clarkp

Interesting Nigel - don't leave us hanging... how do we get in contact with John Lampkin? Does his business have a web site? I assume he / they are in the UK? More info please!

I don't think I have a problem with pre-ignition or detonation on this bike. The engine is almost brand new. I started with the 27.5 pilot jet, went up to a 37.5, down to a 35, and now back up to a 40. The bike still was pinging with both the 37.5 and the 35, so I'm up to a 40 for now. I need to put some time on the engine (get it hot) running the 40 to see how it behaves - next will be to go from the 145 main jet to a 150... small steps to see how the pilot circuit and main circuit work together - see what happens. I did get too aggressive with BillyT's float settings... I didn't have the float needle opening far enough and starved the bike for fuel when it sucked the bowl dry on a section-to-section transport... yanked it back off and bent the tabs to let the float needle drop down a little more.

Contact your dealer or the importer for your country - they can get you one, HOWEVER, the manual won't tell you much of anything about adjusting the clutch to make it work better. Try the usual... bleed the clutch line, change the fluid to something lighter possibly. When all else fails and you really want it to work like new again, order a clutch master cylinder rebuild kit from your dealer when you are ordering your manual.

Don't try to fix it yourself - if you screw THAT up your dad will REALLY be pi$$ed. Fess up - come clean and help your dad fix it. If he beats your a$$, so be it...take it like a man... lesson learned. At least now you know how much torque it takes to twist off a bolt - file that away in your memory, you'll need it later.

My '03 had ATF in it from a previous owner - presumably to reduce clutch drag. I spoke with the US importer and he strongly recommended against using ATF but to go back to a motorcycle transmission fluid or something in-spec per the owner's manual. I now use Torco MTF with fair results... by that I mean the clutch drags until it gets hot. I purchased a clutch master cylinder rebuild kit (haven't installed it yet) to hopefully help with the amount of fluid that gets displaced with each lever stroke to get the clutch plates to separate farther and reduce drag. Hope it works.

As an observer at a recent trial I had an unusual situation come up and I would like some opinion on how you would score this. A master rider launched over an obstacle to exit the section; his front axle was out of the section when he stopped and put a foot down outside the section, but his back tire broke the red tape because of where the bike landed. He had cleaned the section so I scored him a zero - should it have been a five?

dfwilson - here in TX I run 5 in the front and 4 in the back for most conditions (soft sandy loam, leaves, some rocks, etc.). On the granite west of Austin (Katemcy Rocks) and up in Tishomingo, OK this past weekend we were running 7 in front and 6 in back - I heard of no pinch flats or cut sidewalls. I weigh 180 lb.

How about an articulated bike that pivots in the middle for those REALLY tight turns!

hillbilly - some people take the fork stops out completely. If you are used to it you can 'saw the bars' in tight turns (turn super tight, then back off a little - repeat...) for some additional control. You might end up smacking your frame if you take headers as often as I do...

This is a partial list of some ideas that Billy T related in another thread... User programable ignition (on the fly) Rear fender attached to the swing arm (for greater clearance - and no broken rear fenders...) Foot pegs that rotate slightly for better balance. Replacable carbon fiber boot guard areas. Disc brakes that are inside the spokes attached to the hub. A single sided swing arm Gas inside the frame. Run-flat tires A weight of 120 lbs

So far, I've changed straight from a 27.5 pilot to the 37.5 (Traynor's suggestion) and things seem a little better - I won't know for sure until this weekend's competition and the machine gets run for a while (hot, real hot...) I am also going to switch from the BP5ES to either a BP7ES or the Champion N7YC or N7YCC (both cooler) and see what effect that has.

I too think the pilot jet could be the problem - Billy Traynor discussed the same type of problem with me about my Beta - when you chop off the throttle after a wheelie or a hill climb (any throttle on action) the engine is still producing a large vacuum from the throttle-on, but the pilot circuit isn't rich enough to satisfy the condition thereby you get a momentary 'ping' until the vacuum dies back to a partial or low throttle condition. My pilot jet was 27.5 (Mikuni) and I went to a 40 to start and have backed down now to a 37.5.

