I'm back after a long hiatus just couldn't keep away from the throttle, my last bike was a 2002 Sherco 2.9

I had an opportunity to purchase a Montesa Cota 247 COMPLETELY rebuilt New everything. New main bearings, rebored, new piston, new rings, chains,  It has only been run for about 30 minutes after the rebuild.

The owner is unsure of the year at this point it has been sitting a good number of years, my main question is about the break in period I have no idea on this bike

Also any help of mixing ratio's , Crankcase oil, or other valuable information would be greatly appreciated

I should have it in a couple weeks and I'll look for numbers on the frame

Thanks

Chuck

Take it easy in terms of long downhill runs for a few hours...but apart from that standard trials type riding is pretty ideal for engine break in ...but avoid labouring the engine ie: pulling away in a gear that is too high.
I would also suggest that you get an after-market compression release - as the starter gear is very vulnerable and difficult to obtain.  I run 25:1 and castrol VMX80 in the gear box.  Some guys recommend ATF but my 76 model jumps out of gear in every gear and false neutrals everywhere.  With VMX it only jumps out for first, occasionally 2nd  but no false neutrals.  I am guessing that yours is around a 75 model - engine number should tell you.

Thanks for the insight and the heads up about the compression release

 

I notice there are 2 filler caps on the left side of the engine?
Clutch & gearbox?

1 hour ago, dirtrider6 said:

I notice there are 2 filler caps on the left side of the engine?
Clutch & gearbox?

Yes, outer one is clutch, lots of people suggest ATF in there, second one is gearbox, originally supposed to be SAE-80 gear oil in there, but modern multigrade is used by some. I don't have capacity to hand, but you need to fully drain what's in there, then add the correct amount as there's no recognised way to check the levels. Also I believe your bike is pre-'75 as it has the under clutch arrangement. I'm told '74 was the biggest selling model. Frame number is stamped into the left side of the head-stock and engine number is stamped into the top of the front engine mounting lug of the crankcase. Usually engine and frame numbers match from the factory and will start 21M????

I should be picking it up early next week, I'll have to check the numbers and get new fluids in it

Hopefully I can find out the capacities 

Had to go to shop, but capacities I have are - clutch = 200 cc 10/20w or ATF, gearbox = 300cc 10/40w or 75w (should be a GL4 oil due to brass/bronze parts in there), forks = 190ml 10, 20, or ATF (use different weight oil to suit rider, but action should be "soft" compared to dirt bike), original mix is 25:1 with engine oil, but modern synthetics can run up to 50:1 - I use 40:1 with top grade oil and non additive unleaded gas in my older 2 strokes. Others may have different opinions about the mix, depends on type of fuel, type of oil and whatever works for you. 

Do you know if the fuel tank has been sealed internally? The fibreglass will soon start to react with modern petrol if not.

7 hours ago, oldaz said:

Had to go to shop, but capacities I have are - clutch = 200 cc 10/20w or ATF, gearbox = 300cc 10/40w or 75w (should be a GL4 oil due to brass/bronze parts in there), forks = 190ml 10, 20, or ATF (use different weight oil to suit rider, but action should be "soft" compared to dirt bike), original mix is 25:1 with engine oil, but modern synthetics can run up to 50:1 - I use 40:1 with top grade oil and non additive unleaded gas in my older 2 strokes. Others may have different opinions about the mix, depends on type of fuel, type of oil and whatever works for you. 

Thanks so much for going through the trouble to get the capacities much appreciated, not sure who sells non additive gas anymore more research

3 hours ago, cleanorbust said:

Do you know if the fuel tank has been sealed internally? The fibreglass will soon start to react with modern petrol if not.

Really not sure I'll have to ask
Would using non-additive gas like cleanorbust suggested aliveat that problem?

Being in Australia most of our gas is non-additive, not all petrol stations sell ethanol gas, so we don't have a problem and still have a choice of 3 octane levels. The general rule is if the vehicle is over 10 years old, don't use ethanol gas. Son in law did in a collector car and it cost him over $500 to get everything cleaned out and all new rubber though the gas system - took about 6 months to get the thing running right again - then he totalled it. I use 40:1 synthetic 2 stroke oil with 91 octane unleaded, it doesn't eat rubber or fibreglass, but tends to go off if stored too long.

He said that he remembers getting epoxy to seal tanks but he had a huge collection at the time and doesn't recall if this bike was done, can you tell by looking inside, or should I just get it redone?

Depends on the brand of sealer used as to weather you can see it in the tank. Some have a white or silver look and some are clear. I used Caswell epoxy sealer in my 74 247 and it is clear so it is hard to tell. The biggest thing on having success using a sealer is good preparation. Nice bike!

Nice bike indeed, and all the more so for still having the original tail silencer as opposed to one of those horrible sounding alloy jobs that they usually have by now.

2 hours ago, sdm said:

Depends on the brand of sealer used as to weather you can see it in the tank. Some have a white or silver look and some are clear. I used Caswell epoxy sealer in my 74 247 and it is clear so it is hard to tell. The biggest thing on having success using a sealer is good preparation. Nice bike!

Thanks I cant wait to pick it up, I think I'll just have it resealed to be safe