neo Posted July 16, 2010 Report Share Posted July 16, 2010 (edited) High compression head (came from a mate in canada) Look out for them second hand. Does anyone know where I can buy one of these for a 125? Best of balance. Neo Edited July 16, 2010 by Neo Quote Link to comment Share on other sites More sharing options...
tony27 Posted July 17, 2010 Report Share Posted July 17, 2010 BVM list them for 125s,250s & 290s so they'll be a good place to start Quote Link to comment Share on other sites More sharing options...
sirhc Posted October 6, 2010 Report Share Posted October 6, 2010 (edited) Here's what I've ended up with on my son's 2010 125 S3 Head with the High High compression insert. Had just the High compression, but didn't make much difference so we went with the "High High" and it really helped out. S3 Titanium pipe with reducer. Don't think it really makes that much of a difference, I just had it from another bike. OKO 24mm carb with Keihin slide and all internal parts. Really helps out the bottom end and bike runs very clean. Still revs out like a good 125 should even with the smaller carb. The stock OKO slide pretty rough cast, so went with the better Keihin slide. It is a little bit temperamental though, often requiring changes in the air screw position depending on the weather. 48 tooth rear Sprocket. As far as I'm concerned the best mod for the 125. Definitely not too low for the better riders either! Now that he's getting better I was thinking about getting his flywheel lightened too. Edited October 6, 2010 by sirhc Quote Link to comment Share on other sites More sharing options...
neo Posted October 6, 2010 Report Share Posted October 6, 2010 (edited) 48 tooth rear Sprocket. As far as I'm concerned the best mod for the 125. Definitely not too low for the better riders either!Now that he's getting better I was thinking about getting his flywheel lightened too. Awesome update Sirhc .... thanks for that. Interesting that you have lowered the overall gear ratio...where as only yesterday I fitted a 10 tooth (from 9 tooth) front sprocket on our 125 because it was zipping though the gears like a rocket...still has tons of low-down pull and one test rider commented that it rode a bit like my 250 even Also, when you have the flywheel lighten would you do me a big favor and let me know what the final flywheel weight is? Best of balance. Neo Edited October 6, 2010 by Neo Quote Link to comment Share on other sites More sharing options...
copemech Posted October 7, 2010 Report Share Posted October 7, 2010 I think Neo will soon find third gear useless with a 10/44 set on the bike. Luckey if it will hold 2'nd on a hard climb, as if it drops out of the revs at all, will not regain. The 24 OKO might just be the hot setup on the 125, the friggin thing is still working on my 2.9, and I would find few who wanted more on top! Quote Link to comment Share on other sites More sharing options...
copemech Posted October 7, 2010 Report Share Posted October 7, 2010 Awesome update Sirhc .... thanks for that. Interesting that you have lowered the overall gear ratio...where as only yesterday I fitted a 10 tooth (from 9 tooth) front sprocket on our 125 because it was zipping though the gears like a rocket...still has tons of low-down pull and one test rider commented that it rode a bit like my 250 even Also, when you have the flywheel lighten would you do me a big favor and let me know what the final flywheel weight is? Best of balance. Neo Spec I heard was to lesson the weight by 1 lb. on the lathe. One could play at 1/2. Quote Link to comment Share on other sites More sharing options...
shercofray Posted October 7, 2010 Report Share Posted October 7, 2010 Awesome update Sirhc .... thanks for that. Interesting that you have lowered the overall gear ratio...where as only yesterday I fitted a 10 tooth (from 9 tooth) front sprocket on our 125 because it was zipping though the gears like a rocket...still has tons of low-down pull and one test rider commented that it rode a bit like my 250 even Also, when you have the flywheel lighten would you do me a big favor and let me know what the final flywheel weight is? Best of balance. Neo I run 9t front and 48t rear and that is the way to go i think, only thing is you have to get the 1 and a 1/2 link for it to fit, and with the flywheel it all depends on which faces you take it off for it to have the right effect. When you get it right it's awesome! Quote Link to comment Share on other sites More sharing options...
sirhc Posted October 7, 2010 Report Share Posted October 7, 2010 .where as only yesterday I fitted a 10 tooth (from 9 tooth) front sprocket on our 125 because it was zipping though the gears like a rocket. Neo, When you say zipping through the gears, is the bike being used for more trail riding than riding just sections? My son uses mainly first gear and sometimes second for sections. Quote Link to comment Share on other sites More sharing options...
