K. At that. One thing to mention however,when replacing the crankshaft main bearings it is a good idea to use C3 rated bearings.These are extra clearance ones,& worth fitting because 2 stroke motors run quite hot on the main bearings.They are only a few pennies more expensive than standard ones. Finally a question,if the 175 barrel is not going to be used,is it avaiable for sale ? Can you p.m. Me on this. Thanks,John JSY .p.s. The bearings I use are SKF Explorer 6205/C3

Hullo Woody,I think that sometime in the past the thread has stripped & tapped out to a bigger size. You don't say whether it is just one or both with this problem? M9 is a standard size but not one I have come across very often. The pitch would be 1.25.If you could find a drill that fits with just a little clearance I can look up on my taps & dies chart to see what is it most likely to be. Either MM or Imperial will do, it could be MM or Whit or BSF or UNC or UNF. Hope this helps,John.

Hi,try this.Spark plug,what gap are you using? Try down to 15thou or so,I say this because the coil may be just able to put out sufficient voltage for a short time when cold.If better,try a wide gap,if then worse suspect the coil.One more thing,( I found this 20 years ago servicing radio telephones) old wires carrying current,strip back an end and see if the copper core wires are blackened or discoloured ? If so replace right away,it is quite literally shot. Replace with tinned core wire,it is the best.Vehicle Wiring Products carry it. Also be aware old soldered joints are suspect. After 20 years or so solder joints start to deteriorate with trapped gases & oxygen from the original melting process.From the outside the joint may look fine,but inside it is suspect. Re-new & re-make all joints & this will eliminate any problems on this side of things.Hope this helps,John.