feetupfun

Do you mean XC TING riding gear?

Dave your M49 page using the link in this topic wont load properly for me - there seems to be multiple pages of text and photos all on top of each other. I'm using MS Internet Explorer. Regards David

Here are the best photos I have showing the engine cradle area of early M49s.

Dave, Bultaco didn't identify different series within a model designation and neither did Montesa, but since then people have created series designations as a way of making communication about them easier. Bultaco made the M49 for about three years with lots of changes along the way and they are all just M49 as far as Bultaco was concerned. Montesa made the Cota 247 for about seven years and changed lots of things along the way but they are all Montesa 21M. Woody is just referring to the production records showing that the frame tube arrangement under the engine changed at frame number x. The frame number record for the change to the top shockie mount location was probably just not considered imporant enough to record or has been lost over time, but is probably a worthy goal to find out or work out if we can somehow.

Thats right Wayne and I'm sure it was pretty frenetic in the factory and they had the philosophy of making improvements to a bike as soon as it was possible rather than holding off changes till the next years production run. It shouldn't be a surprise that the M49 frame looks like a M80 frame. The only differences I can think of are the mounting points for the seat/sidecovers and mufflers.

Wayne I just looked in Historia de la Sherpa T and the text there says "A new chassis comes into production from bike number 4902426 onwards. Previously, the mudguards and the engine's outer cases had been modified"

Wayne the numbers on that bike matched but there is no guarantee the magneto cover hadn't been replaced. I do think though that the magneto covers changed to the M80 type at some time during the M49 model run as I have seen plenty of other M49s with the M80 type magneto cover. My series 1 M49 has the older mag cover with the multi-start thread clutch release mechanism but the clutch has a surprisingly nice action. When I first got the bike I was worried it would be inferior to the later, cam type clutch actuator with the arm on top. David

Here is a photo of a Series 1 M49 for reference purposes showing the more upright shockie positioning. Serial number M4900100

Here are the M49 Series 3 photos. Serial number is M4902517. I put the handlebar clamp photo in because I wanted to show why many people replaced the top steering yoke on their M49 for one with a better clamp.

I visited a bike boneyard to look at two M49s and luckily they were examples of a series 2 and a series 3 bike. This posting has the photos of the series 2 M49 serial number M4902195 and the next posting shows the other bike. What got me motivated to go looking was a post by Woody: "The serial numbers are from Bultaco's own figures so they should be right. However, they only list the model 49 as having one frame change during its production run but there were two. Series 1 with single tube under engine, upright shocks. Series 2, single frame tube under engine, angled shocks with seat unit altered to accomodate relocated top shock mounts. Series 3, twin frame tubes under the engine, like the M80 and which was the basis for the Kit Campeon."

Way less than 33 BHP. I would estimate about 15 BHP.

There are no hard and fast rules for this. One of my friends only ever uses first gear for absolutely everything (250 Majesty) and another only ever uses third gear for absolutely everything (240 Fantic). If you can develop good enough technique with the clutch, you can use a higher gear than if you are a bit gumby with the clutch. That way you can use second or third even in tight stuff and still have great speed potential for big ups. Another thing is that if you get your bike running so it revs out cleanly, you can get high ground speed even in first gear. This is one of the technical advantages of a well set up four stroke - they generally have a greater range of useful RPM than a two stroke.

Many years ago when petrol could be stored for weeks and seemed to work well, it was drummed into me that it was important to leave the addition of the oil till the last minute for the best results from the brew. With the pump petrol we get here, it goes to crap so fast that it is now quite irrelevant when you mix in the oil. If straight modern petrol or premix is more than 2 weeks old, it goes into my car fuel tank.

I've found you can keep things under control better during the straightening if you leave the axle in place - this reduces the risk of the arms being bent sideways. Another thing is that to do the bending you can usually use a bar positioned under one arm and over the other rather than a bar on each arm. Some bikes you can get the bar in position with the wheel still in place but for some others you will need to make a spacer up to replace the wheel so the axle can be left in place tight. Depending on how difficult it is to clamp the bike down, it may be easier overall to make a fixture to hold the swingarm and swingarm axle while you straighten the swingarm. Last one I did the frame and the swingarm were both twisted so I made a fixture that clamped the bike via the swingarm axle ends so I could straighten both the frame and swingarm at the same time.

Yes the 1970s twinshock trials bikes are fine to commute on. That's what lots of people (including me) did with them when they were new. Some are more comfortable than others. If you are talking standard seating, the most comfortable standard bikes are OSSA MAR, C, D and E model TY250, all TY175, TL125, KT250, Mk 2 and 3 Cota 247. Standard Bultaco Sherpa Ts and Cota 348/349 are at the ouch end of the spectrum. Any of them can be made much better with improvements to the seat foam and cover. I have put nicer seats on my M49 Sherpa T and TY250A and can ride them all day in comfort sitting down. Here's a picture that shows the difference. The TY250A has a slightly thicker seat and the TY250B has a standard seat.

I think it would have been good to take the bend out of the top frame tube while it was apart.

I've seen a TY with a shortened muffler from a Suzuki RG250 (1980s twin cylinder 250cc road bike) Any YZ/RM/KX/CR two stroke end muffler should work with mods to make it fit the TY. The main mods are to make the pipe the right shape to fit past the shockie and provide clearance for the tyre. Ideally get a muffler from a bike that has the pipe on the inside edge (when fitted on the RHS of the TY) to maximise tyre clearance.

Yes a guy in my local club recently modded the steering head angle on his TLR250 and reckons it is better. Don't know the angle he aimed for but you may get the answer from him on this forum or if you post ont the trials.com.au twinshock forum. I know he cut and rewelded the frame at the steering head. If you do similar you will be reducing the wheelbase and may get more grip as a result.

(the 247 with the aluminium guards) Top shock mounts moved Edge grip strips fitted to footpegs Maybe rear frame loop bent up a smidgin 348 style front mudguard mount A decompressor and a partridge in a pear tree

The only ones I've seen for TY80s are the Betors that John Cane sells. I haven't bought any yet but logically they would have to be light years ahead of the standard TY80 Yamaha shocks.

If its the same thread size as an OSSA you can buy them (aluminium inserts for welding in place) off the shelf from Keith Lynas in the US. I will go and check the sizes of both. Yes I just screwed an OSSA header nut into a Bultaco M27 barrell - perfect fit.

Sounds to me like at least one gear has siezed. Thats all it takes to get your symptoms. Hardly unusual if ridden without oil. You won't know the complete extent of the damage until you split the cases.

No its not true. I just bought a piston kit for my 250 MAR and was offered a choice of two brands by Keith Lynas in the US.

Dave I will be getting the numbers from two more M49s just after Christmas at a rellies place which may help with when the changes were made for that model. I think one is a series 3 and the other series 2. David M49-00100