mcman56

I already had some PB blaster on the threads overnight. With some heat form a MAP torch, they came out OK without a lot of fuss. I was surprised.

I bought a new chain and sprocket kit for for my TL250 but no spacer was available for the rear sprocket. I can make one but am seeing only two ways, neither of which is highly desirable. See picture 1. -If I mount spacer to hub and then sprocket to spacer, I will have to open up holes in the freshly anodized sprocket for nut clearance for the spacer to hub attachment. -IF I could find longer studs, I could use them and basically sandwich a spacer between sprocket and hub. However, I suspect that studs that have been in place for 1/2 century will not come out easily. What have others done? Pictures? The sprocket is supposed to be a TL125 sprocket but has an undercut on the back side. Does anyone know what that is for? Sprocket at required spacing https://ibb.co/tXpwXfJ Back side of sprocket https://ibb.co/FgMt0nQ

I don't remember the Techno but there was a CDI/ coil combo replacement for the 2008 Rev3. I bought one as a spare and still have it but have no idea if it would work on a techno. The 2008 Beta came with separate CDI and coil. https://www.hpi.be/item.php?item=CD13201

I'm not sure if this helps but I had a Techno and it was likely a 1997. I once put a timing light on it and got 6 degrees at idle, 20 at mid range and 25 to 30 at full scream. If the CDI advance stuck at full advance it may kick back. In contrast a 2008 Rev3 200 had 15 degrees BTDC at idle and revved up got 20 degrees I'm not an EE but from my understanding, an ignition with no designed in advance will give you about 5 degrees due to higher generated voltages at higher RPMs making things happen a little quicker.

Not really answering your question but I aren't all coils for CDIs similar? Could you use a pit bike coil? IIRC, there are inductive (battery powered) and capacitive discharge ignition coils and they have different resistance values. You could measure to compare. What brand is the stator?

Is there any kind of manual related to servicing the shock on a 2016 Evo 4t standard model? If not, are there any specifications for oil type, oil volume and gas pressure? I do see the remains of a sticker that probably said Sachs. I softened the fork valving and like the result so would like to soften the shock also.

Nice write up. Would this use the 60 volt DROK?

A friend has a 22 Epure and the battery status is stuck at 0%. The bike works and appears to charge OK. Is there a way to reset or calibrate? Does anyone know how this works? Is it a simple voltage measurement used to estimate % charge?

It turns out I was trying to push the rod out from the wrong location so it was not really stuck. I cleaned and polished the sliding parts. Steel plates were glass beaded and the friction plates replaced with Yamaha parts. Swapping spring locations while checking with an indicator got the plate to move out evenly within .05 mm. Clutch works great now. I suspect it was really the new friction plates that helped the most. I did polish the actuator but have never looked at another old one for comparison. I suspect that all 45 year old actuators look less than perfect.

My 2014 Factory model came with those. The parts list shows them in positions 2 & 4 of 6. There was something else different about the clutch too, maybe the hub. I could never figure out what the additional features were supposed to do. The clutch did not work any better or any worse than any other Beta clutch. plate https://trialworld.es/tienda-trial/en/clutch-trial/2668-beta-evo-factory-steel-clutch-disc.html

https://www.vmar.com/tripleclamp.html

I have had the bike for a couple of years but have no idea how old the friction plates are and am not sure what a "bad" friction plate looks like. What is the wrong oil? I have been using Dextron ATF but I think it is now called DEX/ MERC Clutch spring lengths are within 0.25 mm. I'll have to inspect plate movement when I get it back together. The basket has been filed but I'm planning to try cleaning up the fingers on a mill to ensure straightness. Friction Plate - https://ibb.co/fv3qJzk Hub - https://ibb.co/yhJrbdd

The sticking got so bad the bike would occasionally pull a wheelie when starting with clutch in.....even with a warm engine. I pulled it apart but nothing looks that bad. There is a little mark on the clutch actuator but I can barely feel it with a fingernail. I may be able to polish it out. Plates are not warped and specs in manual are met...if I can read the decimals in the manual copy properly. Steel plates had some minor corrosion in the past but had been sanded. Should that matter? The only odd thing was that I could not push the actuating rod out with a wire so resorted to 100 psi air. It looks a little dirty. Ball was in place. Pics Actuator https://ibb.co/60Q6Gs5 Hub https://ibb.co/74pXKdY Dimensions https://ibb.co/WtnFkN5 Plates & Rods https://ibb.co/pQTpTVd

I gave it away.

