mcman56

The REV3 rear disc is 5 mm bigger in diameter. I tried comparing the REV3 pedal to the evo pedal. The REV3 does look longer but there are so many curves it i shard to put a number on it. I believe other brands like Gas Gas actually have smaller discs

Are there any new learnings to improve the evo rear brake? I had a 14 Factory with weak rear brake and tried everything, all kinds of pads, new disc, replace master cylinder and caliper with latest (2017 or 18?) Still it remained much the same. It did not feel spongy, just weak. If you stomp on it, it will stop but it is not easy to finesse in technical situations. Now I have a 2016 evo that is the same. Others have had a similar experience. My rev3 rear brake was vastly superior. I have ridden 2019 and maybe 2018 models that have quite nice rear brake feel but when I look at all of the hardware, it looks the same. ?????

Standard factory recommendations seem to be 1 to 1.5mm

I find pulling with vacuum from the bleeder nipple to be the most effective. When changing fluid you can just keep it always full so there is no air to bleed. I also use the push with syringe method and the pump and release method. Sometimes I think the different methods help get bubbles out of different places when it does not go well. Still, bleeding hydraulics on a trials bike, particularly starting with a dry rear caliper, can be a very frustrating job. In addition to methods and techniques, I often feel that there is some sort of higher power that requires a certain level of emotional suffering from the mechanic before allowing those last few bubbles to exit.

Starts and runs fine until riding to sections then smokes excessively If the exhaust is full of oil, it may catch fire and smoke excessively when riding to sections. It will also run funny and have a weird smell, sort of like a rancid barbecue. You could be burning off the oil that built up from the bad seals. There are some posts on here about cleaning out the exhaust. Another way is just to run it hard and keep a lot of heat in the exhaust until it burns out. This could be a long ride at the speed it starts smoking on the way to sections or a nice long hill climb. Repeat until it stops smoking.

What drugs could help trials riding?

Keihin PWK does not come in 26mm

Personally, I have found the Keihin carb particularly insensitive when trying to adjust by the "fastest idle" method. In fact, one day I was riding with a rider on a new 250 Evo and when he went to adjust the idle mixture screw found that it had fallen out. The bike still ran OK. I try and use the "adjust and try" method. Not that I would recommend it but a 26 mm OKO would be a simple swap as it is the same size and uses the same cable.

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.