spokerider

Peter, Thanks for the info.........just what I was looking for. I got a bunch of different jets when I bought the carb, so I'll try the factory jetting first and go from there as you've suggested. Thanks for the tip on the inline fuel filter.......I'll get one.

I discovered using a bit of heat from a propane torch helped with the removal of the old crank seals and installation of the new ones. The new seals I bought were made by Honda and looked a tad more narrow than the old ones, and would have been tough to tap in without heat....... Wondering.......now that both side cases are off, can any of the other seals be changed? or do the cases need to be split to re and re them? I've already changed the [ outside ] shifter seal on the case.

Jon, Thanks for posting the pics. Say, would you like to trade that split bearing puller for another 3 jaw?? lol!

Well the blasted primary gear is off, and yes, it was a stuggle......... The 3 jaw puller had to be modifyied to fit the back of the gear as there's not much clearance back there. After 2 hrs of trying that puller I gave up using it. The jaws kept opening up as I increased torque, no matter what method I tried to use to secure them closed. Loaded the bike into the truck and off to my local bike repair / dealer. He's had lots of experince with the ol' Cotas from years before, and knew the stubborness of the gear well. We used a "split bearing puller", impact driver, and a propane torch. A few minutes later.......POW and the bugger was off. It literally launched itself, and the puller, across the room 4 feet when it let loose! Cripes, sure hope I don't have to do that again....... The split bearing puller was surely the correct choice.

When I get a chance, I'll take some pics and post them up. I'm certainly interested in learning more about it!

So that's what a "works" rider is...... Seems strange how a bike of this vintage has found it's way into BC Canada......... as odd as it is, it's kinda neat having it.

Thanks for the replies fellas. Now I KNOW how it is suppossed to come off, so I'll proceed further with my efforts. The 5 ton 3-jaw puller ought to work to get it loosened enought to slip off. That was one of my concerns, that a puller pulls straight out and the basket gear / primary gear requires it to twist as it comes from the shaft........ Ah yes, the dreaded primary gear........ perhaps I'll be one of the "lucky ones" where the gear just slides off like butter! lol.

Well, just finnished fooling with the bike for the last two hours, and have come to a "hiccup". I've removed the counter flywheel and am in the process of removing the clutch assembly. I can't figure out how the clutch basket comes off of the shaft. I have taken the clutch disc assembly out by removing the three wire clips, and have removed the bushing [ below the disc plates ] and three roll bearings that fit into the bushing. Now I'm stuck...... Can't see any retaining clip holding the basket in, tried gentle tapping with wood and hammer, no go. I know better than to start beating on it....... What's the key to removing it? Thanks.

It is well used........ I bought in in a non-running condition. The previous owner was going to repair and ride it, but had too many projects on the go, so selling it to me. Has good fat spark and good cyl compression. Forks appear bent / misaligned. Tank has been repaired and repainted, but is still rough. Torn seat. Fenders are not original. I haven't had a chance to try to run it, as I too have another 348 project on the go. What is a " works bike"?

Thanks for the info Dave, I'm going to go to the shop now and play.......perhaps mutter a few choice words, lol. I bought a 3 claw / 5 ton puller, so I'll see if it fits the primary gear.

Well I have the crank seals on hand, and since I don't know when they may have been replaced last, I figure I may as well change them out. I'm waiting on getting the cylinder back from the machine shop sporting a new overbore piston anyway...... Since I've never replaced crank seals before I have a few questions please...... Is the counter flywheel [ on the clutch side ] nut reverse thread? ie; turn clockwise to loosen? Does the counter flywheel require a tool similar to the flywheel puller to remove? Next, remove the clutch basket? Now, pull the primary gear with a puller.......then remove the crank bearing cap and gasket........ OK, how does the seal come out, pry out with screwdriver? Now, ditto for the flywheel / stator side....... Lastly, what torque spec for the counter flywheel nut? What torque spec for the clutch basket nut? Thanks a heap!

Hey Dave, Thanks for the reply. The headstock number is 51M 0010 Perhaps this is a very early 348? The engine sure looks identical to the other 348 I have......... Thanks for clearing up significance of the numbers stamped n the case halves on the rear mount boss.

