Cota 348 - Help For Newbie!

[bpilgrim]

Hello everyone,

I picked up my 'new' Cota 348 yesterday, I don't know what year it is, and I don't know how original it is, maybe it's a bit of a mongrel?

The matching chassis and engine number is: 51M13030

I'm also slightly puzzled with the gearbox, just by pushing it round (with the plugs out), the order is N 1 2 3 N (I think) so, I'm guessing 4th has gone?

The forks were seized when I got it, since then I've managed to free them, but I'm unsure if there are parts missing, are the top of the forks supposed to be open? There was a little bit of water in mine.

Finally, the coil has melted because it doesn't fit on the bracket (it fouls exhaust) so someone has put one bolt in, and it has come loose at some point and melted, I have found the same type on eBay, but does anyone know of where I can get one that fits properly? Also, the wiring to the coil, some wires have simply been snipped and are not being used, but a green has a crimp on it, does anyone know exactly how it should be wired?

Any tips on what to check to get a spark would be much appreciated.

Now for the possibly silly questions:

Is the kickstart supposed to disengage when you operate the clutch?

Why are there two spark plugs?

Are the pegs supposed to be so far from the pedals?

Thanks in advance, Ben

(newbie, when it comes to old bikes)

[tony283]

Yes, it is a 348 but you have a lot of rectification required!! The coil has been fitted backwards which is why it touched the exhaust. Like wise the front mudguard bracket is on backwards,and that has meant the mudguard touched the exhaust as well. The correct position with the bracket reversed will put the brake cable in the correct alignment. Also the brake anchor is incorrect and you will need to find another. The Carb looks like Mikuni whereas the original was an Amal. Kickstart needs to be replaced as does the engine sprocket and no doubt the rear and chain as well. Rear brake? Adjustment looks way too far forward on the actuator arm. Footrest positions are normal but to may want to lower them and put them further back. The two plugs you have are not normal as the lower one on the side is where the decompressor should be or a blanking plug fitted. Rear shocks look longer than standard ? Do check the carb to engine rubber inlet as they perish and crack.

Best of luck

Tony

[belldane]

Hi I have a 348 similar to yours, eng no 45 something something and was built in 78. My guess is that yours was probably built in 79 before Montesa started building the 349's.

Your gearbox problem could be one of two things. Either gear shift drum needs to be adjusted by taking left hand cover off and centering a small cam lobe on the top right hand corner or the worst is a broken main shaft in the gearbox in which case you will need to split the cases to see what the problem is. By the way 348's have 6 gears.

I am not sure what you are saying by "the top of the forks being open"?

From the pictures you have provided I reckon the coil may still be OK. You can only try after you put it in the right way and does not foul anything.

The green wire is for the lighting. If the bike is not going on the road don't worry about it. The only wire you have to worry about is the black one which comes out of the engine and connects to the terminal on the coil. Just bind all the other wires with plastic tape and tuck them away somewhere out of the way. Set timing at 1.8 mm btd and points between 15 to 16 thou and see how you go. I am happy to help if you need it. Just PM me

[perce]

I'd agree with Belldane re the date for your bike, I've one in my garage that was registered in August 1979 & it has a number within 100 of yours. I think the wheels belong to a later bike as I think the first gold rims wouldn't have appeared until 1980/81

[dabber]

Front hub isnt a 348 and the kickstart is off a 200. (maybe where the wheels cam from)? Seems like an early frame without the 'lugs' either side of the front of the bashplate.

[bpilgrim]

Hi,

I have just received an email from In Motion Bultaco, I sent a question about the decompresser kits along with my chassis number, he's put a year of 1977 on it, but said they stopped selling the kits as they went from

[tayld]

Hi there,

Looking at your pictures the front wheel is from a 1982-on 349 Cota or the near identical MH349. This brake works well but it is worth checking the larger spoke flange for cracks starting at the spoke holes.

Your fork cap nuts may have lost their innards. Two types are prone to this, one type is fitted with an air valve (this type is on the In-Motion website in the Montesa section) the other type was fitted to late model 349's and the 330. The second type is vented to the atmosphere by way of a very small hole drilled in each of a stack of four dished cups pressed in from the bottom of the nut. The dished cups can be pushed out rather too easily at times. The later type can be seen on the Billet Parts website.

A set of forks we had with the air valve type nuts also seemed to have softer springs. Nuts and springs are interchangeable so it is worth trying to get a pair of nuts to match the springs you have to save some money.

When you get to the point of running the bike treat it to a new air filter element (roughly

[belldane]

Fitting the right kick starter will certainly stop the side cover from being destroyed any more. As far as pulling the clutch in and trying to start, it will never happen. The kick starter will just slide down without turning the engine. The bike has to be in neutral before it will start. As far as buying all the bits and pieces to get it going, I would try the old coil first. Even though the casing has melted, it may still be OK and you are going to find that the new one is going to cost you an arm and a leg. What I would do is connect the black wire coming from the engine to the coil, replace the condenser and the points. (set the points between 15 to 16 thou) and give it a kick and you should get a spark. (make sure that you earth the plug on top of the head as you are doing that). The fun and games will begin when you try to sort out that gear problem. Hope that helps

[nh014]

The paint codes for the 'Montesa' red on the tank are:

Lacquer-

Dupont Lucite Acrylic Lacquer

Code 75-Red

1978

Enamel-

PPG Delstar Acrylic enamel

Dar 72155SC

Fleet bright red

The frame on all 348's is black.

