mcman56

Can someone explain why Betas neeed a hotter plug in the UK? Temperatures are similar in other parts of the world. UK bikes come with flywheel weights but I think that would be more load on the engine and actually increase temperature slightly.

I posted that original picture. This was a street bike so I assume it twisted during some sort of crash. When I assembled the bike with a 428 heavy duty chain, the chain was touching the inner primary cover. I needed to do something and was able to bend it back. I had a steel motorcycle carrier that fit into a 2" trailer hitch. A bike would ride in a long piece of steel channel about 5" wide across the back of the vehicle. It was a bolt together so that I could assemble it with the flat side of the channel facing up. I welded tabs on the flat side that would mate to the footpeg mounts and lower motor mounts on the frame. With the hitch slid into the carrier on the truck and the frame bolted in place, it was pretty securely mounted. I then made a pin that was a close fit in the swingarm pivot and put it in the end of a long piece of 1 1/2" pipe, maybe 8 feet long. This became the lever arm to twist it back. I had to use heat from a propane torch to get it to move but was able to move it into visual alignment. I did get hear one "tink" in the process but could not find a crack or any other defect so am not sure exactly what moved. I made a close inspection after riding in multiple rocky trials and it continued to look good. When placed on a flat surface, I could see that the swingarm was also bent. It was pretty easy to straighten so I don't remember the details. I think I mounted in a vise and used a lever or maybe hammer. I found a picture.

I have an O ring chain on a rev3. I did a little bending and a little sanding plus had to run the master link clip on the inside.

I'm considering a new Evo 4T but so far have not gotten to try one. I see that it is a 5 speed and recently read somthing about it having a big gap between a couple of the gears. Can anyone comment on that? Are the ratios listed somwhere? Does it make it a poor trail bike (vs trial bike)? The 6 speed Beta's and Gas Gas seem to have a near perfect gear for everything. I did have an 02 Sherco that had a big gap between 3rd adn 4th (I think) It was annoying on a trail ride. Is the Beta 4T the same?

I had a 2002 Sherco 290 and it had a big gap in the gears. I think it was between 3rd and 4th. That made it a poor trail bike for me. Do the new Beta 4T still have the same transmission?

Is the weight the round disk behind the gear in the last picture? Is it as heavy as the bolt on flywheel weight? http://www.ebay.com/itm/Beta-Rev-3-250-Engine-Bottom-End-Crankcase-Gearbox-Breaking-Trials-/261334134831?ssPageName=ADME:B:SS:US:1123

Your local trials club (PITS) uses "no stop" rules for Saturday events. AHRMA events are also run that way.

I have spent time looking at the parts lists. From what I can tell, the difference between the 250 rod and 200 rod is that the 200 rod comes with the bushing installed. It looks to be the same case with the complete crank assembly. As far as flywheel weights, I beleive UK sold bikes are delivered with the weights installed but US sold bikes come without them (less mud). It also looks like the ignition changed somtime on the Rev3s and the hole to hole difference on the weights have to match the year of the bike. My 2008 has an ignition made in someplace like Slovenia. One thing I do not understand is that I have seen flywheel kits for sale that include a spacer for the ignition cover to make space for the weight. My 2008 has plenty of space without any spacer. Does anyone know why that is? Maybe that is for the "other" brand of ignition. IMO appreciation of a flywheel weight is a personal preference thing. It slows down engine response and makes the bike much more contollable in slick and slow conditions. This can make abruipt steps more challenging. With a weight, there is also a lot more run on when the throttle is closed. I like that run on when going up short walls. You can approach the wall, hit the throttle for power, chop the throttle and then let the weight pull you up the wall with no need to use throttle. However, I have a ridding buddy that rides the same things as me and he hated a weight. That run on gave him an out of control feeling. After that long winded message, I realized that I did not answer the question. I believe the flywheel weight is item 23 on page 6. It is just a flat plate that bolts on the outside of the flywheel so it is very easy to install and remove. That page also shows the spacer, item 26. It looks like this: http://shop.americanbeta.com/p/flywheel-weight-kit

Can someone tell me how to remove the liner from an Airoh helmet. The side "ear" pieces snap out. The rear of the main liner also snaps out but how do you get the front of the main liner loose? Are there instructions somewhere?

I get a similar but slightly different number. The CR is BDC volume/ TDC volume. Head volume is included in the BDC volume so the head volume would be more like 26 cc. The new condition would be 308/ 38 or 8.1 CR. I just tried to paste in somes spread sheet cells but the format got lost. I did run a 1/16" (1.5 mm) head spacer on a 250 Techno. It ran fine. The only unique feature was that it would tolerate being pushed down to very low rpms with a heavy load.

