mcman56

I'm not sure if this helps but have you looked at other Beta models? The 08 Rev3 200 fork has a different part number than the 250. I have long suspected that it is a softer spring. Could the new 125s have softer springs? Beta may know. You could compare the rear shock springs to a 125 to see if they are different. A suspension shop, like racetech, may also be able to provide a spring by looking at the originals even if they can not look it up by make and model.

Has anyone come up with a chain guard mod to keep the chain from sawing through boots?

Did you bleed out and refill the cartridge per the owners manual? It is what lineaway is referring to. It is not that hard to forget if you have not done it lately.

I see a manual and parts list here. There should be an alternating number of steel and fiber plates. Interesting question on weather the piston could pop out of the slave cylinder if not retained by the clutch. https://www.overlandtrail.biz/Montesa Parts Books.htm

Where is your focal point when doing a zap? I noticed that I'm getting over a good sized log off the ground fairly easily so am likely getting some lift there. There is a little hill a couple of feet behind the log and I am focusing on getting the front wheel on top of the hill rather than stuffing it into the hill. The focus is the angle of the bike and destination. The undercut areas I have been trying to zap don't really have anything behind them to focus on. I'm just focused on the edge of the step and using my legs. Mostly, I end up hitting the back of the bash plate (which is right under my legs) on the edge I'm concerned that I'm doing what someone recently told me was an MX saying, "look down, fall down.....instead of.....look forward, go forward".

You need to pull the flywheel so need the appropriate puller. Then it is just a couple of screws to remove the plate...pretty easy. Instructions are in the link. https://shop.betausa.com/p/evo-4t-oil-pump-upgrade-kit-09?pp=12

I bought a 2016 300 4t last year and noticed that American Beta sold an oil pump upgrade kit to decrease engine braking. I believe it was the same as the 2018 models so I bought one. I got used to the engine braking before installing so this past year it just sat in a cabinet. Recently, I have been going back and forth the between the 4T and a 2T and the engine braking was the most challenging part of transition so I finally installed the upgrade. It is just a slightly wider (3/16" maybe) pump module. It makes a significant difference. I actually forgot about the install for about 1/2 of the first ride back on the 4T and did not notice braking so it did the trick.

"starter motor and then switched to generate power" 1970 Yamaha AT1 125 had that

I was concerned that it may not be strong enough for 120 NM but it would explain why it has the locking bolt. Thanks

How do you hold the flywheel when tightening the retaining nut on a Beta 4T? (post 2014 2Ts may be the same) There are no threads to interface with like the older 2Ts. I bought a Tusk tool for this purpose but it is too small to fit the flywheel. I have a rubber strap wrench but it can not get a good bite.

Except for turning, I don't use the clutch much. Do you have any suggestions on developing that skill? Do you try to rev and dump or hold high rpms and feed?

I checked the reeds and I actually did not have the boyesens installed. I installed them and fully advanced the timing. There is a noticeable improvement. I have a 26mm OKO and wonder if it could improve response over the Keihin. It is interesting what this site says about Keihins on 125s. https://trialendurodirect.com/product/gas-gas-pro-performance-kits-ppk5/ The Keihin carburetors make a BIG difference to all GG Pro models. The standard 26mm Dellorto carbs are great for production because they carburate perfectly and rarely change whatever the conditions. The Keihin carbs are 28mm so that’s 2mm bigger than the dellorto which increases top end power, this is why all the top riders use them. Also because of the 2mm bigger bore they make the bottom end power very smooth and clean. The carburation is a little more tricky to set up and can vary in different conditions but the Keihin carb we supply should be spot on for all 250/280 and 300 Pro models. Only maybe a slide change is necessary. Fitting the Keihin carb to a 125cc will improve the top end power alot but you lose quite alot of bottom end which is maybe not a good thing for a 125. It depends on ability of rider and conditions used.

