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The tops on the Champion 8405 plug do not screw off.

Identifying the "best" plug is a little like selecting the "best" twinshock. Standard NGK's are great, but I've had better results over the past couple of years using Champion PowerSport 8405 plugs in my 348 Cota's. Here is what Champion says about the PowerSport plugs. "Champion PowerSport spark plugs are designed to deliver unmatched performance. These plugs are specifically engineered to increase power and reduce fouling in PWCs, snowmobiles, motorcycles and ATVs. These high performance plugs provide more power for quicker acceleration and less fouling providing faster throttle response. Champion's technology offers a variety of innovative features including the increased bore volume between the shell and the core nose to promote better scavenging of deposits that cause fouling. The Champion-developed Mag Suppressor controls damaging RFI (Radio Frequency Interference) without reducing ignition performance. Projecting the core nose past the shell results in reduced misfire and more stable combustion. The Champion exclusive copper core ground electrode runs over 200

Not sure whether or not it is available in the UK, but I have always used Rust-Oleum Semi-Gloss black. It is in between gloss and satin and very closely matches the original engine paint.

If you are interested in an upgrade, go to 'Pyramid Parts' on the inrternet. They offer a tapered bearing set for the Cota 348.

Pertinent specs for the Cota 247 are as follows: Cylinder bolts - 18 lbs ft Cylinder head nuts - 25 lbs ft Flywheel - 72 lbs ft Primary drive flywheel - 72 lbs ft Not a torque, but ignition timing is: Before serial number 21M3000 - 4.00 mm (0.157 inch) After serial number 21M2999 - 2.50 mm (0.098 inch)

Scorpa250 Sorry as this will be too late for your repair, but in anticipation of the next one who suffers a similar fate, I repaired my 270 Rev 3, which looked much worse than yours, with some epoxy and patience with a Dremel tool.

Clutch side flywheel is on a straight shaft (no taper). Clutch drive gear is on a taper.

If I can add my two cents, it really does appear to be a 348T with the rear portion of the tank removed (cut off) to accommodate a 348 seat.

The Montesa service manual makes no mention of using, or not using, anything on the gasket. In fact the only mention of the gasket is this ... "Always use a new cylinder base gasket upon reassembly". That is the "official" word. I personally have always used Permatex 85249 Hylomar Universal Blue Racing Formula Gasket Dressing on all engine gaskets where the the manufacturer does not offer a specific recommendation.

There is currently (5/13/10) a 1984 350 Montesa Cota on E-bay, with pictures. Search item # 110530357747, or just search on Montesa under Motorcycles.

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.

Ensure that the thrust washer, item 90, part number 13-38360, in your parts diagram is in place between the inner and outer clutch baskets. Without it the clutch will drag.

Hard to understand the design (location) of the fuel tank filler cap. It would appear you have to lay the bike down to avoid spilling fuel and completely fill the tank.

Identifying the "best" plug is a little like selecting the "best" twinshock. Standard NGK's are great, but I've had better results over the past couple of years using Champion PowerSport 8405 plugs in my 348 Cota's. Here is what Champion says about the PowerSport plugs. "Champion PowerSport spark plugs are designed to deliver unmatched performance. These plugs are specifically engineered to increase power and reduce fouling in PWCs, snowmobiles, motorcycles and ATVs. These high performance plugs provide more power for quicker acceleration and less fouling providing faster throttle response. Champion's technology offers a variety of innovative features including the increased bore volume between the shell and the core nose to promote better scavenging of deposits that cause fouling. The Champion-developed Mag Suppressor controls damaging RFI (Radio Frequency Interference) without reducing ignition performance. Projecting the core nose past the shell results in reduced misfire and more stable combustion. The Champion exclusive copper core ground electrode runs over 200

Gearbox uses 300 cc (10 oz) of SAE 80W 90. Clutch uses 200 cc (6.75 oz) of 10W30. In both cases any good motorcycle oil will do.

