mcman56

I sealed the exhaust and went up two sizes on the pilot jet yet the pop is still there. At 60 degrees F, it started without the choke but did sound lean until warm. Could it need to be richer?

I have heard that a solid bronze main bearings (plain bearing or bushing) transfers heat better than the OEM bushing. When I tore down my C15, I was surprised by the quality of the OEM bush. It was pretty bad. There was an outer steel housing with an inner bushing. The inner bush was not even a machined ring but had a split in it like it is just rolled in place. The inner bush looked to be plated with copper. I coppied the design in solid bronze. The bike is running but does not have many hours on it so I can't make statements about durability.

My fix only lasted until the next removal. After a little research, I found EZ Loc. They are large enough that the hole is fully cleaned up prior to tapping yet small enough to fit in the small mounting blocks on the frame. http://www.ezlok.com/Home/index.html

I will be interested in hearing how you make out with the pit bike ignition. I tried one of the pit bike inner rotor ignitions on a C15 but could barely get a pop out of it. They may vary in performance so you may be more lucky. To see what was going on, I set it up and ran it with a milling machine. For comparison, I also had a Honda XR50 and a Yamaha PW80 ignition. Both Japanese ignitions would fire a spark plug at lower rpms than the pit bike ignition. I put it on a fresh motor and just coil not get it spinning fast enough with the kicker. I tried to squeeze in the XR50 ignition but it just would not fit under the cover. It is surprisingly big for little 50 and would probably be too heavy also.

When my Rev 3 engine winds down off throttle, I'm getting a lot of Pop Pop Pop that sounds like gas going off in the exhaust. You don't have to rev it very high to get this result. Otherwise runs fine and starts very easy but this is annoying. Idle mixture screw does not have much affect until getting down to about 3/4 turn out when idle starts to drop. Plug looks tannish almost lean. This is a 250 with Keihin and stock jetting. Needle at mid position. What could cause this? Would it be a good idea to try a leaner pilot?

As copemech states, I would be sure about the big end bearing before changing. There should be no up and down play. However, there can be quite a bit of side to side rocking/ tilting. Put an indicator at the small end and measure side to side rock. I don't have a spec for a Sherco but some older Japanese bikes allowed 0.08". If you can find a Montesa 315 manual, it may have a good spec for reference. For main bearings, grab the flywheel and try to move it up and down. There should be no movement in that direction. There does need to be a little side to side movement. See 2-3 of http://dl.dropbox.co...15R_02_2002.pdf This shows big end tolerances.

These people may be able to help. http://www.westcountrywindings.co.uk/ If the plate is not available, a machine shop should be able to duplicate the one you have.

Someone was parting out a Rev 3 on Ebay UK. I believe the stator is listed.

Looking at more recent Beta cylinders, the number would represent the year the cylinder was cast. It would be for a bike manufactured in 91 or 92.

The idle mixture and idle speed screws for Betas are on the opposite side of the carb from most other brands so you would have to consider that. - EVO 125s come with the Keihin. Splat Shop sells Keihins and related items. - These guys sell Keihin knock offs but are expensive http://www.oko-australia.com.au/ - If you were happy with the original Mikuni, they show up on the UK ebay and you may be able to get one from a breakers. Beta would probably sell you one also.

I have had plugs that would fire in air but not under compression. Try another plug.

The holes were about 1.5 times as deep as the helicoil so I tapped them as deep as possible with the helicoil thread. Rather than installing up near the top per instructions, I installed the helicoils as deep as possible in the hole and was able to get good torque on the bolts. So far, it has held for one ride so maybe it will be OK. Is there a torque spec for these?

I put a Keihin on a 2008 200 Rev 3 and have just bought the idle mixture screw with flex attachment on the end from Splat Shop. Does something locate the knob that you turn with your fingers? It seems like there should be some kind of bracket.

The Beta 200 is a small bore 250, not a big bore 125 so you would have to swap the crank also.

The threads that hold one of the M8 helicoils are stripped. They are pretty close to an M10 so I would have to go to M12 for a good thread. There is not a lot of meat around the hole and I may not be able to open the skid plate holes that far either. If I drilled through for bolts and nuts, the far side is not flat to accept a nut. With some creativity, it may be possible to make a special shaped spacer to go between the nut and uneven shape but it would not be easy. I wonder if it will need to be filled with weld and redrilled? Based on the design, I doubt I'm the first with this problem.

I did a little more research. If you go to the Vertex catalog for the UK, they list GG200 pistons by sizes. The part numbers imply a letter but I don't know if that corresponds to the GG letters. http://www.gb.vertexpistons.com/

Do the rear mounting holes on a 2008 Rev3 have helicoils from the factory (steel thread type coils)? Mine has them but I can not get them really tight. On one side, it will get fairly tight and then the bolt threads strip. On the other side, the threaded coil worked its way out over time. Is there a solution?

These people sell many Keihin carb kits that come with needles. They also have a cute ad. Maybe they can help. http://www.ebay.com/itm/HONDA-TL125-KEYSTER-CARB-KIT-1976-/110783071864?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item19cb2f8678

After cleaning up the piston, I found it marked with 63.950 but no letters. This matches up well with my bore measurements. I don't see letters on the cylinder. A previous owner replaced the piston so could Vertex sell pistons direct without letters? Anyway, it is my buddy's bike and he is ordering through Lewisport so I passed the information on.

I'm measuring the top end of a well worn 200 pro but am getting a cylinder ID of 2.519" or 63.982 mm. I was expecting something about 0.0015" over 64 mm. Does anyone have specs on piston/ cylinder sizes for this model? The parts list shows B, C and D pistons but says nothing about size. Thanks!

I just put a 250 top end on a 2008 200 and am getting a POP/ POP/ POP when chopping the throttle. It is sort of like knock but I'm not sure what to make of it or what it is telling me. I think a small or occasional amount of this is quite normal on most bikes. Are 250 Betas more prone to this? Raising the needle to full rich helped but some of it is still there. Otherwise it runs OK. The plug looks OK. Starting and idling are good. This Mikuni has a 5C23 needle, 2.0 slide, 145 main and 30 pilot. Is the 250 needle or slide different? There is also a 66 stamped in the carb body on the engine side.

I like that idea. However, the ID of the bush is about 0.010 bigger than the pilot drill for an M10 x 1.0. Did it turn out to be a fairly loose fit on the bolts? Even though there was play of the OEM bolts in the bushes, there was enough variation in the all parts that there was no free play after full assembly. If they do loosen up, I'll try threading. Thanks

The sprocket to hub fit on my Reflex has a fair amount of play so I assumed it was all in the bushes. I'm in the process of replacing them but when I check the bolt to bush fit, they are not very snug. There is maybe 0.01 play. How tight are these when new? Should I be replacing the bolts also?

I found one for an evo but not Rev3. I wonder if they are the same? It is kind of odd to do that with a straight edge. I have always seen solder.

Does Beta specify a squish clearance for the Rev 3? They do offer base gaskets in different thicknesses.