Hi,

Fiddling with a Montesa Cota123, around early 80's white tank model, Engine number starts with 28M

Encountering difficulty gaining information as below, hoping people here can help, in particular I have been told in the Australian trials forums that King Scorpion is the Montesa Man!

Engine oil capacity, have two different numbers given, 600ml or 900ml.

Have managed to confirm that best fuel to oil ratio is between 4-5% 40/50:1

Also trying to locate a new air filter, round internal cage type

And would like to know more about changing from Amal carb to a Mikuni.

Type, still waitin price from inmotion

BR

Geoff Kinsela

Hi Geoff,

 

I have enclosed the owners manual for the 123 (28m) if it helps, as regards the air filter, it seems that the 200 Cota maybe the same, as the two share many similar parts as I have found when restoring my 81 200. Please see links below for sources of parts mainly in Europe, Jared Bates @ Southwest Montesa in the USA is good also. Hope it helps! Mark Trueman

 

 

Clasicas Vallmoto | Todo para su Montesa Clasica

 

MONTESA - Clasicas Auradell

 

RECAMBIOS PARA MONTESA | Motos J. Alonso

 

http://trickytrials.thetao.co.uk/

 

https://www.inmotiontrials.com/

 

http://www.southwestmontesa.com/

 

 

 

 

 

 

 

 

Hi again,

Thanks for all the information, still trying to get to the bottom of this oil quantity issue.

Am I correct in thinking that there are two different scenarios for these Cota's, as in for the older models there were two seperate fill points and in latter models a combined fill point. I can only find one fill point in mine as in the pic attached.

My bike is white tank Cota123 almost identical to Cota200 I am being told I will include some pics in next post. Someone mentioned somewhere that the bottom ends are identical just the top ends are different.

I am assuming that 600ml is for older models with seperate fill points, and 900ml is for the models with combined.

Looking forward to any comments

As promised

Hi, the gearbox is the same as the 200 Cota, so the quantity is 900ml (See attached last page of manual) Cheers, Mark

Link to an Air Filter, same as the 200 also.

 

http://www.francetrialclassic.com/en/oil-air-filters-spark-plugs/4309-montesa-cota-123-200mh-242-air-filter-moss.html

I'll throw this in here rather than start a new thread - At the risk of sounding daft I'll dive in,

 

I know this fuel mix topic has been done over and over, but I can't see any consistency. Differs between models let alone a 1974 & 2005 one.. as far as I can tell, but I'm reasonably new to two strokes.

 

Fuel/oil mixture for the 172 cota is recommended to be 5% SAE which is 20:1...

 

My question is:

Now that we don't put those single grade oils in, and that seems really lean for what oils and fuel we use now - what is the equivalent with a full and/or semi synth? Was going to experiment with 30:1 (or 3.33%) full synth.

 

Not too keen on buying 40 SAE and sticking that in as a 5% mix.. Doesnt seem right somehow, especially now with the different fuels. 

 

The above OP's mixture seems incorrect by my questionable math skills..

5% is 20:1 and

4% is 25:1, so

3.33% is 30:1 and 

2% is 50:1  

 

 

Forget the 5%. A good synthethic oil should be mixed at 1.5-2% as a maximum, unless you want to keep your back foggy.

 

Your motorbike has a "small engine" and that means only one kind of oil (SAE 10W30 like Motul Transoil), and 750 (when refilling) to 900 (for a brand new engine) cc.

Cheers, good to know. Think I'll play around a bit and keep looking at the plug. 

 

Engine oil - Yep, thats the sort of thing I've got in it, works well.