I have a 2008 Rev3 200 and the response is quite soft. I ran it with a 250 top end for a while and it did have more power but the response was still soft. It has the fast throttle and Keihin carb. Everything is in good shape and overall it runs good. It does have the Boyesen dual stage reeds. Could a reed change make a significant improvement in response? There is no add on flywheel weight. I have thought about shaving weight off of the flywheel but am concerned about making an expensive paperweight. I recently had a 2016 Beta 125 apart. It has a little tiny flywheel and impressive response for a 125.

You should find pictures on the web of what is inside. I cut a hole in a beta mid pipe and the steel wool packing was still in place. It was just caked with black goo and not easy to pull out. I repacked with steel wool and used some super soft aluminium plate to cover the hole. Silicone and rivets held it in place. I don't remember the allow you it formed as easily as aluminium foil. If you have good AL welding skills, a bigger hole would make it much easier

I agree with Tony27. I have come to the conclusion that the sweet off idle power of a new bike is totally due to a clean exhaust. I replaced the exhaust on an 02 Sherco and immediately got that new bike response....... for a while.

If you need to keep it from turning this will help. https://www.amazon.com/Motion-Pro-08-0427-Gear-Jammer/dp/B001AVS60O I have no experience with a 2004 but other years are all right hand threads.

Are you losing oil from the transmission? 2T oil build up in the exhaust will catch fire when the exhaust really heats up running under load. It also smells different from normal exhaust smell, sort of like a barbecue. If you just ride sections and then one day go off on a long hill climb, lots of smoke is expected.

konrad Thanks for that picture of how dimple. Can you share details on diameter and depth? Do you use a CNC or are you super patient?

Thanks for the reply. Do you know which model of the PHDS clamps you used? It looks like there are 2. It looks like the 790 fits with bolts coming up from the bottom but I don't know if the picture is correct. I would need something with bolts coming down from the top. https://www.ebay.com/p/KTM-Powerparts-PHDS-Progressive-Handlebar-Dampening-System-Supports-79001939500/735415457?iid=322420539044&chn=ps KTM PowerParts PHDS Handlebar Mounts79001939500 KTM PowerParts PHDS Handlebar MountsSXS.07.125.200

Has anyone bought or made cushioned or rubber mount handle bar risers for trials? I have the Beta Factory fork clamps so do have removable risers. I'm already running Jitsie bars which flex more than the OEM Beta bars. The KTM PHDS mounts certainly look like they would fit but the official email response was "no". I also would not know what model to order. https://www.motosport.com/ktm-powerparts-phds-handlebar-mounts Mako 360 is another option but I have not gotten a response from them. https://xcgear.com/mako-360/ Flexbars look like they move in just one plane so when pushed forward trials style probably would not help much. https://www.fasstco.com/ I also have a rev 3 with cast in clamps but don't know how you could do those without changing the top clamp.

I recently rode a TY175 with the B&J full engine mods. I don't know what all of the mods are but performance was extremely impressive. More power everywhere, much better response yet still silky smooth and pulls to extremely low rpms. I have ridden a TY with modified frame and another that was ported but they seemed at most a little different from stock. This was a whole different animal.

Like he said. I believe they are the US experts on this.

It seems to be the accepted method for Honda tin can cranks.

I have run that chain on a Rev3 and the narrow RK on a Sherco and Evo. The RK was slightly narrower, about 0.015". Sherco had plenty of room. The Rev3 and Evo were quite tight and I had to run the master link backwards for extra brake pedal clearance. They basically last forever, require little lubrication and don't need regular adjustment. Since he chain does not wear, sprockets seem to last forever also. They will saw their own clearance in the chain guide but V Mar makes a wider one specifically for O ring chains. http://www.vmar.com/chain-guide.html

Someone suggested I could use a chop saw to cut the big end pin to get it apart. Once the rod is off, it should not be difficult to support and press out what is left of the pin. Looking ahead, what happens if I press the crank too tightly together. Is there a way to correct or would I be back to the same problem but now have a big paperweight? It is for a friends bike and I'm not finding a local shop that does these.