Mark - the '02 and '03 ignition modules are not interchangeable according to Commo. They have different connectors ('02 has a 5-wire rectangular plug and the '03 has a 2-wire oval connector) so my guess is that BC would have had to switch the 'brain' as well as the motor.

My bike is pinging pretty badly when it gets hot - trying to figure it out... I run 108 / 93 octane mix and 80:1 oil. Its got 145 main and 27.5 pilot jets and I'm running the jet needle one clip richer (second from the bottom). Its got an NGK BP5ES plug in it - is this the plug most Beta owners are running? Is there a stator plate with slotted holes on the Rev3 250 / 270 to allow small changes to timing? Any ideas?

Did you see from the "A Few Missing, do they know" thread when Billy Traynor registered here - what he's been working on? Here's an excerpt: A four stroke fuel injected trlals bike. Think of this 250 Four stroke Mikuni partial fuel injection Showa front and back suspension. User programable ignition (on the fly) Rear fender attached to the swing arm (for greater clearance) Foot pegs that rotate slightly for better balance. No sub frame Replacable carbon fiber boot guard areas. Disc brakes that are inside the spokes attached to the hub. A single sided swing arm Gas inside the frame. Run flat tires A heads up (HUD display inside the helmet) tach to tell the rider when to shift gears for better usage of torque range. A weight of 120 Ibls Four gears with the fourth one changable by the owner An electronic reverse gear switchable on the fly in a section. A memory chip for remembering what your score was in each section and what gear and rpm range that you rode it in. Now THAT sounds cool - let's see, Billy works for Mikuni, so is this just his wish list, or is this something that one of the majors is working on - I'm guessing either HRC / Montesa or GasGas. Now if it could just ride the section for me I could stay in the camper sleeping and sweep my class!

There was a fairly exhaustive post about this subject on the trials.co.uk forums. I think the upshot was what charlie suggested - play with the timing if you can - rotate the stator in the direction of crank rotation slightly to retard the timing (isn't it mounted inside the side-case?). Adding base gaskets does the same thing as adding head gaskets, BUT, it changes the port timing slightly.

Is it just me and my Rev3? I've noticed that when dropping down steep / long inclines my Beta acts like its trying to load up - kind of burbles a bit making me want to blip the throttle to clean it out (doesn't want to idle very well till the terrain flattens out). Is this only my bike, a Beta trait (raw gas getting dumped in the inlet tract when the carb throat is pointing toward middle earth), or something that happens on all bikes?

Switching them around makes sense to me, though the airbox intake would only be slightly higher than it is now... the bigger benefit would be that a lower fuel tank would yield a lower center of gravity making bikes even more stable by reducing the polar moment of inertia (look that one up...!)

Showa suspension and lots of new design time and goodies would lead us to think this is a new HRC / Montesa. Yes?

Naughty / Nice ? Who knows... I got new Hebo gloves and Hebo carbon helmet. :santa1: I guess Santa couldn't get an '04 Beta Rev3 in the sleigh... or maybe he's using it to deliver presents! I'll bet Santa would be a salty trials rider! :beard: Merry Christmas everyone!!

Is this Billy T's email: williamtraynor@hotmail.com ? This is from his post about Beta 'buretors.

Re-posted for future use; thank you Billy and RonM! Mikuni Carb Setup By Billy T After receiving my 02 Beta Rev 3 I am very pleased with the bike. I am getting quite a few recommendations on how to set the bike up and what areas to change or set. One particular area is the carb. I have heard many statements regarding the float level and how to set it up. This setting of the

Brilliant RonM! Thank you! :santawink:

Did anyone download Billy Traynor's thread from the trials.co.uk forums about float adjustments, etc. for the Mikuni carb? We need to get it re-posted on this forum under 'Bike Specific / Beta', or under 'The Mechanics'; and I need to save it on my PC.