Its nothing to do with the ignition Howard. It is 'well known' that the one problem with these starters is the mechanical problems which occur if the bike is allowed to roll backwards whilst in gear. It does not matter whether the engine is running or not. If the bike is in gear, with or without the clutch held in, then if the sprag clutch tries to rotate backwards that damages things. The bike MUST be taken out of gear if there is any chance of it rolling backwards. I met one chap at a French rally who had stopped his bike in the customs hall at Dover, stopped the engine and then let out the clutch. The bike leaped forwards several feet and hit the customs counter!! The stored energy could only have been in the sprag clutch which must have been on the verge of self destruction. There are many people who are happy users of this starter kit and it is now a well developed item but if there is a new system which will embody a bendix or pre-engagement device then it would be a much superior item.
Electric start wanted
- Thread starter Howard
- Start date
Strange thing to happen....as the spragg assembly only rotates when the starter is engaged...interesting..The only system i've seen using the other set up you mentioned, and this using a conventional car type starter and a small ring gear mounted on the chain wheel was the type used on the RTV engines here in Australia. Built by Terry Prince and Rodney Brown back in the 90's.....the starter mounted low and under the left hand side inboard of the primary. Originally designed to run a belt primary, which sadly was omitted in favour of a conventional chain, with the resulting oil bath causing oil ingress to the starter....not an ideal situation as some owners have learnt.....About 18 months ago i rebuilt one of these engines and converted the primary to a belt drive.....end of starter/ oiling problems and a much better set up now.......GB.
HI ,
If during maintenance you require to turn the engine over in reverse(backwards) you must remove the starter motor( three screws hold it on). I(f you dont it will cause the sprag clutch to lock up, with risk of damaging the sprag clutch. An example would be removing the engine shock abosorber nut.
If during maintenance you require to turn the engine over in reverse(backwards) you must remove the starter motor( three screws hold it on). I(f you dont it will cause the sprag clutch to lock up, with risk of damaging the sprag clutch. An example would be removing the engine shock abosorber nut.
Hi Norman, My concern is not to change too much on the engine castings, and a bendix arrangement (if one was available) takes up a lot of space. I'm not a sprag clutch fan either, but I think it's the lesser of the evils. I'll take the warnings on board and let you know when I get it wrong, as I surely will.
I think your friend's problem was due to something other than stored energy in the sprag, there just isn't anywhere to store enough energy to launch bike and rider several feet. It sounds to me like the starter motor was running.
H
That was my plan as well, use the decompressor to ease the load on the starter. Afterall, a giant Caterpillar engine can be started with a relatively small starter motor just by using a decompressor. It was pointed out to me recently that the decompressor linkage on the Vincent is only designed for easing the engine over compression with the kickstarter. If you subject it to impact hammer type loads at starter rpm of maybe 3-400 rpm then additional loads at idle speed for shut down, the decompressor linkage will take a beating it is not designed for. The parts look like a hummingbird's skeleton.
So one really needs a starter that is up to the job of rotating the engine without use of the decompressor. Now the decompressor parts might last quite awhile before letting go, and if it the bike is not in daily use could last quite some time, but the point about the relative fragility of those parts made sense to me. If a part in the Decompressor linkage breaks at starting or idling rpm, the potential for major damage in the timing chest is great. I would rather take a chance on having to replace the starter shear pin now and then, or even the sprag.
So I'm stuck waiting for Paul Hamon, or doing like Howard suggests, trying to develop my own setup.
Glen
So one really needs a starter that is up to the job of rotating the engine without use of the decompressor. Now the decompressor parts might last quite awhile before letting go, and if it the bike is not in daily use could last quite some time, but the point about the relative fragility of those parts made sense to me. If a part in the Decompressor linkage breaks at starting or idling rpm, the potential for major damage in the timing chest is great. I would rather take a chance on having to replace the starter shear pin now and then, or even the sprag.
So I'm stuck waiting for Paul Hamon, or doing like Howard suggests, trying to develop my own setup.
Glen
Last edited:
Two bikes , my egli 9k miles since 2008 and my shadow 16k since 2009 both have Grosset starter systems with no sprag clutch issues. There are no crankcase mods but the outer cover has to be machined internally for clearance and a slot cut in the bottom, the kickstart quadrant has to be slimmed down also. In all this time I've broken two shear pins and had two lots of brushes. Not a bad trade off for the joy of pressing the button, especially if you stall in traffic or have a titanium knee! I would hate to be without my starters now. One observation is that the one on the egli has an easier life and I'm pretty sure that is because the egli has mikunis which make the bike idle better and stay in tune at all times. Basically the system starts the bike on idle so the idling is crucial to quick starting.
mark
mark
Hi Glen, I use the Enfield type decompressors not the Vin valve lifter, so I'm not expecting the problems you describe........... just an oily head!
You should be the ideal person to build an alternative starter, judging by your Egli ....... and judging by how long that took, if you finish by the weekend, I'll order the second one from you.
H
H
You should be the ideal person to build an alternative starter, judging by your Egli ....... and judging by how long that took, if you finish by the weekend, I'll order the second one from you.
H
H
The only way that could happen, is by pressing the start button, with the engine in gear. Which means, as Howard says, the starter motor is turning.
Howard, the plughole type decompressor is ideal, except in my case Terry tells me that both plugs and a hot ignition are needed to get the most from the head.
Did you notice any difference in performance when switching from two plugs to a single plug plus decompressor?
Glen
Hi Glen, I've never had twin plugs mine is just a cooking Rapide engine (ish). Rumour had it a batch were made with the plug holes on the wrong side, so the works just redrilled the right side as well. When I bought the Egli from Slater's it had blanking plugs in the second hole, and it used the standard valve lifter. The valve lifter fell apart expensively in the timing chest, so I switched to decompressors for safety as much as anything.
H