starter ring on 950

[boydogs]

Today tried to fit a new starter ring to flywheel, I did as the forum recomended by leaving flywheel in freezer over night, Then put starter ring in the oven on max heat, which was 250 degrees C. for two hours. No where near fitting. So any more suggestions, ie. Blacksmiths forge, Barbeque,Large press, garage. All ideas welcome. boydogs. The new ring is the identicle size to the old one.

[bmcecosse]

Oh dear - most report that amount of heat works well..... Stick with heat rather than press - you just need MORE!

[DAVIDMCCULLOUGH]

When I fitted the new ring to my sidevalve we heated it up with oxy accetelyne until red and then fitted it, it cools almost immediately so you dont have much time for adjustment.

[SUE482]

This is how I did it.
[frame][/frame]
If the oven isn't hot enough heat it up on a boiling ring or in a BBQ oven. I brought the flywheel direct from the freezer to the cooker placed on a heat resistant pad took the ring from the heat source and it should slip on easily if its hot enough, if it doesn't its not hot enough. Make sure you put it on the right way round.

[boydogs]

Thanks for the tips, i am going to try this time with two good blow lamps after oven. I will let you know how i get on . Thanks again boydogs.

[Tom and Maria]

I'll be doing the same job this weekend, what way round is the right way round? Sharp ends of the teeth towards the gearbox?

Tom

[bmcecosse]

Indeed - the inerta starter enters from behind......

[boydogs]

If you look on the ring the inside edge is bevelled slightly, only on one side this bevel fits over the flywheel, or the markings on one side of the ring faces the flywheel so you can`t see markings when fitted. Mine isn`t on yet had two attempts, My next options are Throwing onto a large fire, or a Blacksmiths Forge. If ring gets to hot ie. red will it not loose its temper ? No jokes thanks. boydogs

[bmcecosse]

Yes - it will.

[Ufudu]

Just received my gear ring from BM yesterday. Lining it up with the existing ring/flywheel at first glance it seems like the new ring is not quite circular but it may be the bad light in the garage. Seems out by a fraction of a mm in one area, enough to see with the naked eye anyway. Anyone else experienced this? Non-circular gear rings would certainly make the fitment a lot more difficult I'll have another look tomorrow in better conditions.

[Ufudu]

I seem to recall the manual says heat the ring to 350C, does anyone recall if this is correct? At a 13 m/m K thermal coefficient of expansion this translates to just under 1mm on the diameter of the ring if my calcs are correct after a glass of wine

[Trickydicky]

Just received my gear ring from BM yesterday. Lining it up with the existing ring/flywheel at first glance it seems like the new ring is not quite circular but it may be the bad light in the garage. Seems out by a fraction of a mm in one area, enough to see with the naked eye anyway. Anyone else experienced this? Non-circular gear rings would certainly make the fitment a lot more difficult I'll have another look tomorrow in better conditions.

A lot depends on how they hold the unmachined ring when they cut the gear, if they clamp it on a mandrel to cut the gear it could "spring" when it is removed. Also you don't know how it has been handled since it was manufactured, it could have been dropped

[Tom and Maria]

Mine was also slightly out of round, but nothing an acetelyne touch couldn't handle, no colour in the ring when it fitted, so maybe possible with a good blow torch after being in the oven?

[boydogs]

Sent email to Rob Thomasson MMOC Technical adviser, He said there are a batch of duff starter rings out there with the inside diameter if the ring slightly bigger than it should be, i am trying to get exact measurements to send him. To me the ring is just less than 1mm larger than the old ring, this must be why it is so difficult.I will let you know how i get on. boydogs

[bmcecosse]

Obviously your's is not 'bigger' - or it would fall on!

[boydogs]

Not had reply from Rob, So i asked around at a classic bike meeting, I was told that the steel on the inner part of the ring would be easy to File with a half round file, Take the 1mm off and try again with oven/freezer. I did this very carefully and squarly i had to file twice around ,measuring with the old ring, took about 20 mins, got them both exact then used oven system, ring started to go on and i used a copper hammer to tap it on, good job. The steel was easy to file.Thanks for all the advice received, boydogs

[bmcecosse]

Well done !