mcman56

jacob429 I like the platform in your video. What size lumber did you use? Are the posts 6 x 6?

Beta 200 is a small bore 250 so just add 250 top end.

Sometimes I can get over this obstacle without smacking the foot peg mounts and kick stand bracket but mostly they hit. There is no rear wheel lift. What am I doing wrong? (I think it is everything but everything is hard to work on.) The one time you don't hear the hit, the front tire deforms a little so impact does help. How do you safely impact a sharp obstacle like that. Do you need to come down on it rather than hit the face or....?

lineaway - are you saying these will fit my 2016 beta with grimeca calipers? I thought ajp morphed into bractec

I recently changed from a Beta 300 2T to a Beta 300 4T and really like the change. It took me a while to get used to it but it takes me time to get used to any new bike. My riding skills are probably average. At my level it is still about doing things with throttle more than clutch. The 4t is slightly heavier but I can't say that it affects anything. The 4t has more engine braking but I can't say that it is a pro or a con. Mine is a 2016 and I bought the oil pump upgrade that is said to reduce engine braking but after getting used to it, I think I actually like the engine braking so have not installed. Pros It is very very quiet The 4t has more off idle power in that initial blip. This is good in coming right up to a large log. The 4t has less power at higher revs so you can be less precise with the throttle. It feels kind of fluffy. The 2t 300 produced a lot of power once wound up which could get away from you and was really no use to an average rider like me anyway. The 4t power comes on softer, more like a push than a hit. I find it less tiring to ride and it beats me up less so I am riding more. I think everything happens a little slower so I'm also in better control The 4t is very easy to kick. It takes a long slow kick with not much force. It gets better traction and seems able to regain traction easier if you do start to slip. No mixing of oil or cleaning of oily exhausts. It is hard to explain but it is more fun to ride, like a Reflex. Maybe it is the quiet smooth power. Cons That strong power on the initial blip tends to push the front end when doing full lock turns. To compensate, I changed my style to hold throttle steady and just use clutch in those situations. Full lock turns do seem a little harder. It could be a higher center of gravity due to the taller engine or maybe the geometry is a little different. The clutch is probably a little less progressive. It only has 5 gears so feels like it is missing 6th. For trials it is fine but if you want to do high speed road it could be a limitation. The gears are nicely spaced, not like the old Shercos that seemed to be missing 4th gear. Occasionally, after being dropped or stalled in some odd manner, it can take a number of kicks to get it going. It has 3 oil filters. One is changed out and two are cleaned. It is actually quite easy and quick to do. The carb is much more difficult to get out. Instead of a 5 or 10 minute jet change, it is probably more like a 45 minute or hour change....still not horrible. Valve adjustments are a lot of work. You come very close to pulling the engine to get it to rotate down and get access. The recommended interval is 60 hours so it does not have to be done often.

Message sent but does anyone know how to allow PMs. I looked at my profile but don’t see any settings for that

300s tend to be more slow reving than 250s so are stronger but a bit slower on response so can be easier to ride. However, if the throttle gets away from you and you end up at higher rpms they put out a lot of power that could get you in trouble. So, I think the answer depends on your throttle control.

I pulled out the parts. The smallest was thin and 1.3" ID. That must be the one I remember. The tapered part fits in the pipe. See picture. Send me a PM with your address, I can should be able to mail it. I have no use for it now.

I just looked it up. The outside of the spacer was shaped just like the exhaust flange with the two holes. The ID was 1.42" but I don't remember where that came from, probably some percent of the unrestricted area. It was 1/4" thick aluminum. I'll look for the actual part.

Front and back lighting wires simply unplug but the front plug is a bit difficult. If it is like the 2T, the ignition advance (sunshine/ mud) simply unplugs also. To go further seems to require cutting the harness.

I spent quite a bit of time experimenting with a 250 Rev3. (It is surprising what some people will do for entertainment.) - Instead of welding a washer in the inlet of the exhaust pipe, I made a spacer with smaller ID that fit between cylinder and pipe so it was removable. The pipe still cleared the fender but did not slide into the muffler quite so far. It softened the power quite a bit but also made it bog proof. You could use large amounts of throttle at low RPM and it would just chug along. If you are interested I may still have this spacer. I don't remember if I changed jetting. - In the US, Betas come without flywheel weights so adding one would soften power. - I made a carb spacer with small boost bottle. If you run the Mikuni manifold with a Keihin carb, you pick up an extra 1/2" to insert a spacer with port for boost bottle. IIRC this produced the same bog proof low end chug power but did not soften the overall power much. - A 26 mm OKO carb ran the same as a 28 mm Keihin but the response was just a tiny bit softer. - The expensive option is a 200 top end. The Beta 200 is a small bore 250 instead of a big bore 125 like most other brands. - Thicker base gaskets raise the ports to push the power band up in the rpm range. This would soften the low rpm power where most trials riding is done. It also drops the compression so would be easier to start. The 300 super Smooth runs low compression and is surprisingly easy to kick for a 300.

