mokwepa Posted May 23, 2014 Report Share Posted May 23, 2014 Are you running the v-force reeds? I allways used the Boyesen dual stage to settle the Shercos a bit. Cheap to try!I wonder just how a 1mm change does compute? Prolly not as much as a 7000 ft change in altitude! Hi Cope. I have the v force reeds and am curious to know how they compare to std reeds or others. Why would someone change to vforce in the first place, ie what are they ssupposed to do power wise? Quote Link to comment Share on other sites More sharing options...
dan williams Posted May 23, 2014 Author Report Share Posted May 23, 2014 Mokwepa, the carbon reeds (or thinner/smaller reeds) have less mass so they will respond to airflow faster than the stock fiberglass reeds. For a given airflow they will open a little quicker and close a little quicker keeping more charge in the crankcase and hence more tranferred to the top of the piston. This only happens at low RPM though. At the higher RPM the airflow is such that it stops acting like a bi-directional pulse and gradually becomes a constant flow. The beauty of reeds over piston port or disc or any other intake valve for that matter is reeds are self adjusting to the demands of the engine. So for the reeds themselves it's all about the low end. Now with most of the accessory reeds you also change the reed block and that is the difference at higher RPM. At higher engine speeds the reeds are essentially stuck open and the reed assembly becomes a blockage in the intake tract. How much of a blockage is only one factor determining the maximum air fuel mixture the engine can pull in but it can be a significant one. Not so much on a trials bike unless you're Fujigas and he's on a four stroke anyway.The VForce reed block has eight petals where the stock Beta has four that are larger. I'm not sure of the flow rate difference. One thing to watch is the VForce block is plastic and I did have one fail. Fortunately the plastic piece and one reed blew right through the engine without damaging the top end. Much better than the old steel reeds bikes used to have in the old days. So to the original question, the VForce make the bottom grunt better. I can pull a gear higher with the VForce than with the stock reeds and it is much more difficult to stall the engine. As for the top end it's more than I can use anyway but the VForce seems to rev a little higher. ...and as for the original point of the thread I also ordered an S3 low compression head. I'll probably try that first before the gasket trick. A fool and his money are soon parted. In my case it's amazing we got together in the first place. 1 Quote Link to comment Share on other sites More sharing options...
copemech Posted May 25, 2014 Report Share Posted May 25, 2014 (edited) Hi Cope. I have the v force reeds and am curious to know how they compare to std reeds or others. Why would someone change to vforce in the first place, ie what are they ssupposed to do power wise? Yea, what Dan said, my take on it is some are more responsive at different levels of rpm. Thus, to possibly smooth one end, you may get more on the other. Dan expects a 300 to be gentile, and honestly I have never found one that I preferred over a good 250 myself. Edited May 25, 2014 by copemech Quote Link to comment Share on other sites More sharing options...
dan williams Posted May 25, 2014 Author Report Share Posted May 25, 2014 Oy my 300 the goy! Seriously, I've been privileged to ride factory Betas and they all ran very similar to my current 300. I love the grunt but the top end is savage. I'd rather tame it so I can at least use more of the engine without fear. I agree though I should probably have bought a 250 but old habits are hard to break. It is interesting to note the specified compression ratio on the 300 and 250 are vastly different and the factory bikes I did get to ride were Technos and Rev3s so their displacement was less of a factor in their power delivery than the tune of the engine. Of course as I get older and have less time and fewer places to practice I must admit to a harder time hanging on to a 300. Quote Link to comment Share on other sites More sharing options...
liviob Posted June 1, 2014 Report Share Posted June 1, 2014 I installed Boyeson 112 pro reeds in my 09 290. They softened the bottom hit and made the engine nearly stall proof. The engine is much more tractable than with the stock reeds. I can slow the engine down till i can count the pops and it docent stall. Most install the 665 power reed. Quote Link to comment Share on other sites More sharing options...
