ET: Engine (Twin) Grosset Electric Starter Installation

[craig]

What to be careful not to do, for fear of shearing starter gear shear pin ?

I find the Rapide does not want to go backwards at a stop in first gear. Has not been an issue as I am paranoid about not being in neutral when stopped.
Have I read you can use this first gear as a hill hold when needed and not endanger the shearpin?
Would it depend on steepness of hill?
How the Rapide is loaded?

Currently I am frantic to find neutral when approaching a stop.
Any guidance please?

Craig

 

[Peter Holmes]

Craig, This was discussed on this forum quite recently, my experience is this, you are most unlikely to shear the starter pin just holding the bike stationary when on a gradient, used briefly it is quite a useful feature, I don't think the severity of the gradient or the weight of the bike will be a factor in shearing the pin, it is the explosive forces of a backfire that is the danger, and to be avoided at all costs, otherwise it could cost you a lot, the pin being the least of the potential problems.
The downside is if you come to a standstill on a steep gradient in neutral you will have to simultaneously push the bike forward a little whilst trying to select 1st at the same time, if you are not going to be stationary for too long it is advisable to come to a halt in 1st gear and keep the clutch disengaged, I don't like doing this, but it is preferable to crashing the gears trying to engage 1st gear, and then just when you think you have engaged 1st gear and are pulling away for a few yards it can pop back into neutral whilst you wait for the vehicle that is also pulling away behind you to smash into you, as I suggest, on a gradient leave it in gear, I don't particularly like doing this as I visualise what I am inflicting on the clutch lift mechanism in general, but it is the preferable option, if there is a weakness in the Grosset starter then this is it, otherwise it is great on a standard capacity, standard tune Vincent, in fact what it was designed for.

 

[timetraveller]

Some people find that using the needle roller thrust washer in the clutch lifting mechanism prevents that dificulty when changing gear or trying to find neutral. Do you have that fitted Peter?

 

[Bill Thomas]

I made a long gear indicator out of 1/4" , Sorry it was 1/2" !!!!!!!! sheet alloy'
I just move it by hand for neutral.

 

[Peter Holmes]

Some people find that using the needle roller thrust washer in the clutch lifting mechanism prevents that dificulty when changing gear or trying to find neutral. Do you have that fitted Peter?

Norman, Your needle roller thrust bearing is an excellent addition to the clutch lifting mechanism, and pretty much eliminates the pilot clutch plate drag that can cause difficult gear engagement, but the difficult gear engagement when trying to select 1st gear on a hillstart when a Grosset electric starter is fitted is not related to pilot clutch drag, and your clever device does not cure the problem, I can't really explain what causes the problem because I don't actually know, but when the sprag clutch in the starter mechanism is stopping the bike rolling backwards it is putting the gears within the gearbox under load, in effect locking them up, which in turn baulks gear selection. It all sounds rather dreadful, but you learn to live with it pretty quickly and get round the problem, I guess I have had mine fitted now for around 3 years and I can't now imagine life without it, neither could my right knee!

 

[greg brillus]

Just an update to how this bike is going.......So I received a new version of the starter ring gear from France.........Made just the same as previous versions, but of a softer material, so the teeth are not brittle........Gave this and the chain wheel to my machinist, he machined up a ring that pressed onto the new ring gear, and machined a small shoulder on the outer rear face of the chain wheel........This is to accurately align the ring gear to the chain wheel radially. We then spot faced all the 8 x countersunk holes in the ring gear, so it now takes normal allan head cap screws and not countersunk screws. The new screws are longer and pass through the wall of the chain wheel enough that some M6 nuts can be threaded onto these screws from behind.........All assembled up with loctite and the excess threads trimmed off. A test fit of the outer primary cover showed that the chain wheel could be moved in and out about 2 to 3 mm until the heads of the nuts hit the primary cover, so plenty of room, plus the extra security of the assembly not coming loose in service. The next culprit was (in my opinion a big cause of the starting issues) the ESA, This was "Beefed up" just using the simple method of replacing the inner small springs with lengths of 4 mm "O" ring thus adding a lot more compression to the cam assembly........So the ESA still works but it now deflects from one way to the other far less than before........time will tell on this one........Several tests cranking the engine with the cover off showed the ESA movement to be far less. Originally, the ESA would ramp up fully when the starter engages, then snap back the other way once the engine fired up........this was causing a huge shock through the primary back to the starter..........I also installed a new Deka battery, fully charged, and striped the 2 Mikuni's making sure the pilot jets were cleaned out.........These block up very easily if the bike is stood for some time with nil use........probably more common in hot climates where the fuel deteriorates rather quickly........I'll take the bike for a run in the next day or so, but it cranks over very well now with no adverse noises when the starter is used.........I also went to some trouble to cure oil leaks from the starter, this was back when I got the bike, before the ring gear teeth let go..........Hopefully all good now.

 

[greg brillus]

Sorry I think I posted this in the wrong thread, it should have been in the Godet starter issue posting........

 

[craig]

Grosset starter doing well, clutch cable and clutch needle lifter replacement has made neutral an easy find.
Sealed off kick starter shaft bore with cork, replaced main crank lip seal as well.
Revised breather timing from 75ATDC/30ABDC to later at 110ATDC/65ABDC.
Great riding weather today.

 

[van Ginneke]

Hi, I have a question about the fitting of the Grosset G50 plate.
See picture.
Is it vital to have the Grosset G50 plate 'captured' by the kickstart bush ?
Or can I take out the recess and fit a separate fill-up ring under the rim of the bush?
a.t.m. the bush does not fit anyway as the holes in the Grosset plate / case do not line up.
Advice please! Thanks.

 

[greg brillus]

The kick start bush really acts as a datum for the alignment of the plate.......Ideally you should use the bush, and trim slightly any material from whatever stud holes that don't quite line up. It is very important that these studs do not get moved inwards as the plate is pushed home, especially any of the lower ones that could start an annoying oil leak from oil passing along the studs via the primary housing if any of these got disturbed. Also another tip is to remove a small amount of alloy on the inner top edge of the plate immediately aft of the valve lifter cable abutment assembly........this will make any further maintenance of the cable/ lifter rod much easier. Be sure the battery tray E80 nuts are clear of the plate when you do up the attaching studs/nuts, then readjust these after the assembly is all bolted fully home........It is important that the G50 plate does not bend from being hung up, as this will upset the gearshift, generally making the action of the gear lever stiff to move. Good luck with it all........