I'm not sure about the UK, but here in the States, fork, engine, and transmission seals are readily available at any decent industrial bearing supply house, and at considerably less cost than through a motorcycle dealer.

Whether or not this is correct is open for discussion, but I've always believed that when installing two seals in one leg, the first (bottom) seal is installed with the open or spring side of the seal facing down to wipe off oil. The second (top) seal is installed upside down (spring side up) to wipe off dust / dirt and protect the bottom seal.

Here is an old Bultaco flywheel tool that I've used since the 1960's. It works great on different size flywheels and as requuired could be made locally.

It's been mentioned before but if you want to eliminate clutch drag on a Beta Rev 3, deglaze the clutch plates, and if you know someone who can do it, have the metal plates knurled. To deglaze the friction plates place a piece of 150 grit paper on a piece of glass or some other flat surface and lightly rub the friction plates over the sandpaper in a figure 8 pattern. Roughen them up just enough to take the glaze (shine) off them. Of course replace any warped plate. Deglazing every 5 or 6 events will ensure that you can find neutral with the engine running. Using ATF oil will also help reduce drag, but it tends to make the clutch a bit grabby.

I agree with Feetupfun on the fuel supply, had some of that with my Metralla. I'd also suggest you replace the crankshaft seals. Here are some restoration tips that I've had in my Metralla file that may be of value to you. Sorry if the original author happens to read this, but I've lost track of where I found them on the internet. RANDOM RESTORATION NOTES: Shocks & Front Forks: Both rear shock & front fork springs are single-rate rated at 50 lb. / in. compression Spring dimensions: Front Fork: height: 198.2 mm; outside diameter: 41.93 mm; inside diameter: 31.15 mm; spring wire dia.: 5.39 mm Damper Fluid: Hugh's Bultaco recommends 5 wt. oil for the original Betor shocks. Fork oil spec from the owner's manual is 30 wt., John Sommerville recommends 40 wt. for un-worn forks. (I used Bel-Ray fork oil & shock oil) Carbs / manifolds: For engine s/n's M23.00.001 - M23.01.470: 27mm Amal Monobloc w/ straight manifold, s/n M23.01.471 through M23.03.890 30mm Amal Monobloc w/ straight manifold, after s/n M2303891: 32mm Amal Concentric w/ 'gooseneck' manifold. Bare frame weight = 30 lb.(!!!!!!); Swing Arm = 6 lb. Metralla Brakes (160mm) - 6.30" x 1.6" - Brake Swept Area: 31.65 sq. in. - Radius x S.A. (braking coefficient): 99.69 sq. in. Flanders Company has a Motion-Pro petcock (p/n 121-12039) that works well for the oil petcock to the fuel tank. It has a fairly large I.D. that allows the oil to flow when pushing the pump piston without as much "shove" as a standard "on-off-reserve" one. The 1/4 in. NPT threads that it has can be easily cut down and a 12 X 1.5mm die run down it to fit the tank threads. If you're missing the rear sprocket cover, contact Peter at Butaco Parts Australia. He provided fiberglass replicas that are near perfect. Tire selection turned out to be Avon "Universal" race tires - 80/90-18 on the front & 90/90-18 on the rear (although this is considered a bit large for the stock WM-1 rear rim, but seems to work fine). 28 PSI front & 30 rear seems ball-park for an 85 kg. rider. The Metralla owner's handbook calls out the ignition timing spec. as 3.5 - 3.7mm BTDC, this may be because of the availability of 100+ octane fuel at the time. In actual use this is far too advanced and produces pinging, overheating, hard starting and reluctance to accelerate in higher gears. (update) - with the carb jetting that I ended up with below, I decided to try a little more advance & am running it at 3.2mm BTDC. With that timing and the jetting below it seems to actually start more easily than before and revs a little more freely with no tendency to ping when it gets hot. I'm running Chevron 94 octane unleaded & Belray SI-7 oil @ 32:1. The lock ring that holds the air filter into its plastic housing will likely pop out when you're clipping along at 100k since it gets pretty "buzzy" up there. Drill 4-5 small holes (1/16" or so) around the circumference of the air filter housing next to the clip groove then after installing the clip, use some loops of lock wire to secure it. If you're using the oil pump, be sure to install "Viton" 'O' rings on the plunger if you plan to use synthetic 2-stroke oil. Synthetics seem to swell conventional 'O' rings and seize the piston in the plastic housing. If you install a primary chain tensioner, stock or Sammy Miller, the roller will fail in a few hundred miles. The roller has no other bearing surface on its pivot pin other than the rubber that it's made of causing the roller to come apart. I've installed a Delrin roller with ball bearings to fix the problem - at 400 or so miles the Delrin roller shows no wear at all. I found the stock Amal 32mm concentric jetting to be close, but not quite right for my sea level - 20-25 deg. C location. I ended up with the following for carb settings: (update) MJ: 230; PJ: 35 (a little richer than the stock # 30 - easier starting, & does not tend to die without revving with warm starts); needle jet: 107; needle: 'X' @ middle clip position; slide: #3.0; air screw: 1.5 turns out. Arriving at the correct jetting was a hair-puller that turned out to be partly because I was sold a replacement needle jet that was marked as a #106, but very worn to the extent that it was a lot larger than a # 107. Figuring this out took a while, but once an actually new, correct size # 106 NJ was installed (thanks to Speed & Sport) it ran much better, but still needed a #2.5 slide to keep from pinging @ 1/4 throttle when hot. The #107 NJ & 3.0 slide seems to be the best combination so far. Feeling such a noticable difference with only a .001" increase in NJ size confirms why it's recommended to periodically replace the brass NJ due to wear from the steel needle. These jetting figures are with a stock 8.5:1 CR head. If you're trouble-shooting starting or running problems, you'll probably want to do a bottom end leak-down test. I built a rig shown here. Pump up to 6 PSI with the piston at T.D.C. - no more than 1 PSI loss per minute is OK. Two things that I wish I'd done while the engine was going back together: (1) Chamfer the LH case at the kick starter shaft boss & shaft bushing to allow installation of an 'O' ring. I incorrectly assumed that the seemingly small amount of clearance between the k/s shaft and case wouldn't allow gearbox lube to leak, but it did. I had to resort to a specially made bushing and 'O' ring installed from the outside - not the best way to seal it. (2) Hugh's and others have a "slick-shift" selector drum available. The standard shift set-up is pretty clunky & false neutrals are routine This mod is supposed to improve things.

