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alan

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Everything posted by alan
 
 
  1. Blimey does nobody workaround here ;-) ??? I am not sure about the ATF for the clutch, the oil is there to lube the chain and the clutch bearing (which only moves when the clutch is pulled), I prefere a lubricating oil and use 150 ml SAE 30 with out problems. There is hollow tube through the middle of the gearbox drain plug which is sealed with a screw in the middle of the plug. Remove the screw and fill until oil comes down the tube. Again I use SAE30
  2. Having just rebuilt my engine again...... what is the view on oil and oil filters ? Mineral, semi synthetic, or fully synthetic.Has anyone had experience with oil filters on the return line ? I have looked at the DC motorcycle element type and the trials bits screw on type. any suggestions/recommendations
  3. the problem with the trial and error approach is that you have to take the casing off every time. I have found the best way is to back off the springs until the clutch just slips when you kick the engine over, then wind them back in 1 or 2 turns. As a test i put the front wheel against the wall, with bike in gear, i can stand on the kick start with all my 10 stone without the clutch slipping. don't forget the clutch will slip more easily when the oil gets hot. Good luck, this is a black art, once you have got it working leave well alone!!!!!!!!!
  4. The problem is that you have to somehow mount the stator so that it is concentric to and in line with the rotor. On bikes like C15 's you can use the alternator stator mountings, but cubs mounted the alternator stator on the primary chain case. You could in theory mount to the primary chain case but you would not be able to adjust the timing or check that the rotor is not rubbing on the stator. The only sensible way is to mount to the crankcases. This is usually done by welding aluminium pillors in the right places. The pillors have to be 120 degrees apart, in the right orientation (or you will not be able to get the chain case cover back on) concentric to the crank, on the right PCD and the right height. The way it is usually done is to split the crank cases, put the casing on the milling machine, spot face flat pads to weld the pillors to, drill through the pads in the right place. The pillors are drilled and tapped so that they can be bolted to the case from the inside. After the pillors have been welded on, put back on the miller and machine all the pillors to the correct height. While you are at it you may as well mod the back of the housing so that you can change the engine sproket without a massive strip down job. Then all you have to do is rebuild your engine !!!! Once again Alan Whitton can do all this for you. I have heard of this been done from the outside with the engine assembled, using a dremel to create the pads, threaded pillors locktited in, but a lot of skill is required to get this right and there is a risk of swarf in the crankcases. I beleive someone is selling ignition kits designed for cubs that does away with the crankcase mounting, i have not seen one yet so cannot comment But in my opinion, do it right first time !!
  5. Totally agree, from experience it is cheaper to get the right one first time. The kart ones are designed for running flat out at high revs, the HT coil has fewer windings (lower voltage spark) and often little or no built in advance. Various HT coils are available with varying degress of advance, guys like Alan Whitton will make sure you get the right one for the job. At the risk of sounding like a socialist, you may pay a few quid more but you will also get a lot of free sound advice thrown in and a least you are supporting a fellow enthusiast. Go on you no it makes sense!
  6. judging by your avitor you put it in the wrong place
  7. Featherlite eh .... don't they come in a pack of three ? pre lubricated if i remember correctly ... have you tried the ribbed version ? it is supposed to increase the pleasure of riding.
  8. The standard clutch struggles to cope with increased performance unless carefully set up. The problems start when a smaller engine sproket is fitted to lower the gearing (a common Serco mod). This means more strain is put on the clutch as the engine turns over faster on the kick start. Heavier springs are usually fitted to overcome this problem. This puts more strain on the cover plate, especially the aluminium ones (another common serco mod). The surflex friction plates are too thick as manufactured but Serco machine them to the correct size, (it is not unheard of for the end plate to fall out when the clutch is operated if unmachined). The lever can be lengthened by welding an extension on, I made a longer lever with a bigger forked end to accomodate a barrel nipple. I am not really sure it was worth the effort as I rarely use the clutch in sections, but it reduces the strain on the cable. I am not sure about the "drain level holes". I have heard of holes drilled thro the crankcase to the primary chaincase as you describe, but as i recall Martin was an advocate of running the clutch on a small automatic transmission fluid to prevent slip. He also recommended fully synthetic engine oil which would not aid clutch grip. Could the holes be part of the breathing system? The crankcase breathes thro the cam bush into the inner case. There is a small hole to return oil back to the sump. Have you got a breather on the distrubutor blanking plug ? if so maybe the drain holes are in the inner case ?I would be suprised as Martin usually recommended blocking this hole up " lets more oil out than it allows back in". It is easy enough to take the primary chain case off and check for the holes, it there aren't any i would suggest putting in around 150 ml of straight SAE 30. As for compression, 9:1 is as high as you should go for trails use, some of the more competitive cubs are running 7:1 for more bottom end grunt but usually big bore engines as well.
  9. there is a nice looking one on Ebay just now. It is ridden regularly and competitively in the Yorkshire classic series.
  10. Many competitive cubs have short exhausts as you describe. Conventional wisdom would say a longer system should help power at the bottom end and vice versa. I have R cam, high compression and short exhaust it is a bit flat until the revs build up .. i guess you take your choice to suit your riding style. You can lengthen the clutch actuating arm. You need to drill a new hole in the casing for the cable to make everything line up again (otherwise you will lose the benefit by having poor angles of pull on the cable). You will lose a small amount of lift on the clutch pressue plate, but if all your plates are flat and springs evenly adjusted you can get the the clutch to free without dragging. I beleive Alan Whitton does a four plate conversion that allows you to run lighter springs without fear of slipping.
  11. To check for an air leak you can try holding a smoking cigarette close to joints with the engine running. The smoke will be drawn in if there is a leak. For non smokers, i have read that you can play an un-lit blow lamp around the joints with the engine running off choke. If the engine picks up it suggests that the gas is been drawn in to cure the weakness. At you own risk though...............
  12. Could be wrong,but it looks a bit retarded to me (assuming you have a high comp motor with an r cam). If I remember correctly, a good starting point is to mark a line on the stator on an 18mm chord from the corner of stator coil. Then set the mark on the rotor to this line on top dead. This gives a static advance of 20 deg BTC. There are PVL set up instructions on tinternet.... google PVL it's 4 or 5 pages in... but it is there some where.
  13. I beleive it has been done by Mike Grant with the help of Martin Adams (serco). In my view, although it may save a little weight and reduce the centre of gravity, I am too fat and not skilled enough to notice the difference. On a technical note, I am not sure how the oil pump is primed ( a little head is always good!!!!), and although all modern stuff have the gears running in the engine oil,they also have a proper oil filtration system too.
 
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