Can you post a picture of what the head spacers look like before they are installed? I would be interested in seeing what a Rev 3 head spacer looks like. The really low published CR may be from a Japanese bike. They tended to calculate an "effective" compression ratio. For this calculation, the stroke was from when the exhaust port was closed by the piston to TDC. This produces a smaller number but tries to give importance to port timing.

I made a 1/16" thick head spacer for a 250 techno that my 4'10" 100 lb daughter was trying to start. It used o-rings instead of steel gaskets so was a bit different. It sealed with o-rings on one side and just RTV on the other. It ran OK and still does 8 or so years later but with fresh piston and rings was still too hard for her to start. With a mill and turntable, the spacer was not too hard to make. The Rev 3 steel gasket is also a water flow restriction so that would have to be considered. The Rev 3 200 is a small bore 250/ 270 and not a big bore 125. It uses a bushing to reduce the small end rod diameter but all else...carb, exhaust is the same. I converted a 2008 200 to a 250 by installing the 250 top end. I have been planning to put the low hours 200 top end on ebay but have not gotten around to it. If you are interested send me a PM. I also think there is an older 200 cylinder on Uk ebay right now. The older ones used a steel sleeve but the 2008 is all aluminium. I don't know when Beta made that change.

They do transfer less shock to your hands and forearms. Like when you slam the skid plate on a rock or solid log.......a little less shock is tranferred to your hands. That is the reason I put them on.

I put fat bars on a 02 Sherco. Using Pro Taper Suzuki Factory/ KtM bars and adaptors, bar position was almost exactly the same. The extra flex was easier on hands and forearms.

I only pulled off one side of the cases from the crank. I had to make a pull fixture to "push" the crank out of the case half. It did not go easily and wanted to tilt and jam so took a bit of time.

It was a tapered shaft fit so I expected it to be difficult like a flywheel. However, it came apart very easily...surprisingly easy. I just tapped it with a light brass hammer and then pried up with screw drivers. (being careful not to damage the gasket surface) This was a 2008 that started as a 200.

A little water can do this and be very hard to see or find in the system. I have seen a little drop stuck in a pilot jet. On one bike I drained and air dryed the entire system but still had the problem. Finally a can of dry gas cleared the water. Dry gas has differferent names but is basically alcohol that would absorb the water and help pass it through the system. However, if you have ethanol in your gas it would probably be self clearing.

The 2008 Rev 3 parts book shows a spacer between the intake manifold and reed valve for the 250/ 270. It does not show one for the 200. Do all 250/ 270s have the spacer? How thick is it? Has anyone tried removing it?

The Evo manual shows a pusher/ puller for removing the crank. I was able to make a plate that mounts to the cases. I bolted an existing puller to the plate so it was not that much work. FWIW, the Evo manual is almost an exact match to a 2008 Rev 3. http://www.lewisportusa.com/manuals/beta/Trials%20service%20manuals/2010-2011_evo2t.pdf

The crank gear has a tapered ID and is attached by a bolt to a tapered shaft. There are no location features like a Woodruff Key. This little gizmo worked great. Even at 120 NM, the tool looked fine when done. http://www.motionpro.com/motorcycle/partno/08-0427/

When you say a good pop, do you mean on throttle, idling along or when chopping throttle? I have not been on a 250 Rev 3 but an evo I rode did not have the pop. It had the ring ding ding. Could the pop be normal? I have heard other bikes do it a little. I suspect that manufacturers use older model parts on bikes that are not their top of the line...like the Beta 200. But, it does seem odd that the 200 crank would have more metal/ mass. I have been through all tuning variables I could think of; timing, jetting, compression, squish, etc.

This is a 2008 200cc model. After, installing an earlier model (03?) 250cc top end, there is an annoying POP POP POP POP in the exhaust when chopping the throttle. This is accompanied by some surging and the popping basically replaced the normal ring ding ding ding. Otherwise, it runs fine. After leak testing and adjusting all possible tuning variables, the pop remains the same. The bigger bore would raise the primary compression ratio so I thought that there may be stuffers that could be removed. There are no stuffers so I'm wondering if the 250 crank is different. Are there any suggestions?

Does anyone know if a 250 or 270 crank has more holes in it than this 200 crank? I was expecting stuffers but there are none.

I had not thought about locktite. The hex is way too small for an impact driver but about 5 minutes with a heat gun did the trick. thanks!

Are there any recommendations on removing the stop cam on a Rev3? This is the aluminium gizmo under the clutch cover and on the end of the shift drum. It is retained by what looks like a flat head screw but moderate force is not getting the screw to move.