bigbird2

I have a mystery question you may be able to help me with on my 2009 Evo 3004t that I bought used. This weekend the float stuck open/down for some reason and gas was coming out. This was eventually fixed just by the old trick of banging on the float bowl with a tool However in the process of investigation, I took off some of the things like the air box, etc. for better visibility and found an external hose configuration that was where the gas was coming out that I don’t understand. This is from memory but I THINK it is correct: There was a slip on fitting for a hose that came out of the right side of the carb near the rear at a height just above the center of the main air intake and angled down. It had a black rubber hose attached that was several inches long that went down near to bottom of the carb under the main air intake area. This black rubber hose slipped on to what once was a plastic “T” fitting except that one side of the “T” was broken off so that it was effectively a 90 degree angle elbow with an extra opening to the atmosphere near the corner (where the broken off part would have been). This is where the gas was running out. The remaining branch of the “T” fitting had a clear plastic hose on it that ran back up along the left side of the carb (near the back) and onto a slip on hose fitting that came out of the left rear side of the carb up near the vacuum diaphragm at the top. I couldn’t find any hint of a hose that would have once been attached to the branch of the “T” that was broken off??? After thinking of this I wondered if the “T” was some type of mod the prior owner added? as that would explain why I couldn’t find a hose that once went on the missing branch? The bike runs fine as configured (with both of these hoses going down to the “T” and being open to atmospheric pressure so I guessing they are both just VENT lines? The various parts and shop manuals don’t appear to address any of these external carb lines so I thought you folks may be able to help me? OR maybe you can point me to a source of a picture, etc. that shows these external tubes? THANKS!

Understand and agree. I have installed the heaviest spring I could find and it seems to be about right. What I was trying to say is that - by adjusting the rebound damping to max, it seems to be a good match for controlling the rebound of the stiffer spring without having to open the shock and change to thicker oil or other mods. The standard unadjustable compression damping seems OK with the additon of the stiffer spring and the benefits of the linkage.

FrankenBeta - This Thing is WONDERFUL!!! 09 Beta Evo 300 4t with EXTENSIVE mods (see below) to make it an ultimate OLD guy trail bike. The 300 4t is AMAZING and great for riding the really gnarly stuff AND should be good for me when I get too OLD and fat (I'm only 69 and 200 lbs. now) to ride my KTM in the dirt. Believe it or not, it is actually quite comfy to ride even sitting on the seat as long as you are not going really fast over rocks/logs, etc. Long Ride Kit (1.1 Gallon Aux Tank & Seat) Scotts Stabilizer BBR Seat at Normal Trail Ride Height 16" Rear Wheel (More Rake & Trail & Lower Pegs) Full Knobys 21" Front & 16" Rear 6" Rise Jitsie Handlebars Thicker Fork Oil in Right Fork ONLY for Increased Dampening Significantly Stiffer Front and Rear Spring Max Damping on Rear Shock Lowered Shifter Acerbis Rally Pro X Rally all plastic Handguards Tool Bag Under Seat Garmin eTrex GPS on Handelbar