I picked up a spare "parts bike" 348 last week. I'm trying to figure out the date of manufacture by the number stamped on the engine, but, the problem is, there is no 51M number [ or any markings here ] stamped on the case below the carb bowl, instead, the only numbers I can find on it are "1313" stamped on the cases at the rear mount / bolt boss. Otherwise, it sure LOOKS like a 348 engine....... Thoughts?

Anyone done this?

Today I cut a flap of metal from the back side of the 348 silencer with a grinder and thin cut off wheel. Not a thread of glass inside, and it was fairly clean inside with all of the lye and burning I'd previously done to it. Packed some woodstove fiberglass door seal into and around the baffle tube and replaced the flap with a piece of .050" metal. Mig welded it up and ground the welds down flush with the grinder. You can barely tell it's been opened....... Only took a few hours total to complete and seems to be time well spent.......

Wondering at what rpm the 348 makes it's power. In the manual, there is a graph that indicates speed vs rpm for each of the six gears, but no indication of the power band curve.

Well I cleaned the rear silencer with the lye / water mix and then used a propane torch to burn all the oil residue from the thing. Lots of stinky smoke....... Anyway, it sure "breathes" well without any constriction when I blow air through it. A question about the glass packing.........is it there strictly for "silenceing" the sound or does it have a purpose having to do with backpressure and correct engine breathing etc? How large of a flap of the silincer needs to be removed to gain access to the inner old glass packing to remove and replace? Is the effort worth the benift? Anyone have a pic to share? I'm at the stage of sanding and about to paint the exhaust.......

My 348 has the same problem........the fiberglass tank is burnt / melted from the heat of the exhaust touching it. The airbox is somewhat melted from the heat too. I'm in the process of sanding the exhaust pipe and sillencers now, and will soon paint them with Tremclad Hi Temp flat black paint. I'd like to sand and repaint the gas tank next. There are a few "JB Weld" repairs on the tank side that some previous owner has done to patch some holes, as well as the burnt area that'll need to be reinforced with epoxy and some woven glass cloth. Otherwise the tank is in good shape. Good idea on using asbestos or fiberglass cloth on the inside of the tank to insulate from heat. I'll have to come up with something similar too.

I just bought a Keihin PWK 29S carb for the Montesa 348. This is the 28mm carb. Can anyone provide info on jetting this PWK for my application? The oem jets in the PWK carb are: Main # 135, Slow jet # 38, Jet Needle 46JJH. The carb also came with a bunch of other sized main and slow jets to tune with. Thanks.

Thanks for the reply. I tried burning out the oil residue with a propane torch for 40 mins today, as well as the soda soak yesterday. I'll see how that goes, if not sufficient, I'll cut out a flap, re and re the packing and weld it back up. It likely never been done before, so it can only help rule out any exhaust / constriction complications.

Did a search, still have a few questions please.......... I'm trying to clean the exhaust silencer on the 348. Tried the caustic soad soak x 24 hours......very little if any grunge came out. Still looks oily inside. What is inside a 348 silencer for packing? Thinking of trying a propane torch and burning any crud out. Seems others have cut through the silencer and replaced packing material.......but on a 348?? Not wanting to spend $200 plus on a new one at this time. Thoughts? Want to paint the exhaust system with high temp black paint following cleaning.

The manual says to torque the cylinder nuts on a Cota 348 from 14.5 to 18 ft lbs. My torque wrench starts at 20 ft lbs. Don't really want to have to buy another torque wrench [ another $50 ] ......... what do you guys do? Calculated *guess* when tightening? The cylinder head will be torqued 22 to 25 ft lbs, so I'm OK there.......

Well, after 5 days of soaking in penetrating oil and tapping sharply [ x 4 days ] with a brass drift, the cyl hex nuts came loose without any trouble at all........ Thanks for the great tips guys!

I see the length of the PWK 28 is 83mm. I haven't measured the length of the Amal MK II yet..... http://www.keihin-us.com/am/products/pwk.php And the Amal MK II is 93mm.......... Looks like I need either of the rubbers to be 10mm longer or I modify the airbox hole to be 10 mm closer to the carb and use the oem airbox rubber.