sectionone

This site claims that KTM made motors for Beta. https://www.bonecutterbeta.com/blog/beta-history

I tried swapping my KX100 carb with the Dellorto 26mm carb on my Fantic Section. It made it not run like a trials bike anymore. Not much low end and all the power is mid range. Kind of liked it. I guess using a different slide and jetting would make it more like a trials carb.

My 2007 Gas Gas has a KTM logo on the radiator. I read on some forum that KTM makes the Beta 4 stroke trials motor. Seems far fetched but Beta did use KTM engines on their enduro bikes and Suzuki engine on the Alp. Gas Gas and Sherco four stroke trials engines failed, but 12 years later the Beta four stroke engine is still going strong. I wonder if KTM gave a helping hand? https://en.wikipedia.org/wiki/Beta_(motorcycle_manufacturer) This video claims Beta makes KTM engines. See 1:10

According to DID, the VT2 is 18.70 mm and standard is 17.50 mm wide. Almost the same.

On my Gas Gas I run a standard chain since I have no choice and ride only trials on it. My 4RT is used for mainly long distance riding and like an enduro bike, an X ring chain makes sense.

You might want to check to see if it will fit in the chain tensioner. On my Gas Gas, an o ring chain would rub against the case at the countershaft but on my 4RT there is enough space. I'd like to try a narrow x ring when I need a new chain. Narrower the better. They say x ring has less friction.

I have one on my 4RT. It is not very comfortable for long range riding. Foam is too firm. To use the gas, you have to take the seat off and use it like a gas can. I improved the comfort by adding an inch of foam, covering it with leather, glued to the vinyl. The added height makes riding position better along with moving the pegs forward. For riding while sitting, you want your body position more like the 4Ride which has the pegs moved forward.

http://www.overlandtrail.biz/ I found you can search by part number on an online retailer like bikebandit.com. Spend $100 and get free shipping at least here in the US.

https://www.rickramsey.net/Montesa4RTmods.htm

If someone wanted to make their own bike they could buy a Chinese crate engine, build frame and source other parts. There's even a 2 stroke option with electric start with counterbalancer. Engines would probably cost half or less if bought from the source. The horizontal pit bike engines would have a lot of low end grunt. The Chinese even make a KTM 105cc 2 stroke clone engine which would be very light and good for trials if tuned correctly. https://gpxmoto.com/index.php?route=product/category&path=10 http://www.shinebike.com/product-detail-232309.html

Here's a quote from Ian Smith, Oset founder: Financially, lithium batteries are by far the biggest single component cost in the bikes. Ian describes it as: “It’s like buying a bike with years’ worth of free fuel.” Does this mean you need a new battery after a year if you want it to perform the same in December as it did in January? If the battery is good for 1000 charges it would be like buying a bike with 2.7 years of free fuel if you charge it every day. But of course electricity is not free. I suspect Oliver Smith gets a new battery at least every year for top performance. https://electricmotorcycles.news/oset-24-0-racing-2017/

A friend bought one last year used for $3000 and the previous owner bought it new, rode it a few times, didn't like it and sold it. My friend only rode it for about 6 months before his knee injury and now he says the battery is toast and needs to be replaced. I think it needs a new battery every 1-2 years with regular riding. At that rate, it is more expensive to own than a gas bike.

Looks like the same Chinese motor as the GG Randonne. https://advrider.com/f/threads/tenaci-wong-tw200s.1194012/page-5#post-35728112

I had a 305 and the manual was in Italian. Watch out for the skidplate bending and cracking the cases and chain coming off and breaking the case.

Replacing #10 just take off clutch cover and only tools you need are circlip pliers and allen wrenches. Older bikes like my 07 need to split cases to replace shift shaft. If your bike is old you might consider replacing all the seals and maybe main bearings while the cases are split. When I split my 07 I didn't need a case splitter tool.

The crossbar on #10 will break and spin inside the cylinder after a hard hit. My guess is #13 cracked and you have to buy the whole shift shaft assembly #28 Mine cracked after the bike slid down a rock face dragging the shifter upwards. On my 07 the crossbar on #10 is not welded but pressed in. It is like a fuse, your bike will shift if it is good or won't at all if broken. After it breaks you can tap it out and replace it. I found a piece of deadbolt wood frame reinforcer fits perfect and I keep it as a spare.

https://www.ebay.com/itm/Vee-Rubber-VRM308R-Trials-Rear-Tires-3-50-R17-TL-Radial/183216783167?epid=656466914&hash=item2aa8923f3f%3Ag%3A-tkAAOSw3qZa8mot&_sacat=0&_nkw=vee+rubber+3.50-17&_from=R40&rt=nc&_trksid=m570.l1313 My guess is same rubber.

I have a bike that has oil leaking from the countershaft seal. Parked in the garage, I would find a small puddle of oil on the floor. Now I use a triangle stand and park the bike leaning in the other direction. Problem solved!

How much did it cost for the cylinder exchange? I assume it is from Jim. I just had my YZ welded and replated and it cost me $320 with shipping plus $100 for new piston.

Before I open an engine for the first time I look for any evidence of someone opening it up before me. Rounded bolts, scraped off gaskets, marks from removing seals, etc. I doubt a backwards piston would last 14 years. It will cost about $300 to get the cylinder welded and replated plus the cost of new piston. If you have any up and down play on the rod you should have the crank bearing replaced and while your doing that, replace main bearings and seals. Another $500 or so. Up and down play on the rod will toast a new top end, side to side play is normal. I guess totally rebuilding the engine will cost about $1000.

I remember when you were having Ducati ignition problems you were doing some weird wiring experiments, bypassing components. I wonder if this was the initial cause with improper ignition timing? Usually trials bike top ends don't need to be replaced even after 10-15 years for the average rider with proper maintenance and the usual putting around. I never hear of trials riders installing hour meters and talking about new rings or piston after X amount of hours like I hear enduro and mx riders do.

My radiator guard extends beyond the surface of the cdi and the cdi is not securely mounted. Sort of a breakaway mounting. I plan on making a plastic cover for it. The new Betas, Sherco, Scorpas have the cdi mounted exposed in a lower position which might be better but a mounting bracket needs to be made. They have been doing this for a few years now and maybe it is to keep it cooler but it looks to be in a vulnerable spot.

20171218_170129 It is attached with foam tape and a zip tie on an aluminum radiator guard I made. 20171218_170141 The rectifier with a heat sink epoxied on.

The Kokusan swap is the best solution and mine has been working fine for a year and a have since I stopped using Ducati. Except this summer the rectifier went out, another cursed Italian part. I replaced it with this: https://www.ebay.com/itm/TRIUMPH-NORTON-BSA-ROYAL-ENFIELD-ETC-SOLID-STATE-RECTIFIER-PN-99-9882-/401454218290?hash=item5d78893c32 I'm concerned about exposing electronics to heat so I mounted the CDI on the left side behind the radiator, next to the fan and added cooling fins on the rectifier and mounted it behind the numberplate. Not so worried about the coil so it is behind the steering head.

I bought a complete Kokusan system from trialsbikebreakersuk ebay store for $370 in May 2016. Earlier that year they had another system they sold as a kit and around that time you could also piece together a complete system. Now they seem to have dried up but you could keep checking. You could get one here if he still has it. I have three Ducati regulator/rectifier boxes that you can have for free. Also have the flywheel, 2 coils, 2 pickup coils and stator.