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Cota 172 Restoration

Posted: Mon Jan 25, 2016 8:37 am
by Phil 850
Hi all
I have just bought a Montesa Cota 172 to restore as a casual ride bike and possibly some trials days.
The bike is currently blue.
What is the correct colour for the frame and tank.
Is there a spray can that matches the correct colour for the tank ?

Regards
Phil

Re: Cota 172 Restoration

Posted: Mon Feb 08, 2016 9:41 pm
by Phil 850
Just trying to start my :montesa 172.
It has a nice blue spark at the plug, but how do I set the carby for starting.
I can't find a Choke on the Amal 620/406 that is on it ?
Any hints would be appreciated.
Phil

Re: Cota 172 Restoration

Posted: Mon Feb 08, 2016 10:25 pm
by David Lahey
I think that carby has a "tickler" which is a button that you press downwards until petrol squirts out a little hole under the button. The button holds the floats down which allows the fuel level in the bowl to go way above where it is for normal running. Don't hold the tickler down for too long or you will put too much petrol in the crankcase
On some bikes you have to tickle it a bit even after the motor starts, to keep it running until it gets a bit of warmth in the engine

Re: Cota 172 Restoration

Posted: Tue Feb 09, 2016 8:38 am
by OKOAustralia
Phil
We have inexpensive replacement round and flatslide carburettors that would improve the throttle response and overall rideability of the Mont..
Regards
Denis Lovett
07.3040.0231
www.oko-australia.com.au

Re: Cota 172 Restoration

Posted: Tue Feb 09, 2016 9:34 pm
by Phil 850
Thanks David
I used the "tickler", but to no avail.
Pulled the plug and it was dry but still had spark.
Tickled some more and had a sort of "kick back" but didn't actually fire.
Pulled the plug again and it was wet, so now at least it's getting fuel.
Tested the plug again and now there is no spark :(
It is a KLG FE80, possibly original so I will by a new plug or two (NGK B7ES & a B6ES) and see how one go them goes.
The plug lead is a bit fried, is there some way I can test it and the coil :?

Phil

Re: Cota 172 Restoration

Posted: Tue Feb 09, 2016 10:07 pm
by David Lahey
Weak spark could be caused by many things.
Look for (in order of probability of being the cause):
sparkplug carbon fouled
points dirty/stuck open
condenser failed
broken/corroded LT wiring at the stator
poor earth for motor or HT coil
points wire shorting to earth somewhere (includes inside the killswitch)
loose connection in LT wiring
points set wrongly
loose stator coil screws
loose stator plate screws
failed stator coil winding
failed HT winding of HT coil
failed LT winding of HT coil
broken HT lead/plug cap
loose flywheel
sheared flywheel key
main bearings have so much play that points are not being opened
rust causing flywheel to touch stator

The coils can be tested using a multimeter to measure the resistance of the windings

Re: Cota 172 Restoration

Posted: Wed Feb 10, 2016 8:08 pm
by Phil 850
Thanks David
Fitted a new plug, tickled the carb, couple of kicks aaaaaannnnndddddd........ Vroooom :D

Re: Cota 172 Restoration

Posted: Sun Feb 14, 2016 4:31 pm
by Phil 850
I was looking at the forks and noticed that if I hold the front brake and rock the bike back and forth there is clearance and movement at the top of the lower fork leg.
I presume that the bush is worn and needs replacing.
Does anyone have a manual that describes what I need to do.
Where can I get the parts I need also.
Image

Regards
Phil

Re: Cota 172 Restoration

Posted: Sun Jun 26, 2016 3:52 pm
by Phil 850
I have an issue with my kick starter (well actually 2 issues).
The pin that goes through the lever has a groove in it and I presume there should be a detent ball in the lever.
Does anyone know how to fix this ?
Image

Also the kickstart shaft looks bent and damaged from the loose lever.
Is this a big job to replace and where are parts available from.
Image

Re: Cota 172 Restoration

Posted: Sun Jun 26, 2016 6:54 pm
by David Lahey
I haven't worked on 123 forks, but 1970s forks don't usually have a replaceable bush. If the fork slider bearing surfaces are worn that much you could spend a lot of money having bushes fitted, or find some 123 sliders that are not worn out, or for the most economical option, fit some similar forks from a different (common) bike.
A possible reason for why the sliders are worn is what appears to be poor condition of the surface of the tubes
If they are 30mm diameter fork tubes, TY175 fork tubes should fit into the triple clamps