Beta Evo Suspension Over the past year, I have been experimenting with the suspension on my 2009 Beta Evo 300 4t with the objective of making it suitable for a 200 pound 69 year OLD guy (me) to use it as a trail bike. This has included significantly stiffer springs on both ends and loaded sag set to about 2" on both ends PLUS a number of other MAJOR changes described in a separate post about my FrankenBeta :>) In the course of this experimentation, I believe that I have learned some things about the way the OEM suspension works and how to tune it, that may be helpful to others. Some of this information is contradictory to things said in earlier posts in this thread. I would welcome comments or corrections on what I am posting below. The left fork, with the spring and the ride height (or preload) adjuster is the old fashioned "damper rod" design. However, the passages for the oil are so huge that is provides almost no damping in either direction even if you use thicker oil. The exception to this is the anti-bottoming cone at the bottom of the damper rod. This device does nothing (no damping) until you are about 5" into the 7" of available travel. At this point it DRAMATICALLY increases the damping to minimize/eliminate the chance of actually mechanically bottoming the forks. Before I understood how this left fork worked I tried going to thicker oil in hopes of getting more compression damping. This did almost nothing for compression (or rebound) damping in the first 5" of travel. However, it made the damping in the last 2" of travel so firm that it effectively limited the fork travel to 5" or a little over. NOT good! Although I'm still experimenting, I suspect that, even with oil of the nominal OEM thickness oil I have gone back to, this anti-bottoming cone is overly restrictive and is effectively limiting travel by ramping up too much at the bottom of the stroke. The next thing I will try here is thinner oil. The other option would be to modify the shape of the cones so that the increased damping comes in more gradually through the last 2" of travel. In OEM configuration, it seems to be almost a step function from no damping to very firm damping which tends to make it unlikely to ever get into the last 1" of travel. Note that the right fork, discussed below, also has a short anti-bottoming cone which would supplement the damping in the last 1/2" of travel, thus providing some progressive increase in damping at the end of the stroke. The right fork has a modern adjustable cartridge for rebound control. It also has a very short anti-bottoming cone that is effective in about the last 1/2" of travel. The adjuster on this fork has a wide range of firmness even with standard thickness oil, however with thicker oil the maximum damping is substantially increased. Surprisingly, the use of thicker oil also has a very significant effect on compression damping. Thus, it is possible to increase the oil thickness to achieve the desired compression damping and then use the adjuster to dial in the desired rebound damping. I haven't really taken time to try to figure out whether the significant effect of thicker oil on the compression damping is from (a) the oil flowing up through the cartridge or from ( the oil flowing past the outside of the cartridge between the cartridge and the fork tube. I have done nothing to the rear shock except to max out the rebound damping adjuster to control the rebound of the substantially stiffer rear spring that I have install. This seems to work well.

Does anyone know of a source for Evo fork spring that is heavier/stiffer than the original? Thanks

I've just posted some info on DRASTIC mods I've made to an 09 Evo 300 4t and an 07 Rev 80 in the General forum. If you are squimish or a trials purist - I'd recommend you NOT read about these mods as they may make you ILL :>) BUT if you have a strong stomach - take a look (and give me you ideas on changes to make them even better/wierder :>)

I'm a GEEZER who has be off the dirt for 30 years. I just started dirt riding again and LOVE it. I've gone a little nuts on this dirt riding stuff and have bought: 08 WR250R with suspension mods, Power Commander, Autotune, FMF pipe, Scotts Stabilizer, Revlock, LHRB, etc. for Dual Sporting with lots of roads involved. 07 KTM 200 XCW with fork mods, lowered, TTX rear, Scotts Stabilizer, Revlock, LHRB, etc. for serious off roading. 09 Beta Evo 300 4t with EXTENSIVE mods (see below) to make it an ultimate OLD guy trail bike. 07 Beta Rev 80 with EXTENSIVE mods (see below) to make it an ultimate trail bike for my sweetie - But even though she did well on it, she decided it was a little too dangerous for a 67 year old gal, so she gave it to me as a play bike :>) So I've dived back in BIG time at 68 :>) Been riding every Dual Sport and all the options plus every trail riding opportunity I can find. Have made MANY great new friends and couldn't be happier. I did have one bad fairly high speed crash from hitting a rock on the WR250R (before the Scotts Stabilizer :>( which ended up with a brain bleed and emergency surgery plus a few days in ICU but have fully recovered and gotten sort of back in riding shape and am riding more than before. SO - If any of you are thinking of GEEZER riding - GO FOR IT! :>) My BETA Evo 4t was what I ended up selecting for EXTRA gnarly trail riding AND for riding after I get too old/weak to pick up the KTM. It is working out VERY well with the mods below which give it much more rake and trail and stability and make it much easier to ride. It starts VERY easily and is quite light so hopefully I'll be riding it for many more years. I'd recommend this bike to anyone trying to find an EASY to ride trail bike. 2009 Evo 300 4t - OLD Guy Trail Bike Long Ride Kit (1.1 Gallon Aux Tank & Seat) Scotts Stablilzer BBR Seat at Normal Trail Ride Height 16" Rear Wheel (More Rake & Trail & Lower Pegs) Full Knobys 21" Front & 16" Rear 6" Rise Jitsie Handlebars 20 Wt. Fork Oil & Max Dampening Stiffer Rear Spring Max Damping on Rear Shock Lowered Shifter Tool Bag Under Seat Garmin eTrex GPS on Handelbar As I said above I also got my 67 year old sweeting a Beta 80 which she gave back to me :>) It is SUPER easy to crank and ride and in some ways better than the 300. The little KTM 80 motor can GO and the bike is so light it's almost like a motorized mountain bike. The specs on it are as follows: 2007 Rev 80 2t - Originally Set Up for Wife Rekluse Auto Clutch LHRB - Left Hand Rear Brake Scotts Stablilzer BBR Seat at Normal Trail Ride Height 21" High Profile Front Knobby 3.50-18" Low Profile Rear Knobby More Front Preload & Stiffer Springs 20 Wt. Fork Oil Stiffer Rear Spring Lowered Shifter Quart Bottle of Premix Under Seat

