Hi there, Ive just bought a Montesa trialsbike with a view to restoring her to properly learn trials of the motorised variety ( I've been riding pushbike trials for about 4 years odd now ).

To me it looks to be a very early 80's Montesa (MH) 200, and the engine number reads with a 29M prefix ( see attached pics ) I cannot find the chassis number; ive checked the headstock but there seems to be no sign. I know the bike is a bike of a state / basket case etc but it was an alright price ( read: impulse buy ) and i really wanted a good winter project to ride next season if at all possible.

I also have a spare engine, pretty similar Monty lump, but with the clutch actuator coming out of the bottom of the engine with 28m serial number which I think is a Cota 123? Are any of the parts compatible with the 29m lump do you think?

The bikes a non-runner with, as i understand , the classic kickstart slipping problem. I pulled the casing and found both oilite bushings were pretty destroyed; the internal one was out by about .7mm and had a crack through the top-hat part of its anatomy while the external bushing was loose by about .4mm. I've machined two new phosphor bronze bushings and its massively better ( 1/1000th " / 0.02mm clearance, is that about right? ) but quite stiff. I assume this will wear in. The good news is it doesnt seem to slip now, but my little cant kick it over .

Hopefully the rest of the engine will be fine/ easily recoverable and hasnt got any gearbox damage ( which is quite common? )

At present I'm missing the rear mud guard, which i should be receiving shortly once it gets dug out of my mates shed, the seat also needs replacing....but more importantly the air box is absent. Is there anywhere to source one? Tried all the websites I can ( in motion etc ).

Hopefully you lot should see all the pictures of the Monty and spare engine below: Pictures will be posted up shortly

I'll update the topic as I make any progress / hit any problems.

I look forward to your advice / comments.

Thanks,

Alex

Edited September 11, 201114 yr by dark_biker

Hi there, Ive just bought a Montesa trialsbike with a view to restoring her to properly learn trials of the motorised variety ( I've been riding pushbike trials for about 4 years odd now ).

To me it looks to be a very early 80's Montesa (MH) 200, and the engine number reads with a 29M prefix ( see attached pics ) I cannot find the chassis number; ive checked the headstock but there seems to be no sign. I know the bike is a bike of a state / basket case etc but it was an alright price ( read: impulse buy ) and i really wanted a good winter project to ride next season if at all possible.

I also have a spare engine, pretty similar Monty lump, but with the clutch actuator coming out of the bottom of the engine with 28m serial number which I think is a Cota 123? Are any of the parts compatible with the 29m lump do you think?

The bikes a non-runner with, as i understand , the classic kickstart slipping problem. I pulled the casing and found both oilite bushings were pretty destroyed; the internal one was out by about .7mm and had a crack through the top-hat part of its anatomy while the external bushing was loose by about .4mm. I've machined two new phosphor bronze bushings and its massively better ( 1/1000th " / 0.02mm clearance, is that about right? ) but quite stiff. I assume this will wear in. The good news is it doesnt seem to slip now, but my little cant kick it over .

Hopefully the rest of the engine will be fine/ easily recoverable and hasnt got any gearbox damage ( which is quite common? )

At present I'm missing the rear mud guard, which i should be receiving shortly once it gets dug out of my mates shed, the seat also needs replacing....but more importantly the air box is absent. Is there anywhere to source one? Tried all the websites I can ( in motion etc ).

Hopefully you lot should see all the pictures of the Monty and spare engine below: Pictures will be posted up shortly

I'll update the topic as I make any progress / hit any problems.

I look forward to your advice / comments.

Thanks,

Alex

A MH engine will have a number starting with MH200 not 29M so the whole bike could be a cota or the MH has been fitted with a cota engine. The frame number should be on the headstock on the rhs at about 2oclock as you sit on the bike.Is the front brake hub black or silver and are the spokes the same length from side to side as the mh has a different front wheel to the cota, which is about the only difference mechanically.

three versions of cota 200

1 - white tank , amal mk1 carb , silver paralell hubs 110mm - COTA 200

2 - white tank , amal mk2 carb , black or silver hubs F 125MM R 110MM , engine protection loops at front of frame - COTA 200C

3 - red tank , amal mk2 carb , black hubs f 125mm r 110mm , protection loops , MH200

A MH engine will have a number starting with MH200 not 29M so the whole bike could be a cota or the MH has been fitted with a cota engine. The frame number should be on the headstock on the rhs at about 2oclock as you sit on the bike.Is the front brake hub black or silver and are the spokes the same length from side to side as the mh has a different front wheel to the cota, which is about the only difference mechanically.

