dan williams

DId he just call me a bad mechanic?

Let us know how you get on. Knowledge shared is knowledge multiplied.

Cleaning up production tolerances never goes to waste. I didn't soak mine in oil as I didn't think it was a big deal. I just made sure they were free of detergent. Make sure you report back the results.

HI Pete, Just as a matter of course I did the tab polish to my '13 EVO 300. I didn't do the cleaning between the fiber pads as the glue used to hold the friction material was applied much better than the older plates. In other words it wasn't splashed over the whole plate nor was it so thick it filled the grooves between fiber pads. Even with cleaning the tabs the '13 clutch was too fast for me. When my hands got tired I had trouble modulating the clutch and was dropping stupid points. Near the end of the year I replaced the '13 fiber plates with a spare set of the polished and cleaned '08 plates and flipped the stepped washers/spring retainers and the '13 clutch is now much better. Easy pull even with six springs and super progressive.

Hi Starr, I'm unsure of the acetylene, caustic soda subjects except knowing they're dangerous. The pilot jet on a Mikuni is marked on the side. You'll see a little square logo thingy and a number. The main jets are marked on the top of the hex. Most two stroke carbs follow the same design where there are multiple circuits (air passages and fuel passages) for different throttle settings. The summary looks something like; Idle to 1/8th throttle, Pilot circuit 1/8th to 1/4 throttle, slide cutaway (That angled bit on the slide facing the airbox) 1/4 to 3/4 throttle, Needle jet and needle 3/4 to WFO, Main jet There is overlap but this is pretty much the map. The air for the pilot circuit enters in through those holes you see in the bell mouth of the carb. They also provide bleed air for the other circuits in the carb. The theory is really complex on how all these holes work. Think Doctor Who explanation of the TARDIS. All Fuely Airly wibbly wobbly. Not really necessary to know however. All you really need is the map above and to set the float height correct. There's a lot of good info on the sticky Mikuni thread at the top of the forum and the web is full of info on this type of carb as it has been standard on many two strokes over the years. Oh and when you clean the carb use compressed air to blow out the passages.

Usually if the choke isn't setting all the way you can tell by pushing on it with it closed. If nothing changes you're probably OK.

Sorry it didn't work out but you are right to walk away if it doesn't feel right. As far as pistons go these electroplated cylinders don't go through pistons anywhere near what the old steel cylinder bikes used to so a set of rings is usually a good refresh.

It's a common question for newbies. Glad you asked rather than just cranking the bolts down which usually ruins the hubs.

Check out the Mikuni thread sticky'd to the top of the forum. Float level and travel should be adjusted and a 27.5 pilot jet is used around here for operation at sea level. Check to make sure your choke circuit is closing all the way.

I bought a set from Saunders Extreme for my '08. Expensive but good quality and they looked great.

I think the simplest answer is the most likely. Somebody played motocrosser on a trials bike. Probably with straight gas once the tank ran out of whatever you had put in. The kind of cascade failure you are all trying to diagnose is pretty rare unless an engine is going like hell when it fails.

Did you do the clutch fix? Polishing the tabs helps with the slip as it allows the fibers to properly re-engage under torque. Another thing to look for is to make sure your adjustment on the bars lets the lever return far enough to uncover the reservoir port in the master cylinder. When the lever doesn't return all the way the heating of the hydraulic fluid causes expansion that would normally just flow into the reservoir. If the hole is blocked though the fluid pressurizes the system slightly disengaging the clutch. I think the springs are probably fine. You'd have smoked the transmission fluid before you reach the temperature necessary to take the temper out of the springs.

Mine did too at first. I moved them forward and that helped. You can get used to them but they do take some getting used to if you're coming off a Rev3.

Oh yeah, that does make you the cool kid on the block.

Since they were going with "right side up" forks the next year any prototype USD forks would likely just get bolted to a production machine once the decision was made on the '96. My guess is you got one of those, "Hey, Mario, wadda ya want to do with these prototypes?" "Bolt them to a bike. We've got no other use for 'em."

I'm still thinking you got factory forks there bucko.

Yeah Beta did that on my 08. Really poor grounding scheme as it caused the kill switch and lighting circuits to cross feed when the ground went intermittant.

peterh, That's interesting that you went the other way jetting with the Boyesens. I can't find MC1 anywhere around here. All I see is the H1R Bel-Ray which I run at 100-1 with VP C12 race gas.

Not that I remember but it's been a while.

As a guy who chases pico-amps for a living I maintain you can never have too many grounds. The earth on the coil is probably best as you are not relying on the frame but a direct connection through a wire back to the summing node in the stator. Personally I prefer to ground things in several places so when one fails I don't have to push out of the woods or even know for that matter. I am a strong believer in different grounds for ignition and lighting systems.

Anything grounded to the frame has to have the anodizing ground off to make good contact. I also use conductive thermal grease to keep the aluminum from reoxidizing.

Merry Christmas to all my fellow Betazoids. And a completely crash free new year.

Consistent fuel is great but there's often an advantage to tweaking the jets just a bit. On the mikuni equipped Betas I've owned dropping the pilot to a 27.5 was pretty standard around here for the '08 Stock jetting was fine with a needle adjustment. The '13 was a bit of a surprise. It felt a bit boggy off the bottom so I dropped the pilot to a 45 and it got worse. Going up to a 50 from the stock 48 cleaned it right up. Easy starting is not always the sign of perfect jetting. For example if the bike starts easy without choke on a cold day the pilot is probably a bit too large.

I drop to a ten tooth engine sprocket. As far as being obsessive for jetting it really is necessary. Jetting is all about test, tweak, test, tweak. It takes patience but the reward is a bike that pulls like a steam engine yet jumps like a scalded cat when you twist the grip.

I put VForce carbon reeds on all my bikes to smooth them out.. Boyesens would probably have the same effect of increasing crank pressure at low RPM and therefore increasing torque. Proper carb jetting is essential to get a smooth transition between the different circuits in the carb. I also drop one tooth on the countershaft sprocket which I find better matches the power and of the engine to my meager skills. You may want to disassemble and clean the carb with compressed air as the pilot circuit on the Keihin is notorious for getting blocked with dirt or even water. That will make the throttle response seem abrupt as the bike comes off the malfunctioning pilot onto another jet circuit and suddenly wakes up. Can make a bike very hard to ride.