neo Posted October 7, 2010 Report Share Posted October 7, 2010 Yes my description made it sound like we're mainly trail riding but we're not....Having said that the bike needs to be usable on the flat too and it was getting up into 3rd just 20 feet from start-off so it was kinda crazy and there's NO WAY I would have made the ratio lower. Anyway I'm still testing the 10T on the rocks but early results are very promising for our 125 anyway. 1st to 3rd still seems to pull up anything but admittedly I've yet to test 3rd on longggg hill climb....might do that in a few days time. Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
copemech Posted October 8, 2010 Report Share Posted October 8, 2010 Yes my description made it sound like we're mainly trail riding but we're not....Having said that the bike needs to be usable on the flat too and it was getting up into 3rd just 20 feet from start-off so it was kinda crazy and there's NO WAY I would have made the ratio lower. Anyway I'm still testing the 10T on the rocks but early results are very promising for our 125 anyway. 1st to 3rd still seems to pull up anything but admittedly I've yet to test 3rd on longggg hill climb....might do that in a few days time. Best of balance. Neo Shake that WD stick all you like, but it won't pull big stuff in third with that gear, nor second! Quote Link to comment Share on other sites More sharing options...
neo Posted October 8, 2010 Report Share Posted October 8, 2010 Shake that WD stick all you like, but it won't pull big stuff in third with that gear, nor second! Maybe so Cope. I've not tested it so can't comment....But in many ways, when 2nd gear has been ratio'd up close to what 3rd used to be, why would it need to?...why not just ride up in 2nd?I'm sure that much of differences in opinion here are because of the different terrains we ride ... But I am finding it good for ME! (so far anyway) Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
copemech Posted October 9, 2010 Report Share Posted October 9, 2010 (edited) Maybe so Cope. I've not tested it so can't comment....But in many ways, when 2nd gear has been ratio'd up close to what 3rd used to be, why would it need to?...why not just ride up in 2nd? I'm sure that much of differences in opinion here are because of the different terrains we ride ... But I am finding it good for ME! (so far anyway) Best of balance. Neo This is very true, and depends on what one is doing with the bike. I think it takes some Reverse Thinking here for big bike riders. My old '03 1.25 was just fun to ride, the newer ones do seem to have a bit more off the bottom, yet ultimatly there is only soo much one can get out of a 125 without narrowing the power range even more and sometimes I took it out just to see what it would do. Speed is not always the key, yet the ability to stay within the narrow power range without bogging the motor so it keeps pulling and does not fall off to a point to which it cannot recover under the load. The lower ggearing seems to act to widen the power range(not speed) and is why they (top lads) use it as compared to more easily falling out of the range with a change in speed. I used some creek banks at about 3 meters tall to test 2nd gear at WOT(stock gear), a rollup which goes near verticle and a bit of a rolloff at the top for insurance.. Even at full revs and WOT, the load would drag the motor down to the point it was questionable to get over the top. In first gear, it just kept revving and digging till you shut it off. If one were to ask Shercofrey what gears he runs in the sections, and even with his 48 on the rear, one might find that he seldome gets beyond second, cause it will still carry the ultimate load, not totally sure if third will, even on that gear, probably have to use care and speed! Even thouth the 125 does have flywheel inertia at revs, being lighter, it is quickly lost. Edited October 9, 2010 by copemech Quote Link to comment Share on other sites More sharing options...
basher Posted October 12, 2010 Report Share Posted October 12, 2010 (edited) have you tryed tweaking your suspension set up, may be try more preload and damping to get more spring for big ups. instead of trying to get more power. Edited October 12, 2010 by basher Quote Link to comment Share on other sites More sharing options...
sirhc Posted October 28, 2010 Report Share Posted October 28, 2010 (edited) Here's what I've ended up with on my son's 2010 125 S3 Head with the High High compression insert. Had just the High compression, but didn't make much difference so we went with the "High High" and it really helped out. S3 Titanium pipe with reducer. Don't think it really makes that much of a difference, I just had it from another bike. OKO 24mm carb with Keihin slide and all internal parts. Really helps out the bottom end and bike runs very clean. Still revs out like a good 125 should even with the smaller carb. The stock OKO slide pretty rough cast, so went with the better Keihin slide. It is a little bit temperamental though, often requiring changes in the air screw position depending on the weather. 48 tooth rear Sprocket. As far as I'm concerned the best mod for the 125. Definitely not too low for the better riders either! Now that he's getting better I was thinking about getting his flywheel lightened too. Update-- Since going to the High High compression insert it's been blowing the inner head o-ring out next to the head bolts. Tried a few different things, but nothing has worked. I didn't notice any problems with just the High compression insert until I took it apart and the o-ring didn't look so good. It looks like to me that the groove for the inner head o-ring comes closer to the grooves in the cylinder for the stud o-rings than the stock head does and that's why it's getting pushed out. Stock head back on now. I also found that the 2010 flywheel is already lighter than the 2009 and earlier flywheels. Not sure if we want to go lighter or not. Edited October 28, 2010 by sirhc Quote Link to comment Share on other sites More sharing options...
neo Posted October 28, 2010 Report Share Posted October 28, 2010 Thanks for the update sirhc, Could you do me a favour a and weigh that lighter flywheel when your in there next? Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
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