Hard kicking Cub

[fasteddie]

I am new to vintage bike resto. but have run into a problem with my 66 Cub.  It is nearly impossible to start by kicking with the lever.  Even bump starting is difficult as the rear tire lock up when the clutch is released.  Once turning over it starts right up and runs well.  I have removed the top end and am going to replace the high comp piston with a stock 7-1.  Before I reassemble I believe somting else must be wrong as the Hi comp piston cannot cause the bike to kick over with that much required force.  I have owned many bikes but never run into this problem before esp on a small single.  Any help or ideas?  Thanks

[R]

If the back tyre locks up when you bump start it, are you coming down on the seat just as you let the clutch out - they don't call it 'bump' starting for nothing.
Also, are you using 1st gear or a higher gear - 2nd or 3rd is usually required.
Pull the clutch in as soon as the engine fires.

If you take the spark plug out, does the engine turn over easily for lots of revs when you operate the kickstart ?

Sounds like your ignition may not be up to snuff - try reducing the spark plug gap to 2/3 of what it should be, and see if that makes any difference. Don't leave it like that, whether it does or not, it just tells if your ignition is weak.

Engines that start easily feel easy to kick over.
You just need to sort out why...
Is your spark timing and cam timing absolutely correct,  ?

Hopethishelps.

[fasteddie]

I use 2ed gear when bump starting and jump with force when the clutch is released.  This will work if the engin turns over and it will fire up right away.  But using the kick starter is almost imposible to get the bike to turn over.  I have had a BSA Goldstar 500 and this feels like trying to start the 500 without a compression release.  I can come down on the lever with all my force (170 lbs and 6 ft) and the lever will not budge.  I am thinking that somthing is dragging.  I have discovered the bike has a Wassell high output magneto.  The bike is a Mtn cub and has no battery.  Could this be the problem?  Thanks karma for your help.

[rogerwilko]

Yes, those Wassell magneto's certainly increase the compression!

[fasteddie]

Thanks Roger.  I assume the very strong magnets held in the Wassell Magneto contribute to the hard kicking?  There are no drag marks on the mag itself so I surmise the only other infulence the mag might have on starting would be the strength of the magnets themselves.  It would seem then that the benefits of the added spark strength are offset by the hard starting.  That is a dilema.  Thanks again.

[Bomber]

Magneto increasing compression... thats a new un on me.... It's not the first of April is it?

[R]

If you take the spark plug out, does the engine turn over easily for lots of revs when you operate the kickstart ?

[R]

P.S. Some trials bikes have a compression release fitted (of the 2 stroke variety) that threads into the head somewhat like a spark plug. This doesn't have one of these, does it ?

[Rex]

Dunno what a Wassel trials mag would be on a Cub, as they never were mag-equipped bikes. Some variation on the  ET ignition I assume, but no matter what it is, it isn't causing your problem.
As someone else has said, what happens when you kick it with the plug out? Does it spin freely, or still stiff to rotate? Are you sure the kick mechanism isn't catching somewhere internally and mechanically locking it, ie does it slowly descend with your weight on it (and plug in, obviously)?

[wetdog]

sounds like kick start rachet mechanisum jaming with quadrant to me

[fasteddie]

The bike is a US Mtn Cub which traditionally came equiped w/o battery and were mag. ignited.  However the stock mag supposedly had two keyway postions to account for the high and low compression pistons.  The Wassell has only one so after the new 7-1 comp piston is installed I will have to advance the timing some.  I really don't understand how the mag would affect the compression other than if it were dragging on the stator.  I will try your kick starter suggestions and try the kick effort when reassembled.  I thank you all for the time to help me with my problem.

[wetdog]

is this the four cycle motor fitted with ET ign via the alternator and not a two cycle fly wheel mag ?

[rogerwilko]

Der.... I was being sarcastic!

[Bomber]

I'll let you off then.....

[fasteddie]

The mag is a aftermarket stronger than the original.  The Mtn cub came std with mag ignition and not the traditional battery supposedly to make the bike competiotion ready easier than the battery style ignition.  I am sure the outfit was not canabilied from a 2 stroker.