Are you talking about sticking when cold after the bike has sat for a while? That is common in many trials bikes. I have learned to live with it on some bikes. Start bike, pull in clutch and give bike a little roll forward while putting in gear. Ride bike forward with clutch in and blip throttle. It will break loose in 10 feet or so and not stick again until next cold start after sitting....if it is just a cold start issue.

Height is a problem. I'm 5'5" and the the top of the beta kicker is near hip height. It is difficult to get any weight above the kicker and I would assume really bad if you have a knee issue. I find Rev3 and Evo take about the same kick effort. The 4t kicks over very easily. At some point, I heard that Beta started putting a groove in the bore of the 300s to make them easier to kick. I did get a ride on a 300 super smooth and it was surprisingly easy to kick. I think it was a 2018...aluminium colored frame I think.

Beta's have a reputation as an easy starting bike. I have had 4. Have you cleaned the carb?

Do you think the old damping rod forks may be easier on hands...up until the speed they spike. See the graph 1/2 way down the page in this link comparing damping rods with cartridge forks. https://racetech.com/page/title/Emulators-How They Work The damping rod curve certainly looks easier on hands to me. I'll try riding my TL250 and see how that feels.

IIRC, there is a hole in the frame that takes a grommet similar to a grommet that protects wires going though sheet metal. That post on top slips up into the grommet. See item 12. I had a 14 model that did not line up well, was hard to get into place and tended to break the grommet over time so I can see why someone would use tie wraps. After a few replacements the grommet stopped breaking on me. Bolts go into rubber bottom mounts, See link. https://ibb.co/2KfTv3j

I have arthritis in both thumbs. The trapezium bone has been removed in one hand and pending in the other. Some knuckles are not in great shape either. Both hands and wrists are getting quite sore from riding and stay that way afterward. I would think modern suspension would be better but my Beta 4t is harder on my hands than my TY175. On the beta I'm constantly on the clutch and front brake plus ride bigger obstacles. (I did put thinner oil in the forks.) On the TY I'm mostly on throttle only and suspect the skinny forks flex around to help cushion things. I do try to minimize hand pressure when riding. I have thought of an electric bike because you don't need to use the clutch but I'm not sure if the clutch is really part of the problem. Has anyone found any tricks, accessories or mods to make trials easier on their hands? Are some bikes easier on hands? This question is from the perspective of being able to ride not from the perspective of being able to ride well.

Are there any documented gate trial rules? Are there variations? I have seen one type where the first footing means the rider has failed the section. This seems a bit harsh and would encourage very conservative riding.

I still need to pull it apart but have never looked at the cam. It looks like they are unavailable. Can they be refinished? Do you have any experience with different brands of friction plates? Yamaha, EBC and Vesrah are available in addition to non branded probably Chinese ones. Do you have any idea what kind of grooves can be put in the metal plates? Are there any pictures out there? It seems like they would encourage warping. IIRC, the OEM plates are dimpled.

As purchased, my TY175 clutch worked OK but had a some drag and was abrupt compared to a modern bike when released even with a lever arm extension. At some point in time there was a lot more drag and it became more abrupt. It would even stick when riding such that when you pull in the clutch and there was a delay before disengagement even when hot. I sanded the steel plates but I forgot which roughness of paper used. I filed the clutch baskets mostly flat but not totally flat. I also removed some burrs found on the ears of the fiber plates. All plates looked flat. It was improved and maybe similar to when I purchased the bike but after a small number of rides is back at its worst. Could this be the steel plates getting polished up again? I have a glass bead blaster. Could that be better? Any suggestions?

On the 2016 there is a connector right in front of the rear wheel. The first time I took it apart I found green connector pins and I live in a mostly dry climate.

On my 2016, there is a connector under the fender near the air box that connects the electronic petcock and the fan. If you are doing anything in that area it is easy to disturb that connector. It can look connected but is not. I have to be very careful to push it together firmly. I have had the petcock and fan not work in the past due to this situation.