Yuma_Sloth

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About Yuma_Sloth

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  1. Great thread, I suffer from the ~ same issues, so here's what I've learned to date: (1) Rekluse EXP on YZ250 = pure sweetness (I run the CORE EXP 1.0, not EXP 2.0 and it works great on YZ250 2T, not as well on my '07 CRF450R w/ flameout issues, had to upgrade to EXP 2.0 on CRF), I now run with Maxima MAXUM EXTRA 15W50 exclusively (I use this oil for my CRF450R tranny & engine + YZ250 2T gearbox) since it seems to give best overall shifting & clutch action (better than Amsoil, Shell Rotella, Maxima MTL and Maxima 10W40 ... going to try Maxima 10W60 next, believe the higher 60W viscosity will help feel of EXP clutch engaement). (2) Small diameter grips helped me a TON with respect to reducing arm pump. I also found that the grip softness was an issue. My solution has been Renthal full diamond "hard." (3) FasstCo Flexxbars really helped overall feel + less jarring = happier arms / hands, I really like these bars. (4) Stock YZ250 lever = best in my opinion, I run a Work Connection lever and perch and I actually prefer the YZ lever blade (WC lever seems modeled after Honda OEM), It gives me better modulation w/ less effort. (5) Gloves were a big deal for me, too. I ended up going with One Industries DRAKO gloves, very similar to Fox Dirt Paws. Both seem to give me the "right amount" of grip and padding without inducing arm pump due to too much grip and too large of diameter. (6) I've tried Magura HYMEC clutches, nice product, but mine failed in a WORCS race. REALLY upset me. I'm flat out nervous to run them now. I was running an ASV lever on it at the time, so they (Magura) speculated it was that. I've returned to cables and bedn happy ever since. I hope this was of value. Best Regards, Tony
  2. I had the same thing happening on my 2006 YZ250. I normally ride a 2007 Honda CRF450R, so it felt really odd to me immediately. I didn't fret, as the forks provided good action and nothing was externally wrong, so I chalked it up to "Yamaha oddities" (all brands have got 'em!). Long story...but now they don't make that noise anymore. It was like the bike had been sitting too long and maybe there was some bleeding action that took place. Did you ever find a proof positive culprit?
  3. I had the same thing happening on my 2006 YZ250. I normally ride a 2007 Honda CRF450R, so it felt really odd to me immediately. I didn't fret, as the forks provided good action and nothing was externally wrong, so I chalked it up to "Yamaha oddities" (all brands have got 'em!). Long story...but now they don't make that noise anymore. It was like the bike had been sitting too long and maybe there was some bleeding action that took place. Di yo uever find a proof positive culprit?
  4. I appreciate the feedback guys! FYI, to add to your knowledge base, I did some more research and found that Zip-Ty Racing runs 15/47 for desert-type racing and 15/50 or 14/50 for WORCS racing on YZ250 2-strokes. Again, thanks!
  5. Just bought a 2006 YZ250. Will run in desert mostly + some WORCS races. Suggested gearing??? Any mods you highly recommend (e.g. V-FORCE reeds?)???
  6. Actually, I have what I believe to be the best exhaust for the 2003 CRF450. It's a Dr. D complete system. Motocross Action gave it their highest rating and I gotta say, it was a really nice improvement. It's still a torque monster, just more of it and more controllable. 5th gear wheelies are no problem and the exhaust note is not too bad. It also picked up a pretty healthy rev response, but again, very controllable - which is key to me. It's in great shape (I can send you pics if yo uemail me at tanderso777@hotmail.com) and was freshly repacked no too long ago. Price = $325 + shipping. FYI, I'm selling it because I bought a new bike. I've got other 2003 CRF450 parts. Just search the "Classifieds" area of ThumperTalk for "LOTS of CRF450 Parts." If you need some engine guards - got em! Like brand-new IMS desert tank - got it! You get the idea. :-) Thanks, Tony
  7. Yeah, really. The spark plug is new and perfect. My goal was to get KibbleWhite intake valves + valve train hardware to eliminate any reliability issues I could...while I had the head off to Eric Gorr, I decided to go with the Hot Cam Stage 1 to spread the power a little more. I like a W-I-D-E powerband. Additionally, I installed the Boyesen Power Shot to try to get rid of low-speed stalling. It did this about 60% as bad before, but I could usually get it fired back up within 1-3 kicks, max. Lastly, I put the '04 CRF450 piston in just to see what difference it might make. It definitely seems to make it easier to stall. To "undo" the crazy power this thing has, I re-geared to 14/48 (from 13/50)...I had wanted to do this all along anyway because I ride a lot of desert. So now I've got great power like I had before + I'm not hitting the rev limiter constantly. Overall, I like it a lot...but I'd like to get the low-speed stalling issue resolved and hot-starting back to a 1-2 kick ordeal. Yes, I modified too much at one time, but I was assured I wouldn't need to rejet...just fuel screw adjustments (which I haven't played with yet). This seems true based on how it runs 99% of the time. the other issue is that I don't have much time to incremantally tear into it and update the settings one-by-one, so I thought I'd jump right in and key on SIMILAR set-ups as a starting point and hopefully get it right in 1-2 iterations. That's where I am now. :-) I'm new to 4-strokes, so this whole thing is a worthwhile learning experience anyway. Hopefully what I learn and the specs I provide will be useful to someone else... I appreciate everyone's input!
