HELP mag sprocket slipping

[jonathanjoy]

Hi
The mag sprocket is slipping on my flyer. The sprocket has no slot for a woodruff key but the Lucas MD2 has. Is this usual ?. If so is it just a case of applying a fair amount of torque to lock it. NB any misfire tends to loosen it. Any tips ?

[dave bushell]

It should be a good taper fit only, plus nut and washer of course!
Dave

[BRIAN MARSHALL]

If you lightly tap the sprocket onto its taper, without the nut and washer, it should ‘pick up’ onto the taper, and be difficult to remove without a puller or a tap from the other side. If it won’t do that there is probably some damage to the taper on the mag or in the sprocket. If the sprocket is slipping there is very probably some damage to one of the tapers. If only slight you may be able to cure it by lapping the two items together with some fine grinding paste, but don’t overdo it, and do very carefully remove all traces of grinding paste before retesting the fit. Also make sure that there is no oil or grease on the tapers.
Brian

[jonathanjoy]

Thanks for the replies, tightened it up , I think its OK.
Can’t work out why its difficult to start, seems to like fully retarded now. Starting should be fully advanced ? (32 degrees BTDC) ? throttle just open ?, small slide (Binks) is this the choke ? partially open
Anybody else has problems starting, using 3 jet Binks, what settings do you use. 😥

[Richard Moss]

I realise that this thread is veering away from your mag sprocket but I’ll throw a couple of things your way. It seems that you’re slightly unsure of whether the issue is in fact carb related. Is that right?

Carburation-wise, if you think that you are flooding upon start up due to incorrect float height then just tickle and turn the fuel off to start. We’ve done this for years on our bikes, mainly if a float needle sticks open, as they do quite often. Better to get someone to give you a push (to get the engine speed higher) and start with the throttle full open just to clear it out and give it some air. If the float height is too low then I guess you’ll see no evidence of fuel in the carb when you are tickling it. If you suspect this, then use easy start. If it doesn’t fire on easy start (and you’ve isolated flooding) then it’s a fair bet under normal circumstances that it’s ignition related.

I don’t think I’ve ever really had any massive problems with float height. I think that maybe mixture is more critical at the rotational speeds and duration of rotation available with a kickstart starting procedure. Since we don’t use kickstarts and either use starting rollers or more usually push start, you’ve got more of a chance to overcome slightly imperfect conditions. Employ the services of a energetic youth and see if it starts then…

[jonathanjoy]

Yep not to sure if its carb or ignition. When it does start, it bursts into life, but if I then try to get it to idle it will fade and stop. One thing i have done is put a small amount of two stroke in with the petrol. Will this have an adverse effect on the idle ? ( I assume its the smallest jet).

Kept up the revs today and rode it down the road in first. What I buzz, they really pull in first, WICKED…… still smiling. I can see why you guys love them.

Lots of people stopped, and wanted to know about the bike. Can’t wait to take it out for a ride , but I need to sort the running out first,

Does easy start have any detrimental affect on the engine ? I’ve heard that engines get “addicted” can’t see why.
How critical is the position of the advance lever on starting ?

[Author]

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