Messages

1

General Two Stroke Talk / cr125 jetting questions

« on: June 16, 2013, 10:17:39 PM »

I don't think there is anything wrong with the Mikuni - no one complains on a yz and they are the same carbs....... Sounds like your float height/inlet needle might need changed as well as the float bowl gasket (or o-ring likely). About the most cost effective would be a carb kit if they are available for that bike, comes with all of the jets/screws/o-rings/etc. all in one package often for about the same price as you would pay for just the needle & seat. " title="Roll Eyes" class="smiley">

2

Technical / Re Gassing rear shock

« on: May 03, 2013, 01:31:09 PM »

There is such a small volume of nitrogen in the shock that when you check the pressure it will lose quite a bit. Plus, most of the shocks are at 150+ psi (ski-doo runs them around 300) The best way to check it yourself is to take the spring off and compress the shock, it should extend itself back out fully without any sticking or goofiness. You don't need to touch the valving to do this, just remove the spring.

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General Two Stroke Talk / Two Strokes & CMRC :)

« on: April 28, 2013, 10:16:19 PM »

 Easy now, I like Honda's  Noticed on the weekend that there are a lot more 2 strokes at the local races, I was the only 125 in the class for a year or two!

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General Two Stroke Talk / Two Strokes & CMRC :)

« on: April 23, 2013, 05:35:38 PM »

Nice little write up, first 250 2 stroke to do well in the pro class for a while!

http://www.cmrcracing.com/ofarrell-wins-first-race-back-on-ktm/

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Technical / 05-07 CR125 Setup

« on: July 15, 2012, 02:56:39 PM »

Soooo, here's the latest. I am finally satisfied with my jetting, it could be better but for the most part it is pretty good. I went with a -81 needle from a 2005 yz125 (middle position), a 32.5 pilot, and a 430 main. I kept changing and testing then went back to my original 'good' setup and couldn't believe how much better the new setup is, when I crack it - it goes My other setups would load up a bit as I decellerated into a corner and then have a very slight hesitation as throttle was applied, even on sharp corners where it's pretty much all clutch it was noticeable. So, if anyone else tries this let me know how it worked out for you.

6

Technical / 05-07 CR125 Setup

« on: May 28, 2012, 02:57:58 PM »

The 29-71 needle is a little richer in the midrange and leaner on the bottom (straight section) part of the needle. My needle is now 2.71mm dia. on the straight section where the stock is 2.68mm, the larger dia. has leaned it out nicely but it's still rich when just as I come off of the straight section. I wouldn't really care except that when I let off and coast for a sec in a corner as I open the throttle there is a slight hesitation that is the rich 'spot', I'm used to it but it's frustrating when I can set up everyone elses bikes but can't get my own just right.

7

Technical / 05-07 CR125 Setup

« on: May 13, 2012, 12:35:17 PM »

 The latest - my 6dgy29-71 needle finally came in (and installed, 3rd clip). Using it along with the stock 430 main, 35 pilot and around 2 1/4 on the airscrew, seems to be working fairly well but still goes rich off idle then clears out. Maybe I'll have to try a different slide with a little more cutaway, has anyone else tried a different slide? On a different note, had a full straightaway lead on the first lap last weekend in the vet class (the only 125 on the line) when I threw that away.....

8

Technical / yz 125 piston

« on: March 27, 2012, 09:49:03 PM »

Just like Vertex, it is nice to be able to match a piston to a specific cylinder, your manual will tell you piston to cyl. clearance and you can go from there. I think you mentioned it, but, every time you get a cylinder back from being replated/bored/etc. it should always be measured (just to be sure) and it will not necessarily match back to your original 'b' cylinder (or whatever it was)

9

Technical / 2003 rm125 jetting and float height

« on: March 27, 2012, 09:44:23 PM »

Get your float height set properly and then see how the jetting is, usually float height doesn't have a dramatic effect but that's the place to start. What is your airscrew set at?

10

Technical / 05-07 CR125 Setup

« on: March 21, 2012, 09:23:41 PM »

Doesn't sound like much is stock anymore! I like my suspension aside from the harsh bottoming on the forks, I weigh around 160-165 and have only had to set the sag. I managed to find a set of factory connection bottoming collars for the forks that should get rid of my fork issue (already raised the oil) and then it should be great So the latest on my jetting woes, down to a 35 pilot (32.5 would hesitate a little) and have tried a number of different needles. Even changed my crank seals just to be sure! Tried a stock '02 needle that was leftover from back in the day and it is finally lean off idle, this is the first I have been able to get my airscrew to actually affect the bike idiling. It is too lean above that but now I know what I need for a needle, 6dgy29-73 - but I don't think anyone makes it.... I'm going to order a 29-71 and give that a try because it's the closest I can come up with. Also, it seemed to rev out nicely! Sooo close

11

Technical / 05-07 CR125 Setup

« on: March 16, 2012, 03:21:35 PM »

Hope you get feeling better soon. I spun the carb. and changed my pilot to a 40 (was 45) and set the airscrew to 2 turns. The main is a 440 which seems good when I check the plug, I don't remember exactly what needle or position I'm running (maybe a 26-69 from an 04 right now) but it seems I still need to go one lower on my pilot. Ran out of time last night so maybe when I'm done work today I can tinker some more. Also, I'm at 1500' and running 91 unleaded at 32:1 with HP2 oil if anyone is wanting to try any of this jetting

12

Technical / 05-07 CR125 Setup

« on: March 15, 2012, 01:16:59 AM »

I did gear mine down one tooth but have the original sprocket on a spare wheel assy., Never tried them back to back though. Just got my first ride of the season in today and my track is a fairly technical 3rd gear track so I don't get/need to 'scream' it here. I have a rad valve that I picked up at the end of the season (on sale of course!) but haven't tried it either. Do you mind me asking what jetting you are running in you '06 supertrucker? I am going to drop one more on my pilot which I think is about a 40 right now because I went to tweak my airscrew and it was alreaday at 2 1/2 or so - these bikes were crazy rich from factory. I actually tried my spare side # plates from my '02 which were '04 plates, and yes, the plugs are out of the original ones on it now. Thanks

13

Technical / 05-07 CR125 Setup

« on: March 14, 2012, 10:16:46 PM »

Hello everyone out there, I have a 2007 Honda CR125 and have been working with it all last season trying stuff but it seems to sign off a little early on the top end. I had a 2002 CR125 before (with a crf in between there but that's a story of it's own) that worked well for me and I can't seem to get this one dialed in. I cleaned everything up to the ports in the cylinder when I did the last top end, have vforce 3 reeds, PC works pipe and R304 silencer and finally have the jetting in the ballpark (after a half dozen needles and about the same number of pilots). The bike works good but I don't ever remember the '02 running out up top. Just thought I would see if anyone else has come across this. I race the vet junior and mx2/3 junior classes and have had some repectable finishes but there are lots of times when there isn't time to shift in the last 20' and I need a little more...