mcman56

Just choosing one model on that web site is shows "4x galvanically isolated analog inputs (range from 0V to 10V)" . I'm guessing it means that a voltage is sent from the throttle. I have a friend whose throttle hand twitches like someone who has Parkinson's. Somehow he manages to ride a trials bike and has just ordered one of the EM bikes. It seems to me that an electronic signal could be averaged over time to filter out his twitch. This would certainly help him. Has anyone tried anything like that? The goal is just to be able to continue to ride.

Are there any technical specs on how the EM motor is controlled? Is the throttle just and adjustable resistor? Does that just go to some kind of standard industrial motor controller with programmable parameters? Or is there some type of computer in there as well like similar to a fly by wire gas powered street bike?

I have a fresh TL250 with stock gearing and it will lift the front wheel with the throttle only.

I now have a TL250 up and running. It works much better than expected except on tight turns. Has anyone tried longer shocks to help turning? What length?

Troubleshooting further, I did notice a little black smoke at the stumble spot so it was in fact rich. Increasing the slide cut away from 2.5 mm to 3.5 mm like the OEM TL250 carb has eliminated the issue. When looking on line how to cut the slide, I found nothing so will pass on how I did it. See pics. If you are good at doing things by eye, it would be much simpler to use a file.

Did you have to do any tuning to get them to work correctly? I now have my TL250 running with a china copy but it stumbles and wants to stall just off of idle. It runs fine above that rpm and at idle. It is very throttle position specific and stumbles just as the slide lifts. I'm guessing it is throttle slide cut away. However, I do have just the slide from the OEM slide and the OEM has a larger cut away than the copy. If this is the issue, it seems opposite from what I would expect. The chamfering is a little different so that may explain. I'm not sure how to proceed.

I have not heard of these. What exactly are they?

It is not easy to use standard bent feeler gauges for valve clearance inspection and I would think a 90 degree bend would work better. Has anyone found 90 degree gauges in the correct size? I found some sets used for big diesel engines but the smallest is 0.008" and they are needed down to 0.004" (0.1 mm). There are some straight brass gauges. Do they bend better than stainless steel?

You need to remove the carb. The packaging is very tight and there are a number of tubes connected.

Very interesting modification. Over the years, I have heard of removing springs, spacing out spring mounting bolts and using thinner plates as a way to reduce drag but I fail to see the logic. I can see that all of those things reduce the amount of spring force on the clutch and can make it easier to pull in. However, as stated, isn't it the gap that allows the plates to separate. Hydraulic fluid can be considered incompressible or nearly so so why would spring force affect drag with clutch in? Is the theory that the outer clutch cover held by the springs flexes and will flex less with less spring force so there will be more gap? Or maybe that the clutch line expands and will expand less with less spring force? Has anyone tried to measure this?

LewisportUSA used to sell them. Adding base gaskets is another option.

Lots of trials bikes do that. One friend would pull in the clutch, put it in gear and rock back and forth with the engine off to break loose. I find it easiest to start the engine and put in gear with a little open space in front, clutch in. 20 seconds of riding around blipping the throttle with the clutch in breaks is loose. Do clutches still stick with dimpled steel plates? I heard that some year Beta's came with dimpled plates.

I used one from a 1990 XR100 on a TLR200. It was a little shorter and worked better with less flex.

"following through" mentally can be important. When I started, I always felt a bit out of control on the back side of logs. My technique even included an odd triple blip for some unknown reason. Finally, I realized that I was just thinking about getting over the log with no follow through of where to go next. I altered my thought pattern to include placing the wheel on the ground on the far side of the log and results improved quickly.

This is the float valve in the carb I have. It is marked 270 on the brass part.

I happen to have one of those carbs that came off a good running 315, maybe a 2000. It has a 45 slide, 46 pilot and 114 main. I don't think that second slow jet is there. The manual says float height is 18.5 mm. A quick look on line suggests that 315s came with a 46 pilot so a 33 would make it quite lean. I would try a a 46 pilot or at least something bigger than what you have. I don't know how sensitive the bike would be to slide changes but that should just affect the transition off of idle as the slide lifts. Stock Jetting A manual is here. http://montesatrials.com.au/store/wp-content/uploads/bsk-pdf-manager/Montesa_315R_02_2002_2.pdf

It sounds lean. Have you tried adjusting the idle mixture screw to make it richer? I believe turning the screw clockwise makes the mixture richer on that bike. Clean the carb again. Check float height and take a good look at the idle circuit and pilot jet again.

I found it, thanks. There are two springs and a couple of sealing spots in the cap. If things get out of shape, I wonder if it can sort of become a pump. I cleaned and reassembled and will see what happens.