slicktop Posted June 1, 2014 Report Share Posted June 1, 2014 Oy my 300 the goy! Seriously, I've been privileged to ride factory Betas and they all ran very similar to my current 300. I love the grunt but the top end is savage. I'd rather tame it so I can at least use more of the engine without fear. I agree though I should probably have bought a 250 but old habits are hard to break. It is interesting to note the specified compression ratio on the 300 and 250 are vastly different and the factory bikes I did get to ride were Technos and Rev3s so their displacement was less of a factor in their power delivery than the tune of the engine. Of course as I get older and have less time and fewer places to practice I must admit to a harder time hanging on to a 300. Have you considered purchasing a 250 top end? The 300 is a handfull. I had no idea what the power delivery would be like when I bought the 300, and have never had a 2t this large and certainly not a bike weighing in at 147lbs. Besides getting a taste of the 300cc's awesome power delivery, when it first arrived a racing base gasket was in place and the bike was way too radical for a begginer such as myself. I promptly switched out the base gasket to something a bit thicker and the bike calmed down substaintually. Now I am running all new 2014 gear ratios in my 13 model. Besides changing the Primary ratio, the final drive is changed from 42/11 down to 41/10. The bike is more enjoyable to ride now. I skip first gear altogether and putt around in third or fourth and it will still explode with power at the twist of the wrist. Once I become more proficient in the sport, I will probably drop down to the 250 top end. Quote Link to comment Share on other sites More sharing options...
dan williams Posted June 1, 2014 Author Report Share Posted June 1, 2014 (edited) Yeah I thought of it but I like the grunt of the bigger motor. Part of the big power hit is ignition timing but I think the main difference is the compression ratio and not so much displacement. Speed of flame front sort of thing. I've already lowered the ratio with a 10 tooth sprocket. There are many options but like all tuning it's best done incrementally. As for the gasket my calculation showed just adding 1mm dropped the compression ratio from 10.2:1 8.9:1. Pretty significant. Of course I don't know what the stock gasket is. Edited June 1, 2014 by dan williams Quote Link to comment Share on other sites More sharing options...
slicktop Posted June 7, 2014 Report Share Posted June 7, 2014 I installed the thinner clutch plate with the tophats turned inward and the 300 is much smoother. It has certainly calmed down and I feel more comfortable giving the gas to climb. It is setting 3 in the clutch mod. Quote Link to comment Share on other sites More sharing options...
dan williams Posted June 7, 2014 Author Report Share Posted June 7, 2014 Well tooled around the yard with the new chamber. Easier to kick and a little mellower at the upper mid but still a 300. Event Sunday so I'll see if I've tamed the beast. Started first kick. Also installed the bigger impeller kit recommended by my dealer. Quote Link to comment Share on other sites More sharing options...
dan williams Posted June 9, 2014 Author Report Share Posted June 9, 2014 I like it. Still pulls like a locomotive but the sudden hit has been transformed into a nice linear curve. Quote Link to comment Share on other sites More sharing options...
slicktop Posted June 9, 2014 Report Share Posted June 9, 2014 I am really digging the changes made on my rig. Now I have to actually input some throttle for the bike to jump up and say Hello. I pulled my first real jump this weekend. It was probably insignificant to most, and certainly to this bikes former life, but to me a 5 ft.vertical leap is pretty radical. The first attempt I stalled out on take off but the second try was like a slingshot. I was on top of the ledge standing straight up on the back tire like a pro. I was shocked and grinning from ear to ear. I put her in the barn after that move, not wanting to push my luck. Quote Link to comment Share on other sites More sharing options...
lantz Posted November 10, 2015 Report Share Posted November 10, 2015 Dan, How much did you feel the kick getting easier from installing the low comp head? And did you install the extra 1mm gasket also? I'm trying to make my 54kg wife able to kick start her(our) 13' 300 factory. She rides it around the woods for trails-riding while i have the enduro bike. Just a little hassle to have to llop back to her to start it every time she stalls it. Quote Link to comment Share on other sites More sharing options...
lbhbul Posted November 10, 2015 Report Share Posted November 10, 2015 (edited) Just a slight word to taming of the shrew, and what was and still is a 321 Gas Gas fix we have used and all the squish folks will not agree with, .100 head spacer with o-ring grooves certainly calmed things down and improved tractability, starting, and still all the hit required. This will work, try it you'll like it. Larry Edited November 10, 2015 by lbhbul Quote Link to comment Share on other sites More sharing options...
lantz Posted November 11, 2015 Report Share Posted November 11, 2015 If I drop the comp with an additional gasket or the low comp head. Do I need to adjust the carburator? And if so, how? Do anyone know how much the low comp head drops the comp? As Dan says, the 1mm gasket drops it all the way to 8.9. Pretty significant, and for roughly 1/10th of the price of the head+headgasket. tempting. Quote Link to comment Share on other sites More sharing options...
dan williams Posted November 11, 2015 Author Report Share Posted November 11, 2015 I didn't on mine. Actually I did and it ran lousy so I went back to where it was. It will depend on your bike. You are going to have to ride and figure it out for yourself. There is no magic recipe for jetting. Quote Link to comment Share on other sites More sharing options...
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