[bpilgrim]

Hi,

Thanks for all the info, it's been very useful, I now have a few more questions!

1. I have read that late 349's were the first with chain tensioners? Mine has got one, which has forced the chain to run against the swinging arm.

2. Coil, it doesn't fit either way, forwards or backwards, the mounting plate that the coil is on is too long, either that or the exhaust has been modified.

3. My fuel tank doesn't have a breather, and there are no signs that the tank ever had a breather, the tank also protrudes out below the side of the fairing (see pictures above), wrong tank maybe?

Now for an update; I was planning on getting the bike running first before I started the restoration, but after taking the bodged kickstart off, it was clear it wasn't going back on, the splines are non-existent! I thought about just bumping it, but with only three unknown gears selecting, I thought better of it. The bike is now stripped and some parts are about to go for paint, while I get more time to source essential parts, like a kickstart and the shaft, I have tried Inmotion Bultaco and France Trial Classic with no success, anyone know where I could find one?

Many Thanks

Benjamin

[feetupfun]

Are you trying to use that mounting plate shown in the "before"photos? or did you also get a mounting plate from In Motion? The plate in your photos looks wrong to me. If you can wait a few days I will take a photo of what a 348 coil mount should look like.

That chain tensioner may or may not be from a late 349, but the reason the chain has been rubbing is that it is adjusted way too loose. On my 348, I use a chain tensioner mounted to the motor in a similar way to that on yours, but mine has a shorter arm and works perfectly - bought from Jared Bates in the US.

Your tank may be fine sticking out like that. I don't know for sure because our tanks (Australia) are a one-piece fibreglass item. What you have there with an aluminium tank under a fibreglass cover is what was sold in the UK. However it looks like the correct shape cover to me for a 348.

Don't give up on your kickstart shaft and lever. There should be plenty of 348s around that are not worth fixing up and it is rare to see problems with the kickstart shaft spline and lever so you should be able to get one from someone wrecking one - even if you have to buy the whole motor to get it.

Some caps have a breather built in and maybe your tank should have one of those caps. Can you do a better photo of the cap? The one-piece fibreglass tank 348s like mine have an obvious breather tube coming through the fibreglass ahead of the cap, and the cap is non-vented.

[bigshineybike]

Re the coil, theres one for sale on ebay at the moment.

It claims to be for a 348 and does look exactly like mine. Ebay number 280505617518

My alloy tank sticks out same as yours although mine is a 349 tank in a 348 Yellow GRP cover.

my 1978 one piece red GRP tank has a fitted breather within the GRP.

My Alloy tank also has a welded in breather tube.

Re, the kick start shaft, you will not be able to push start the bike in some of the places where the engine will stall.

Alex

[bpilgrim]

Time for an update I think, since the bike is almost complete.

- The gear problem was indeed the gear selector mechanism, the previous owner had been fiddling and must have put it on incorrectly, I just followed the manual and I now have 6 gears selecting well.

-The tank was a 349 tank, it was shorter and wider than the 348 tank. It also had no breather and the filler was in the centre, I've now got a 348 tank with the offset filler and breather, fits nicely.

-The wheels I have been told were from a MH349, the rear had the orginal 30 ish year old MT13 tyre on! I now have an original set of 348 wheels.

-The carb was indeed a Mikuni, an Amal L2627/402 is now on it.

-The front brake torque arm appeared to be galvanised steel strip that is used for securing joists together, I've now got a proper aluminium one.

-Got myself a decompressor for the second port, which makes a great sound!

-Frame powder coated back to black instead of red.

The timing and points gap you mentioned work a treat, the bike has tonnes of power, it pulls like a tractor!

I eventually managed to get myself a complete 348 engine which is in great condition, but as I want to keep matching numbers, I'm going to pinch lots of parts from the spare, instead of swapping engines. I haven't got around to doing this yet, but at least I now have the parts ready. The old melted coil still worked, so the new one is just kept as a spare, mainly because it doesn't fit, I'll need to trim down the bracket.

Now for the project cost (ouch!), I bought the bike for £280, and the total cost so far (bike + parts) is currently at £1050 This does however include quite a lot of spares, I tend to just buy 348 parts in case I ever need them, somehow I have ended up with with 3 cylinder heads, 3 LH engine cases, and lots of spindles! I'm sure they'll come in handy one day!

Main bits left to buy/do:

-Strip both engines to make one good one.

-Shocks

-Handle bars/amal levers

-Mudguards/fairing

Here's the album of pics (you may notice some mistakes I made in the rebuild, such as the rear engine mount on the swinging arm, I put it on the wrong way, which I only found out when I couldn't get the engine bolts in!)

https://www.facebook.com/album.php?aid=59664&id=1497248461&l=b591644882

Thanks again for all your advice, it came in very handy!

Ben

Edited March 23, 2011 by BPilgrim

[thedktor]

Hello Ben,

Great job you've done there - I'm in the process of doing my 349 but focusing on the engine which has needed a complete rebuild!

May I ask where you got the de-compressor from? I also went to order one just as the price jumped, so didn't...

Cheers

Steve

PS sorry all to resurrect an old thread.