850 E/S Commando

Hi Steve,

Not quite sure what you mean by cranking speed. My starter turns the engine quite slowly but normaly it only needs to go over compression once and it bursts into life. The same with the kickstart, one gentle prod with the ignition off then ignition on an a firm kick and it will start.

I have Pazon ignition and a single MkII Amal. What is your setup?

Regards

Tony

Hi Steve,

As Tony rightly points out, your Commando shouldnât take that much starting. I too have an electric start model, as well as a kick start only model, both are running Boyer ignition & SU carbs, & both will start easily with one or two kicks & I have a quite badly injured back, so am not as good at that sort of thing as I once was. The E/S will crank over two or three compressions & start readily also. If you are having to kick 20 or 30 times, there must be something wrong. If your sprag has gone over centre, thereâs a good chance the crankshaft sprocket & starter gear have worn where the sprag runs on them, so these should be carefully inspected & if in any doubt, replaced along with the sprag or the same will happen again.

Regards, Tim

I'm afraid the sprag, sprocket and starter gear are wear items and will eventually have to be replaced together. With one of the new starter motors, heavy leads and 300 cranking amp battery, I have no trouble in starting after a couple of bursts - even in the depths of winter. Using Wassell electronic ignition but I had to change its black box recently after 10k miles - I do carry a spare. The Trispark I had failed after 2k miles a couple of years ago - they replaced it directly from Australia at the time, but you tend not to carry a spare at £210 each.

Steve, you still shouldnât have that much trouble starting the bike, even after it standing idle for a while. Iâm suspecting it may be wet sumping, making it difficult to kick over & that the fuel in the float bowl is losing itâs volatility. If Iâm going to be leaving a bike to stand for a while, I try to leave the tank as full as poss & empty the float bowl either by using any drain screw, which the Mikuni has, or running out of fuel with the taps off. This way, when you come to start it again, you should get good fuel in the carb to start with. Itâs also worth draining the sump & putting the oil back in the tank, this makes it a lot easier to kick over & precludes the risk of blowing out the crank seal.

RE your question as to roller speeds, itâs not that critical to achieve a specific speed, but using the two examples you give, if Iâm reading correctly you are either able to turn the WHEEL at 79 rpm or 252rpm. Assuming a 19 inch rear wheel, you should have roughly 81â circumference so 79 rpm equates to approx 6mph & 252rpm would equate to around 19mph. If you were push starting, 6mph would be a realistically achievable pushing speed & youâd probably use second or third gear, so thatâs the option Iâd try first. If you went for the other option, you may find it too much load for the motor & you would probably have to use top gear to prevent the engine spinning too quickly, however, it would probably still work ok like this. At the end of the day, you have two roller speed options & four gearbox options, giving you eight possibilities, with a bit of experimentation, you should be able to find something that works.

Regards, Tim