Ah okay I will have a good look for the serial number tomorrow. The front and rear hubs are silver, both hub flanges are the same diameter on the front hub

three versions of cota 200

1 - white tank , amal mk1 carb , silver paralell hubs 110mm - COTA 200

2 - white tank , amal mk2 carb , black or silver hubs F 125MM R 110MM , engine protection loops at front of frame - COTA 200C

3 - red tank , amal mk2 carb , black hubs f 125mm r 110mm , protection loops , MH200

Mine has a red tank/seat assembly, Amal carb but i dont know which mark?, silver hubs ( ill check diameter ), protection loops, and 29M engine number which must make it a Cota 200 thats been resprayed or with 3rd version tank ? Thanks for the information.

IPB on this forum won't accept pinkbike images, so here is a link to the album with all the pictures of my Montesa, ill upload to imageshack.us and embed properly tomorrow. Cheers, Alex

http://darkbiker.pinkbike.com/album/Montesa/

Edited September 11, 201114 yr by dark_biker

FIRST VERSION WHITE TANK HAD HORRIBLE BULGES IN SEAT AREA AROUND TOP SHOCK MOUNTS , AMAL MK1 CARB SMALL + ROUND FLOAT BOWL .

COTA 200C + MH200 SAME TANK/SEAT AS EACHOTHER BUT WHITE OR RED AND RESHAPED AT SEAT SO NO BULGE , AMAL MK2 CARB BIG + FLAT SIDED

FIRST VERSION WHITE TANK HAD HORRIBLE BULGES IN SEAT AREA AROUND TOP SHOCK MOUNTS , AMAL MK1 CARB SMALL + ROUND FLOAT BOWL .

COTA 200C + MH200 SAME TANK/SEAT AS EACHOTHER BUT WHITE OR RED AND RESHAPED AT SEAT SO NO BULGE , AMAL MK2 CARB BIG + FLAT SIDED

Mine has no seat bulges and a small AMAL carb with a round float bowl

Ive now repaired the damage to the fork crowns, filed out the bad, tig'd it up and fly cut it down level with the surrounding material.

Got a whole A4 page of things to do until she's complete!

Does anyone know where i can get an airbox from for it? Or what would be compatible.... or even if it would run without?

YOU HAVE GOT 1ST VERSION OF COTA 200 , MK1 AMAL CARB , TANK/SEAT UNIT HAS BEEN CUT DOWN ABOVE SHOCK MOUNTS , 110MM BRAKES F+R , NO PROTRUDING FRAME LOOPS AT FRONT OF FRAME TO PROTECT LOWER ENG. CASES

ON YOURS .BEST OF ALL YOU HAVE GOT ALLOY TANK UNDER FIBREGLASS COVER , NO PETROL FIBREGLASS ISSUES . GOOGLE MONTESA HONDA 200 TO SEE DIFFERENCES BETWEEN THIS AND YOUR BIKE . PS DONT GIVE UP , ONE OF MINE WAS SAME COND. AS YOURS + LOOKS GREAT NOW .

YOU HAVE GOT 1ST VERSION OF COTA 200 , MK1 AMAL CARB , TANK/SEAT UNIT HAS BEEN CUT DOWN ABOVE SHOCK MOUNTS , 110MM BRAKES F+R , NO PROTRUDING FRAME LOOPS AT FRONT OF FRAME TO PROTECT LOWER ENG. CASES

ON YOURS .BEST OF ALL YOU HAVE GOT ALLOY TANK UNDER FIBREGLASS COVER , NO PETROL FIBREGLASS ISSUES . GOOGLE MONTESA HONDA 200 TO SEE DIFFERENCES BETWEEN THIS AND YOUR BIKE . PS DONT GIVE UP , ONE OF MINE WAS SAME COND. AS YOURS + LOOKS GREAT NOW .

Thanks for clearing that up Scratt! Guess its fairly obvious im a proper Noob with this

I'm getting the fibreglass seat/tank sent off to my cousin who works in body repair fairly soon, and tomorrow im going to try and get her running if possible.

Thanks for the encouragement dude, any chance of a picture of yours before and after?

sorry didnt take pickies b4 , during or after . will do on next cota 200 , ally swingarm , bigger engine , smaller + lower tank/seat unit with alloy tank underneath

sorry didnt take pickies b4 , during or after . will do on next cota 200 , ally swingarm , bigger engine , smaller + lower tank/seat unit with alloy tank underneath

Ah thats a shame, I look forward to seeing the next resto you do!

Does anyone know how to pull the forks apart? I need to weld mine and i simply cannot get the lowers off

So... managed to get the fork legs off, welded a new brake mount on.

Next job is to get her sparking, could not get one at all. I have replaced the wiring from the magneto, and cleaned up the earth point on the frame. Got a new spark plug too, just need to put it on and try it.

Are there any clever ways to get the flywheel off in order to clean the points? Or do I have to get a flywheel puller?

Cheers, Alex

( It deosnt have the original motoplat coil, but a yamaha one ; pictures will be forthcoming )

USE THE RIGHT PULLER ON FLYWHEEL (CHEAP ENOUGH) BULT/UK INMOTION .

IVE A 349 WITH A YAM COIL ON IT , RUNS OK . GENUINE MOTOPLAT COIL NEW