mcman56

Does it have the same transmission ratios as the trials engine?

I did get one and install. It does feel more lively and seems to absorb more for a more cushioned ride.

Maybe here https://ricksmotorsportelectrics.com/l/aftermarket-stators?srsltid=AfmBOooPHVWzz3Ug93MZ2_SBhLpL4CSpiGre4s0rPjAvfj3MdIMHyP4V

Why do they rub? Do the springs have a smaller inside diameter? Is the plate just slightly thicker with the groove to center the springs.

Are HP and torque numbers available for the standard Beta 300 4t, maybe with rpm numbers? I have one of those too. In a tight section, the Montesa feels much more powerful so I need to use very little throttle. I thought it was overall more powerful. However, the other day I took it to some open trails with good size hills. There it feels similar to the Beta. I wonder if there is a real power difference or if the fuel injection just makes it more responsive.

Thanks for the clarification. I was installing some spacers to reduce spring preload. I planned to pop the plates out to see if it had dimpled plates but was surprised that the plates could not just slip out. It is sort of the reverse of every other bike clutch I have ever had apart. I learned something new.

I had the clutch cover off and am struggling to understand how the clutch actuator works. Every bike I remember controls the bike from the opposite side of the engine. A rod goes through and pushes the pressure plate out to create clearance and release the clutch. On this bike, the slave cylinder pushes in the opposite direction. So, is the movable pressure plate on the back side of the clutch pack when compared to other bikes? The parts list looks like that.

How much do these links raise the bike? Does it provide a softer ride? The H&D description is hard to interpret. I'm not a trick rider but would like something more compliant so easier on an old body. The Montesa rear suspension also feels quite dead compared to my Beta 4T. "uprates the soft rear end and aids the ability to 'trick' ride and hop around the rear end by providing an even more progressive shock."

The parts list shows one but I don't remember if mine has one. https://www.tytrials.com/trailandtrialsuk/cat_57217-Clutch.html

In addition to the diaphragm for the slide, the carb has a diaphragm with spring on the side. On a CV carb diagram for a different bike, I see something similar identified as a coasting enricher. I think I have also seen something called an anti backfire valve on other carb diagrams. Could that be the culprit? Is the purpose of such valves to prevent a pop? The bike runs well so I'm reluctant to change jetting. MK-BSR33-79-Detail-Sheet-copy.pdf

This is their rule book. https://www.ahrma.org/ahrma-handbook/ I'm no expert but the few AHRMA events I have seen even have a class that allows modern bikes so you should be able to find a class for anything. IIRC, otter frames are not legal for their pre 65 class. I have seen TY175s with extended swing-arms and lay down shocks competing but I don't think they meet the letter of the rules. Based on absolutely nothing, I wonder if no one is too picky about the rules unless you are going for a championship.

Plug color is a bit uneven but doesn't look too bad. It doesn't smoke. I am running much leaner than stock jetting. When I got it in 2018, it had the factory jetting of 27.5 pilot and 120 main but ran poorly. The advice was to go richer but when I went that way it was worse so I went the other way. It kept running better the leaner it got so I ended up with 17.5 and 115 which is much leaner than all recommendations. The engine is getting up near 300 run hours so I wonder if it has slightly less vacuum and is less tolerant of lean jetting.

I have a 2016 300 4T standard model. It has started to produce a little pop in the exhaust when closing the throttle from small to moderate openings. The pop is not loud but sort of echos in the exhaust. It starts, idles and runs well but has become cold blooded so needs to run for several minutes before it will take any throttle when cold started. I checked valve clearances and cleaned the carb with no affect. This is with California pump gas. Has anyone experienced this? I'm not sure if I should go up on the pilot size or raise the needle. Carb access is not great on this bike.

I was curious so looked at the manual. It looks like the minimum piston clearance for the 250 is 0.050 and the maximum is 0.080. What is the 0.100 "Assembly" number?

It definitely should do much better than that. Could someone have geared it way up?