  8. Yeah, really. My goal was to get KibbleWhite intake valves + valve train hardware to eliminate any reliability issues I could...while I had the head off to Eric Gorr, I decided to go with the Hot Cam Stage 1 to spread the power a little more. I like a W-I-D-E powerband. Additionally, I installed the Boyesen Power Shot to try to get rid of low-speed stalling. It did this about 60% as bad before, but I could usually get it fired back up within 1-3 kicks, max. Lastly, I put the '04 CRF450 piston in just to see what difference it might make. It definitely seems to make it easier to stall. To "undo" the crazy power this thing has, I re-geared to 14/48 (from 13/50)...I had wanted to do this all along anyway because I ride a lot of desert. So now I've got great power like I had before + I'm not hitting the rev limiter constantly. Overall, I like it a lot...but I'd like to get the low-speed stalling issue resolved and hot-starting back to a 1-2 kick ordeal. Yes, I modified too much at one time, but I was assured I wouldn't need to rejet...just fuel screw adjustments (which I haven't played with yet). This seems true based on how it runs 99% of the time. the other issue is that I don't have much time to incremantally tear into it and update the settings one-by-one, so I thought I'd jump right in and key on SIMILAR set-ups as a starting point and hopefully get it right in 1-2 iterations. That's where I am now. :-) I'm new to 4-strokes, so this whole thing is a worthwhile learning experience anyway. Hopefully what I learn and the specs I provide will be useful to someone else... I appreciate everyone's input!
  9. OK --- Spent the afternoon reshimming my valves. Here are the results: OEM valve clearances: Intake = .0063 +/- .0012 (.16 +/- .03 mm) Exhaust = .011 +/- .0012" (.28 +/- .03 mm) The bike had ~ 1.5 hours on the rebuild. Here's what I found: Left intake valve clearance = .0025" (.064 mm) --- way tight! Didn't expect that one! Right intake valve clearance = .004" (.102 mm) --- tight, too. Both exhaust valves = .010" (.254 mm) --- OK as-is, left alone. Adjust decompressor arm to .014" (while .010" feeler gauge measuring valve clearance inserted). After these adjustments, the bike started MUCH better hot. The issue now seems to be proneness to stalling out at low RPM when I'm making a turn. After a stall, the bike can be pretty hard to get restarted (but it starts!). It usually takes 5-6 kicks and I generally have to use the hot-start. If the bike is restarted after I kill it with the kill-switch, it usually only takes 1-3 kicks. Again, the bike runs well, but the hot-start and stalling thing seems to be bit of an issue...BUT IT STARTS MUCH BETTER HOT now...progress. Any ideas now? Will it get better with more hours? Time to rejet? Thanks again! Tony
  10. I'll check the clearances today and post it. Thanks for the feedback! Tony
  11. Hi, I just rebuilt my mostly stock 2003 CRF450. The bike has about ~ 90 hours total. Here's the PRE-rebuild set-up: (1) Dr. D pipe (2) Stock jetting Here's the POST-rebuild set-up: (1) Dr. D pipe (2) Stock jetting (3) Kibblewhite intake valves + valvetrain parts (4) Stage 1 Hot Cam (5) Boyesen Power Shot carb cover --- carb set to recommended settings + replaced diaphragm + D-ring and O-ring as Boyesen recommended (6) 2004 CRF450 piston (higher compression than 2003 version) So, now the detailed question: I have about 1.5 hours on the newly rebuilt engine. The bike starts cold like it used to. It runs and idles fine when cold. It even seems to idle fine when hot. The bike runs really strong when running and gives no indication of being difficult to start or any jetting issues. When the bike is hot, however, it's a NIGHTMARE to get started again. It usually takes ~ 10-20 minutes (and as many kicks as I have in me + a few more). The compression seems to go up, too, making it even harder to attempt to start. It just seems to start when ITS ready...ignoring My attempts. The Hot-Start button doesn't seem to do a thing. I am not giving it any throttle when trying to start it. I have NOT changed the jetting at all except the fuel screw as Boyesen recommended for the Power Shot. I live in Yuma, AZ @ ~ 200 feet above sea level. Also note that it seems to stall out slightly easier than before in corners, especially slower, uphill, 90-degree turns. Any ideas? Any help is appreciated. Thanks, Tony