This is not a direct answer to your question but something that may be a major consideration is the GEARING. I was considering a Montesa 4t until I learned from a fiend that it has a REDICULOUSLY large gap between 3rd and 4th gears that results in a 47% RPM drop on the upshift. My Beta 4t on the other hand has a much more reasonable 38% drop between these gears. It's not that a Montesa can't pull the 3/4 gap. Rather it is that it means you are often forced to choose between buzzing the engin and lugging it. Most any 6 speed (2T) will also have smaller gaps.

My 2009 Evo 300 4T generally starts and runs fine. However it has some eratic problem with fuel feed. The symptoms were as follows: #1 Bike started bogging with hard throttle them died. Eventually got it restarted and it ran fine for 5 mile return to home base. In this case the fuel level was low at the time of the original bogging/stall so I attributed it to something about not being able to consistently access the last bit of gas in the tank. In the process of restarting the bike after the stall I tried chock and manual override of the electric fuel shut off but don't know what finally did the trick. #2 At this time I had installed a long ride seat/tank but did not have aux fuel valve open. Again bike bogged then stalled. I assumed maybe out of gas so opened the valve on the aux tank. Took MANY MANY kicks to get it going again but it eventually ran OK for rest of ride. My only guess is that once float bowl was empty it wasn't refilling properly from the aux tank after opening the valve???? I subsequetly blew into the carb vent line and found it clear. #3 This time bike again bogged and eventually stalled. The main tank was nearlly full but I immediately opened the valve for the aux tank and started applying the choke. This time it started after a couple of dozen kicks and it ran fine for the rest of the day. Any ideas/suggestions appreciated. Could the electric main fuel valve be at fault? THANKS!

Thanks folks. Yes I wasn't pulling hard enough. I does stay out when I pull it a little harder!

Can anyone explain the actual function of the Hot Start knob on my Evo 300 4t? From looking at the Hot Start fix stickey, my GUESS is that it just adds some air in behind the carb? I don't see how that would help and the instructions for use seem strange/confusing. Mine is spring loaded so needs to be manually HELD in the open position (unless I'm missing something :>) THANKS!

When I look at specs for these bikes they all show the same 74KG weight? It doesn't seem logical that there is no difference between the air cooled and water cooled models. Can anyone help with the actual wieghts of any of these bikes? Thanks!

I'm a 68 year old guy looking for ways to keep me riding on our challenging Maryland terain and thinking of moding a sy250f - so this thread was VERY interesting. IF anyone has ideas for a good bike for me to make a trail bike out of please chime in. I currently have a KTM 200 XCW and a Beta 300 Evo 4t. The SY250F looks promising because it looks like it could be moded to add an auto clutch, normal space Yamaha gears and possibly even e-start. Thanks for any help