Water in gas can cause weird intermittent lean issues and be difficult to get out of system. I once pulled a carb and found a drop of water stuck in the main jet. Still, I can't see how that would cause a backfire.

Beta 4t engine maintenance schedule is based on hours so it is very useful.

Thanks for the input. I have heard that dealers do not like to sell identical bikes to two friends because one will always be slower than the other and they get complaints. I did not mean to imply that I put a lot of pressure on the tensioner. The only thing I did different was rotate the engine. The manual does not include a rotation. Assuming there are tight and loose places on the chain like a rear wheel chain, static adjustment would be random. With rotation it may adjust at the loosest point.

I put in a new tensioner today. First it was noisier so I manually pressed on the plunger while rotating the engine a few times. I reinstalled the spring and let it warm up. I think it is OK but as you listen to noises in an engine you can start to hear (imagine?) all sorts of things and I don't have another to listen to.. I made another video with the microphone not as close and out of an echo area. That specific noise is still there but it seems more in line with the other noises. Even when it was louder it went away or blended in as the rpms were bought ut to mid range. The tensioner is a ratchet design and tightens in steps. It seems logical it would get noisier as the chain wears but then quieter as the chain loosened enough for the tensioner to get out one more tooth. That could explain the difference between two bikes. The video is kind of vague because all you need to to to make it sound bad is turn up the volume.

Clearances were spot on. I rotated and looked at all parts of cam chain and it looked ok so I’m down to suspecting the cam chain tensioner. I hear the tap/ sound at idle but when I bring rpms up slowly to mid range, the sound is less noticeable or goes away.

I appreciate all of the input. I did notice it oddly hard to kick over at least once. I pulled the valve cover and see nothing obvious. The decompressor spring does not look broken and the decompressor is free to rotate. Surface finish of the decompressor shaft is not that great and looks like it was worked on with a file. If it was stuck, I guess it is possible it got unstuck during disassembly. The spring force is very very weak but it is a tiny spring. Locked in the TDC position, it feels like the weight of the lever looking part provides the force for returning. I can't rotate the cam so assume that means the cam chain is tight. Looking down from the top I can see red guides are there but no detail. Cam sprocket feels bolted tight to gear. Rocker arms have some end play but otherwise feel tight. Rollers that run on cam feel OK as does the little pieces that meet the valve stems. I did not check clearances before pulling the valve cover but, by feel, nothing was grossly loose. There were a couple of very tiny flakes on the magnetic drain plug. Oil looked good. Nothing was in the two plastic oil filters. Any other suggestions? I'll look again but all I can think of is to loctite the gear to sprocket bolts, set the clearances and see what it sounds like before going deeper.

I pulled the tensioner out. Teeth look ok and spring has enough tension to push out the plunger when off the bike. When it was out, I tried pushing on the red guide. It felt solid but I don’t know what it should feel like. It does sound much like a klx250 with bad tensioner I heard recently

I have a 2016 300 4T with maybe 75 hours on it, almost 35 since valve adjustment. It runs fine and starts easy. On the last few rides, I noticed that the top end seems to be noisier than before. Nothing sounds horrible but there is some "clitter clatter". Probing the head area with a mechanics stethoscope, it seems a little louder at the cam chain tensioner. Is this normal? See the video. It does seem to sound worse in the video than in person. The deep sound that comes and goes is it quieting down a little when pulling in the clutch. The engine was cold but I think it sounds the same hot. If not normal, any ideas? https://youtu.be/gk9x64aulWQ

I go up to 100 psi with tire lube

It sounds like the throttle is barely opening. Could it be too much play or some kind of binding. You could pull the carb boot off to verify full opening or even pull the slide out to verify. Other issues should have different symptoms.

I may have had it easy. It was a 6 volt points controlled ignition that was already 25 years old at the time. The coil had 2 leads that fired two plugs at the same time. Modern ignitions must have a lot more zap.

Comedy Central - I was once riding a V twin motorcycle with no insulation at the spark plug cap while wearing shorts. I lost my balance at a stop, planted my foot on the ground and the bike laid against my leg. Continuous high voltage shocks zapped my leg while I fought to regain balance and get the bike off of my leg. So, I can say from experience you would know. (This was prior to Youtube.)

I had a similar issue with a fantic 80. I had to use a hydraulic press to press the axle out. It took a surprising amount of force but did not damage anything. They are called shop presses here but seem like one of those things that may have another name elsewhere. Something like this. https://www.harborfreight.com/20-ton-h-frame-industrial-heavy-duty-floor-shop-press-60603.html

My 4t usually has a very steady idle but sometimes it will step down about 200 rpm and stay there. The idle does not wander like a lean 2t. It may not do it for a couple of rides and then do it consistently. Otherwise runs fine. I fiddle with the mixture screw and it does not seem to help. I do ride at different temperatures and when it started today, it was maybe 20 degrees cooler than it has been. 25 pilot, screw 2 turns out, needle one step rich from mid, 125 main. The plug is black but does anyone get a tan plug on any beta? Beta seems to run cold plugs and I never got a tan plug on a Beta 2T either. Can a blackish plug in itself cause idling issues?