I've used the Testor's Gold Metallic enamel marker on a number of 348 tanks with good results. They are certainly not as good as die-cut decals, but I've yet to find any. With a little care you'll be quite satisfied with the marker.
See www.mid-atlantictrials.com and click on the "Local and National Trials in 2020" tab. There are number of vintage and modern trials local to Maryland and eastern PA. MAVT trials are both vintage and modern, District 6 trials are set up for modern bikes, although you can enter on a vintage bike.
A decompression valve is used for ease of starting and / or engine braking on downhill runs. In my opinion the 348 does not require any starting assistance, and it is up to you whether or not you desire it for engine braking. In 50+ years of trials riding, I could probably count on one hand the number of times I've seen anyone use one.
Correct installation is to be sure the kick start shaft is rotated FULLY clockwise and then install the kick start lever at the one o'clock position. When starting, the lever will engage around 11 o'clock and will safely rotate to the 6 o'clock position. Installed this way you will never punch a hole in the side case.
Original factory recommendation is 200 cc (6-3/4 fl oz) of 10w-30 engine oil in the clutch and 300 cc (10 fl oz) of SAE 90 gear oil in the gear box. I use Maxima MTL-XL 75wt transmission oil in the clutch and any good 80w90 gear oil in the gear box. Never been a fan of ATF for the clutch.
Here is the adjustment procedure, with credit to Steve Odell.
This is easiest to do with the clutch removed. Spin both shafts so that all 5 gears can be selected with a minimum of further turning of the shafts. The shift detent plunger and spring must be in place. Set the eccentric in the middle of its range. Now shift down into 1st and release the shift lever. If you see that the shift drum moves (ever so slightly) as you release the lever, then you need to adjust the eccentric. The plan is to have each downward movement of the lever put the shift drum in exactly the correct position. The shift detent plunger should not "assist" in rotating the drum even slightly, after you let go of the shift lever. Now pull the lever up into second gear. Release the shift lever. Once again, you should not see any further movement of the shift drum after you release the lever. If you do, then you are moving the drum too little, or too much, and that is what the eccentric adjusts for.
I've used J-B Weld, a two part epoxy, with good success on a few 348 cases. There is no problem with the design and when installed correctly the kick start lever will travel safely past the foot peg to the straight down position. Correct installation is to be sure the kick start shaft is rotated fully clockwise and then install the kick start lever at the one o'clock position. When starting, the lever will engage around 11 o'clock and will safely rotate to the 6 o'clock position.
Montesa 348 Cota. I've been riding the same 348 for 42 years, in well over 700 meets. Can count on one hand the number of times the bike failed to finish a meet.
Timing is 2.00 mm (0.079") BTDC with the points set at 0.35 to 0.45 mm (0.14 to 0.18"). There is no Montesa workshop manual. The closest you will find is the Clymer Service and Repair Manual for 1965 to 1975 Montesa 123 - 360cc Singles. They pop up occasionally on E-Bay and will suffice for the 1976 through the early 80 models.
Do a search on any of the motorcycle forums and you will find that Caswell's fuel tank sealer is the most frequently recommended sealer. I have used it on numerous fiberglass tanks with great success. Just follow the instructions on tank cleaning and application. See https://www.caswellplating.com for details.
Restored and worked on numerous 348's and never ran into plug to exhaust pipe interference. They are close, but always had enough room to drop a socket over the plug to remove it.
My memory of the sequence was 76 has the MRR signature, 77 has a fairly plain tank and 78 has a gold/black slotted line along the sides of the tank.
That is generally how I have identified them, although my first 348, purchased new, and sold to me as a 77, has the MR signature. It is serial number 5457. I've always thought of it as a very late 76 or very early 77 model.
As you can see from the number of replies, it is easy to be overwhelmed by data relative to the year of manufacture. Quite simply, it doesn’t exist, or at least like you, I’ve never found it. You’d probably be close by dividing the total 348 production of 15700 by 3, for the years 76, 77, and 78. So serial number 0001 through 5233 are 76’s, 5234 through 10466 are 77’s, and anything above 10466 are 78’s.
Any Beta experts want to venture a guess as to what happened here. Bike (2014 Beta Evo 300) locked up in third gear. Haven't split the cases yet, so don't know what we will find.
What you refer to as the brass button was originally available in six different lengths to compensate for clutch wear. Since they are difficult to find, the easiest fix is to make up a new inner cable, cut to a shorter length than the original inner cable.
348 tank
in Montesa
Posted
See picture.