In Canada Sunoco is a trademark owned by Suncor Energy Inc. Suncor Energy Inc. is the parent company of Suncor Energy Products Inc. who market under the Sunoco brand in Eastern Canada. Sunoco Inc. is the U.S. based manufacturer of petroleum and petrochemical products marketing under the Sunoco brand in the United States and operating worldwide. Sunoco in Canada is unrelated to Sunoco in the United States which is operated by Sunoco Inc. of Philadelphia, PA.

I have a '81' white 349, two '78' 348's and a '77' 348. I can tell you with absolute certainty that the 348 and white 349 tanks are not interchangeable due to frame geometry.

Just found the web address for a company that makes a bed bracket. See www.fuse-powersports.com

The easy answer would be to go to a local meet and observe how other fello riders transport their bikes. I regularily haul two bikes in my pickup and made a bed width bracket of 1-1/4 x 1-1/4 square tubing with two sets of tabs to accept the front tires. It's bolted to the front of the bed.

A couple of thoughts, in order of probability. 1. Kinked or misadjusted clutch cable that holds the clutch in a partially disengaged position. 2. Worn clutch plates. Depending upon where the piston is on compression, when kick starting, the clutch may slip 3. Worn, broken, missing ratchet teeth on the kick start ratchet gear. Check 1 and 2 first, as number 3 requires splitting the cases.