I have a Norvin which has only been on the road for about 500 miles, the engine is built up from a group of parts that I bought in 1991. It is proving difficult to get reliable gear selection, I have played with the selection mechanism and have now got reliable 1st gear selection. This is important as jumpng out of gear when pulling out into traffic can age a person quite quickly. But it jumps out of second when changing up from 1st, jumps out of third when changing down from top, and will only hold top by pressing the gear indicator foreward after useing the gear lever, at which point there is an audiable click as the detent plunger enters the notch in the camplate. The 'box has a very early camplate G32, this I belive was changed to G32/1 after about 30 units, and susequently changed again to G32/2. Can anybody tell me why? What is the practical differences, do G32 units work? Or would I be better off ditching it for a new model. The selector arms were new, but needed extensive fileing to get them to fit. Ok guys what do use advise?
Gear selection problems twin
- Thread starter jim burgess
- Start date
Follow the instructions in Richardson ,make sure all the springs bushes and components are in good condition ,pay attention to the plunger G35 and its spring G36/1 we lost a race last year when the spring (renewed every season) cracked and wound on itself to half its length. make sure the ears on G61 are square. Experiment with the cover screws if it works better when some are loose then there is distortion that may be due to the wrong adjustment in the footrest bolt distorting the G50 adjust the E80 nuts on the spacer to a glide fit.My last bad cover had been twisted and needed filing (dont forget its not an oil tight cover so a little gap will not matter). give the camplate a talking to with a masonary drill if you like but generally just take your time setting it up the bits that wear are not expensive
As far as I remember they works changed the selector plate because they were unhappy with gear selection. So I would think changing the plate if only temporarily (for checking) against another one would be a good idea. On my brothers twin many years ago the bike kept jumping out of 4th continiously. we finally gave the engine to Bob Dunn to rectify the fault.IIRC he has a dummy gearbox to check the gearselection on the bench. in the end it turned out that there were quite a few gears made to different tolerances over the years and that 4th was only engaging a couple of thou, good enough for cruising but not for accelerating. After finding the fault and rectifying that fault by shimming/grinding the gears, the box worked perfect ever since.
Last year I had a right old time with the gear selection on my shadow after fitting new helper and centralizing springs ( the ones inside the cover). These were from the club spares but did not fit at all well with the small ears not going round the pin etc I thought the new ones were going to help the gear change but actually made it a lot worse!! I finally sorted it all out by bending and generally reforming the springs till they fitted accurately and now the box behaves itself nicely, but if I had just put on the club springs and presumed them to be right my gearchange would still be very poor. Hope this helps!
The engine has been fully rebuilt, by me and I am no real expert, but with a variety of bits from unknown parentage. It is in a Featherbed frame so I don't think the E80 nuts are a real issue, but, the cover has been welded due to a past user kicking too hard on the 'ole starter lever, so maybe this has caused some distortion. That said there are no E80 nuts to adjust, so maybe G50 distorts when I lock up the footrest hangers... I managed to set up my Black Shadow engine gearchange with no probs and it worked in this frame, again no E80 nuts. I thought I was not getting enough lever travel to select top, as it goes in ok on the gear indicator and stays there, so I replaced the G61 with the old one without ears, still no good. Thanks for some good suggestions, it certainly gets you thinking writting all this stuff down.
Cheers
Cheers
I would say that is definite. If you don't have a battery tray, you need to put a spacer in to simulate an adjusted tray with threaded tube.
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A long time ago I helped with a bike with no battery carrier. Rather than having the long stud through the footrest carriers a suitable 1/2” bolt was used at both sides. No problems at all with the gear change. The down side is that if you drop the plot and slide down the road on the timing side you can bend the top of G50 and you don’t want to do that do you?