Are you saying fuel normally comes up out the tube? I can be sitting on the bike not moving and watch it bubbling. What would push the fuel up? For something to flow out it, there would have to be expansion or some kind of flow in. I looked up CSP caps and only see them for 2018+. They do not include a vent line. I believe 2018+ has a vent line connected to the tank directly. Mine is a 2016 and would need a vent.

During the last few rides on my 2016 Beta 300 4t, I started smelling fuel. I have a clear tank vent line and I can actually see gas bubbling up the line. A 1/4" or so of air will be followed by a 1/4" of fuel and so on. It sort of slowly oozes out the top of the vent line. A long time ago I put on a long vent line because fuel will spill when pointing sharply down hill and ran this a long time before this issue. See picture. The fuel line is not too near the exhaust. The bike is not overheating and the tank did not feel particularly warm when I put my hand on it. The tank does not have to be full for it to happen. It does it with and without the vent fitting on the end and with the tube facing up and the tube facing down. The hot start line was touching or just about touching the exhaust. I have corrected but not tested and don't see how that could create this issue anyway. The bike runs well but can somethings be finicky to start. Are there any ideas on this?

You are rarely in high traction situations in trials so I don't find the TY brakes to be an issue. The TY is also not that heavy at around 175 lbs. The Honda 4t is listed at 170 lbs so not much difference at all. As an amusing example... I had been just riding my TY for a while and commonly riding over a log about 12" diameter with the top maybe 18" off the ground. One day I went to the same exact place on a 280 Beta. I lifted the front wheel and anticipated the front wheel hitting the log so I could apply the second blip but the back wheel was instantly on top so I was over the log before I knew what happened.

I believe the answer is related to your talent level and type of stuff you ride. I'm an average 65 year old with a modern Beta and a TY175. On any modern bike, I am constantly on all of the controls; throttle, front brake, clutch and back brake. My TY is geared quite low so I get some engine braking and can mostly ride with just the throttle. I find it much much easier to manage one input vs. four. (For a talented rider this probably does not matter.) Brakes are weak so when you do use them you don't have to worry about stalling the engine with the back brake or easily washing out the front wheel with the front brake. Power is soft so you don't have to worry much about using too much and things happen slower so reflexes do not have to be so sharp. (This may be the definition of forgiving.) It is short so some people say they can turn tighter on a TY175 than they can on a modern bike. Overall, it can be much easier to ride in many moderate sections. However, there are a few situations where there is no comparison. Due to lack of suspension, the TY feels like the ball in a pin ball machine in anything like a rocky creek bed. The lack of abrupt power makes it difficult or impossible to get up bigger obstacles if there is no run at it. (Riders skilled with firing the clutch would not have this issue,) The third thing I notice is that the TY clutch out riding style sort of commits you to a certain line in a tight turn. If that line does not work out, there is a dab. On a modern bike, I can pull in the clutch to regroup and make corrections mid turn.

I had a 2014 Evo 300 2t Factory and now have a 2016 Evo 300 4t. They have very different power curves. The 2t was quite soft on the bottom with a grunty type of power that was very easy to modulate. However, at higher rpms it became quite powerful. If the throttle ever "gets away from you", it would not be a good beginner bike. My 4t is not so soft right off the bottom (particularly just as you let the clutch out). It is really only noticeable on full lock turns. However, the rest of the power curve is very smooth, almost feeling kind of fluffy. You can be much less precise with the the throttle from mid range on up. Other brands are likely different. If you are a lightweight, older Beta 300s required a pretty firm kick to start them. I have read that the newer ones are easier to kick. Timdog Does the Amal 80/200 smooth out that initial cracking open of the throttle? Does it use the same cable? I would like to smooth out that little part but would not want a slower throttle anywhere else or have to twist it farther. I have read that newer 4ts come with a different/ smoother throttle but don't know how they compare. I wonder if that initial little surge is throttle related or more related to inertia of the slide when it first lifts. Do the Hondas so that? I prefer a slow idle around 1300 rpms and suspect it would not be noticeable with a higher idle.

The evo 300 4t with standard muffler is the quietest trials bike I have seen by far, even quieter than a Reflex. I was warming up mine the other day. It was on the other side of a sliding glass door and I had to listen very carefully to tell it was running. I have heard that other mufflers give it much more power and much more noise. I do think the evo 2t clutch is a little more progressive than the 4t clutch but not a huge difference. The 4t is vey easy to kick over.

https://betausa.com/content/SUPPORT_PDF's/2008 Rev 125-270 2 stroke owners manual.pdf Be sure to drain the cartridge. After filling, be sure to then pump the air out of the cartridge.