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Derek Harris Added a reply to If Keefer races outdoors where does he finish?
4/8/2019 1:27pm Loretta's is "soft" but by our stds its hardpack clay base Much like hangtown looks to me along with highpoint, Muddy creek (gone) and freestone Anyways - I think the cooler thing we should do for Keefer is have a "if he makes it fund" Anyone want to start that up - little extra incentive for the guy?
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Derek Harris Added a reply to If Keefer races outdoors where does he finish?
4/8/2019 1:08pm It's nearly impossible to compare times without being there in person and seeing the track conditions and moto ride times BUT - at loretta's in 2017 keefer raced http://lorettas17.tracksideresults.com/class.asp?c=197&e=1 If you compare all three motos - vs browny - we can get an idea where he possibly can be In moto1 and 2 brown went nearly the same speed 1:59...
Derek Harris Added a reply to Anyone get inconsistent race sag numbers?
4/8/2019 11:34am and ML is correct Run the sag that works best - not what your told to. Depending on the valving and clicker settings, spring rates, fork height, rider style and body positioning - no two riders will like the exact same same number if tested blind on a set bike. When the 14 yz450f came out we found it worked...
Derek Harris Added a reply to Anyone get inconsistent race sag numbers?
4/8/2019 11:32am It's hard to get the exact same within 1-2mm I measure 5 times and take the average...as there is some stiction involved - body position, shock nitrogen temp plays a role adn fluid temp - a cold shock fluid (and nitro) measure diff than hot. I also suggest the riding bouncing a few times on the bike to get the...
Derek Harris Added a reply to Anyone had there 17 + KTM 2stk do this?
4/6/2019 4:04pm Very common The BEST way to avoid (doesn't matter for performance) ive found is upon first fire up and break in - castor 927 - and essentially idled/hardly any rev for a while - and about 1 hour of super easy run time at 28:1 But new engines from OEMS (and ktm) are dyno run at the factory - and...
Derek Harris Added a reply to Building the ultimate cr125 engine
4/6/2019 2:13pm They do for kart engines But at the power it has production - exceeding that of the ktm (or about on par with new 19) I think they don't want the headache of the powervalve complexity... The transfers are fantastic - and obviously where the power comes from vs a yz or ktm
Derek Harris Added a reply to Building the ultimate cr125 engine
4/4/2019 1:24pm The stock KTM is leaps better than anything raced - your a wise man. The TM is too...I recently knocked down 42 on a pump gas TM which surprised me for T port...
Derek Harris Added a reply to Building the ultimate cr125 engine
4/4/2019 11:11am They needed it! to answer - Mugen was very close to production cylinders of the time - pick a year to compare with for the variances...as honda had small tweaks over those years. The ex port was slightly higher, less than 1mm diff, and the transfers for all intents were the same. On the dyno it moved the power curve...
matt.3150 Liked a reply to forum topic Building the ultimate cr125 engine
4/4/2019 11:01am
I was told that the mugen cylinder exhaust is moved up 2mm and has bigger transfer. But I'm not an expert on Mugen, I'm more of a HRC guy. I'm building a 2002 Fonseca HRC CR125 right now, I have pretty much everything to build it. I have never seen an engine with the amount of work done to it before. The amount of work into the cylinder is just crazy, the amount of work into the cases is crazy. Same motor as American Honda ran in 2002 and Factory connection ran up to 2004.
This forum topic has 71 replies.
Derek Harris Added a reply to Building the ultimate cr125 engine
4/4/2019 10:05am For 2500 you can find out...
Derek Harris Added a reply to Building the ultimate cr125 engine
4/4/2019 9:13am I hear I hear I hear. But never do I see! Knowing what I know - I think a ton of numbers are inflated from the era. No different than the cr500's being total animals and unrideable - and yet vs a modern 450 they are tame. A production 2005 (to current) yz125 IMHO is as good or better than...
Derek Harris Added a reply to If Keefer races outdoors where does he finish?
4/4/2019 8:54am Yep - agreed It's hard to throw down a heater vs this 20 year olds with no kids and no job But, I hope he makes it in. That would be bad ass
Derek Harris Added a reply to If Keefer races outdoors where does he finish?
4/4/2019 8:34am No offense to him - as he is a BAAAADDD DUDE on a dirtbike, ESPECIALLY for getting older. I don't know how his body holds together. But I don't think he will make the fast 40
Derek Harris Added a reply to 19' YZ250F
4/4/2019 8:30am Curious why you are cutting mesh and adding holes specifically for low end power? I'd like to learn something new today! While the holes will help some - it's mostly all up top in my testing. Air flow becomes a power hindrance with RPM - as thats when the engine is needing the most flow.... The bike will SOUND way...
Derek Harris Added a reply to Building the ultimate cr125 engine
4/4/2019 8:15am The Mugen I just tested a few months back, with a brand new engine all freshly built, coupled to programmable ignition we spent quite a lot of time on, then tested actual works bills and PC pipe, along with consumer pipes of the period, along with consumer pipes available now all tested And we ended at a whopping 34 or...
Derek Harris Added a reply to Can the powers at be do anything to reduce injury?
4/3/2019 9:40am I keep saying it and every year it gets worse Bikes have progressed and rules have not. we axed 500's because the 250 became a better race bike We are there now - a 250f is nearly on par with a 450 now. And argue all you want - a modern factory 250f is faster than ANY 250 two stroke...
MotoSeat Liked a reply to forum topic PR Team TM Peak Pro Circuit to compete the 2020 West Coast Supercross Series
4/1/2019 8:21am
MotoSeat is on board with this project, we are working on helium filled seat foams and anti gravity seat covers to help with the unsprung weight of the bike.
This forum topic has 6 replies.
Derek Harris Added a reply to Stock/OEM Chain and Sprocket Quality? Replace or run it?
4/1/2019 8:19am Shy of SX ridnig, I haven't seen OEM chains break So I run the a new bike ALL STOCK for the first chain and sprocket change need - for me on a 450 that's 15 hours max. And I don't know why people push these to huge hour intervals. A broken chain due to neglect is super dangerous. This 15...
Derek Harris Added a reply to KTM Domination
4/1/2019 8:13am Not mine 2 kx450s both broke under 40
Derek Harris Added a reply to Why did you quit Racing Motocross?
3/28/2019 8:28pm I haven't officially quit - but I don't ride anymore like I want Last 2 years shoulder injuries totally stopped my riding ability. Turns out shoulders also stop a lot of other activities most MXer's like too! I personally think the rising cost of healthcare - and IMHO the absolute shitty quality crap shoot you get (great healthcare out there...