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Intermediate timing gear, dynamo Dommie 99

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Intermediate timing gear, dynamo Dommie 99

Posted by steve_coleman at March 08. 2017

I have a 57 dominator 99 which may have the wrong intermediate timing gear/sprocket fitted, can someone kindly give me some guidance . In the WC Haycraft book on dominators in suggests two methods of fitting timing sprockets and chains, one for 55-57 dynamo models and one for 58-65 model. the first states that when the teeth on the half-time pinion and intermediate gears are aligned the marked tooth will be at the top. On the second instruction (58-65) states in this position the marked tooth will be at 11 o'clock. This suggests the intermediate gear is marked one tooth differently for dynamo models, can anyone tell me if this is the case? do I have the wrong gear fitted?

Many thanks,   Steve Coleman

Re: Intermediate timing gear, dynamo Dommie 99

Posted by anna jeannette Dixon at March 08. 2017

Hello  THIS is Stright Forward   Right let start with the crankshaft timing gear with the worm removed you will then see a punch mark in-between the teeth on this gear.  this pinch mark need to be at top dead centre from the drive side cylinder or left-hand side and the left-hand side valves must be closed are you following me!   Next up you must fit  the chain  and intermediate gear  do not forget the thrust washer  for the intermediate gear and the camshaft  gear together in one go over the keyway for the camshaft and have the intermediate gear punch mark  looking downward to match up with the crankshaft timing gear punch make they should be opposite each other  and  punch marks on the intermediate gear  where the chain is  and the punch mark on the camshaft sprocket  should be at 11 o'clock  and all this should be fitted in one go all together to ensure you have the right valve timing  and ignition timing  with this all in place you can then do you ignition timing and on a modle 99 it will be 32degees before top dead center static timing   and always time your engine from the drive side  or left-hand side has this is cylinder number one,. on a magneto or distributor  the number one lead in the one nearest  to the battery box      now read careful   and have fun  with it ,   yours anna j  

Re: Intermediate timing gear, dynamo Dommie 99

Posted by anna jeannette Dixon at March 08. 2017

Hello please make a note a single cylinder engine  only fire's once every 720 degrees or two turns of the crankshaft, Now a twin cylinder engine  fires twice  in every  720 degrees or once in every  360 degrees   have you all now got it in your heads     well have fun with all this   yours anna j 

Re: Intermediate timing gear, dynamo Dommie 99

Posted by steve_coleman at March 08. 2017

Previously anna jeannette Dixon wrote:

Hello  THIS is Stright Forward   Right let start with the crankshaft timing gear with the worm removed you will then see a punch mark in-between the teeth on this gear.  this pinch mark need to be at top dead centre from the drive side cylinder or left-hand side and the left-hand side valves must be closed are you following me!   Next up you must fit  the chain  and intermediate gear  do not forget the thrust washer  for the intermediate gear and the camshaft  gear together in one go over the keyway for the camshaft and have the intermediate gear punch mark  looking downward to match up with the crankshaft timing gear punch make they should be opposite each other  and  punch marks on the intermediate gear  where the chain is  and the punch mark on the camshaft sprocket  should be at 11 o'clock  and all this should be fitted in one go all together to ensure you have the right valve timing  and ignition timing  with this all in place you can then do you ignition timing and on a modle 99 it will be 32degees before top dead center static timing   and always time your engine from the drive side  or left-hand side has this is cylinder number one,. on a magneto or distributor  the number one lead in the one nearest  to the battery box      now read careful   and have fun  with it ,   yours anna j

Many thanks for your prompt reply Anna, I am ok  with the assembly process which is currently just as you suggest, my worry is that both the original 57 manual and the Haycraft manual suggest the intermediate gear is different for the pre 58 dynamo bike and when the crank pinion and intermediate gear aligns the sprockets should present at 12,clock and not 11,o'clock. this would suggest that the dynamo models require a different intermediate gear to later bikes, to add to my confusion the club spares list an intermediate gear for dynamo engines.

Are you saying this gear is the same for all models, and I am ok with my 11,o'clock set up?

Thanks again Anna. Steve

Re: Intermediate timing gear, dynamo Dommie 99

Posted by philip_chester at March 08. 2017

Steve,

The following is taken from Norton by P.L. Garratt.

Fitting timing sprockets and chains. 1949-57 Dominator 7,77,88,99.

Fit half time pinion with the chamfered edge outside and tap home with tubular drift. Fit thin washer to camshaft, followed by spider clutch spring and fit camshaft key. Replace thin washer [ this is thinner than camshaft washer ] to intermediate gear spindle and rotate engine until the marked tooth on the half time pinion is in the TDC position. Rotate camshaft until the keyway is also in the TDC position. Before fitting the chains to the sprockets, mark the tooth on either side of the marked space on the intermediate gear wheel, because when the chains are in position the timing mark is obscured. Place the magneto chain [ the narrower of the two ] on the inner of the two sprockets on the intermediate gear and the camshaft chain on the other sprocket. Rotate the intermediate gear until the marked tooth is in the BDC  position. The chains and sprocket assemblies may now be placed loosely in position, the magneto sprocket and ATD mechanism meshed with its driving chain and the whole assembly pushed home checking that the clutch spider spring is located with one leg either side of the friction plate peg. When the half time pinion and intermediate gear are in mesh, the sprockets should be in the eleven o clock position. The valve timing is correct when six outer plates on the camshaft chain separate the marked teeth on the sprockets with the half time pinion and intermediate gear correctly meshed.  FOOTNOTE. I have read through the fitting procedure for 1958 on and apart from the distributor as opposed to a magneto the end process is the same ie all pinions in mesh, sprockets at 11 o clock and six outer plates separating marked teeth.  Hope this helps, Phil.

Re: Intermediate timing gear, dynamo Dommie 99

Posted by steve_coleman at March 08. 2017

Previously philip_chester wrote:

Steve,

The following is taken from Norton by P.L. Garratt.

Fitting timing sprockets and chains. 1949-57 Dominator 7,77,88,99.

Fit half time pinion with the chamfered edge outside and tap home with tubular drift. Fit thin washer to camshaft, followed by spider clutch spring and fit camshaft key. Replace thin washer [ this is thinner than camshaft washer ] to intermediate gear spindle and rotate engine until the marked tooth on the half time pinion is in the TDC position. Rotate camshaft until the keyway is also in the TDC position. Before fitting the chains to the sprockets, mark the tooth on either side of the marked space on the intermediate gear wheel, because when the chains are in position the timing mark is obscured. Place the magneto chain [ the narrower of the two ] on the inner of the two sprockets on the intermediate gear and the camshaft chain on the other sprocket. Rotate the intermediate gear until the marked tooth is in the BDC  position. The chains and sprocket assemblies may now be placed loosely in position, the magneto sprocket and ATD mechanism meshed with its driving chain and the whole assembly pushed home checking that the clutch spider spring is located with one leg either side of the friction plate peg. When the half time pinion and intermediate gear are in mesh, the sprockets should be in the eleven o clock position. The valve timing is correct when six outer plates on the camshaft chain separate the marked teeth on the sprockets with the half time pinion and intermediate gear correctly meshed.  FOOTNOTE. I have read through the fitting procedure for 1958 on and apart from the distributor as opposed to a magneto the end process is the same ie all pinions in mesh, sprockets at 11 o clock and six outer plates separating marked teeth.  Hope this helps, Phil.

Thanks so much Phil, it seems I am ok with my present set up after all.

I am very grateful to you for taking the time and trouble to get this info to me, I have been looking for some time for a copy of P.L. Garrett,s book as yet with no success, I will continue to look.

Best regards, Steve.

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