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Fill in the corner with epoxy ? Trench the hump smoother ? Add epoxy to the inside of hump area to narrow it. Hump area has a X . Grind off the over hang from cylinder ? The rad valve is very close to the angled hump.
It was getting dark so pic is bad . See the rad valve how close it is the the hump in the corner .
Better pic
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Send that to TMR, Tom will make the most out of what you have….just understand it will never be as fast as a modern Yz125 or KTM group 125…this is coming from a guy who loves the Hpp CR125”s….
What does the OEM reed valve look like installed, the clearance on the top and bottom of the RAD valve isn't symmetrical, likely to be poor flow at the bottom...
You don't reed to do any work next to the reed cage unless there is interference. It is not a flow area.
I didn’t have the bolts in the rv, probably resting on the bottom. I wanted to see how close it was to the corner hump when it was in. And it was getting dark . I had tools scattered everywhere. Just curious if I narrowed the intake area with epoxy. That should increase the air velocity correct ? What kind of epoxy is used ? Thx. What do ya think of grinding the cylinder over hang into the intake track ? Some engine builders say you need that for reliability reasons. I think it blocks the intake flow quite a bit.
I,d rather do it myself. I,m trying to get it quicker as it is now . It is quicker out of a corner & pulling a hill than a Ktm. I won’t beat a Ktm at peak but corner to corner a quick responding engine with a strong & long mid is better. My 04 hits earlier than the new yz also. And it’s a very strong hit. I don’t see a yz pulling it out of a corner. I pulled a few new yz,s out of a corner into a steep hill. They had a blur bur b4 hitting, so it was easy. Deep sand on a fast track that could b a problem tho.
If I remember correctly, when you add material to the crank case of a 2 stroke, you increase the crank pressure due to the decreased volume of the air/fuel mixture which causes you to get a small bump in in power at low RPMs at the expense of power at higher RPMs. This is true if the crank volume was optimized from the factory and everything else remains equal. You can regain volume by using something like a Moose Racing "torque spacer". Frankly, you are better off leaving case reed motors alone on the bottom end unless you actually measure volume before and after any work and calculate where you are and need to go. You need a logical, well thought out plan and don't just "wing it". I have seen some epoxy work done but it is directly under the piston (pretty wild stuff). If I can find the pictures of this work, I will post them. Now, while the case halves are split, I would get them lapped by a reputable shop. Good luck with your project!
Ok Thanks for the info. I,ll just polish the cases good then. I could lap the cases myself a little. Get a sheet of plexiglass, tape 800,600 grit sand paper onto the glass. Dump some old fork oil on the plexiglass. And do some figure 8,s.
I wouldn't do that. You will end up with your bearings and seals fucked up again.
No offense but have you ridden a newer KTM 125 recently? There’s no chance you’re getting that gen Honda motor to wind out or pull out of a corner like or better than a newer Austrian bike will, and that’s coming from someone who had both at the same time.
Easy gains would be in the cylinder/case matching, if ledges exist that is.
Wrong the 04 can make huge power actually. The most of the CR’s.
Flow wants to be aimed up and into the transfers.
And adding or taking material out alters your crank case volume in relation to cylinder. Off note, Stews KX125 reed valve ran reed on the side as well for side flow. But its all a sum of all parts/mods combined. Get a sim program and do your changes on it to estimate your curve changes.
The best way is to remove the reeds, bolt the cage into place and look through the cage to see if any material is in the way. Most, if not all of that hump you are questioning is probably in a dead area of the cage.
For winding-out and pulling as hard as KTM's, there's only one chance. It's gonna be the STIC Super X carb. I've assisted a few 125 riders that get off track with tuning. Well it's very obvious once they get close to the carbs potential. Basically they always tell me that they could never have imagined that a 125 could produce such a broad and potent powerband. Also, I met a CR125 rider at the track and he said that he removed the STIC metering block bc it was too much for him. I told him I cured that issue on my 200SX with the slowest turn G2 throttle cam.
Ok Thx. I just polished the intake area & area by the crank. Then I got Real sick body tissue was freezing while sweating like crazy sat, sun. Mon I made it to a dr. He said your the 20th person to get all the flu test today. Nobody tested positive for any of the flu test. I tested positive for influenza A respiratory. I still don’t feel normal. I think I had it for weeks while on the rd.
Pit Row
I thought there would,ve been material to remove . I could,ve maybe added epoxy just b4 the hump. But the reeds r very close to the hump . Probably wouldn’t add much boost but I could get the bike to run crappy maybe. So I just polished the stuff up. Focus is to keep it running clean & keep maintenance up. Pistons & reeds . The 04 crank looks sooo good.
Not necessarily...
Need to atomize fuel mixture for more efficient combustion
The rad valve is taking care of that buisness. I didn’t see any material to grind off. So I polished it up. Air should flow in easier & faster. Then when the DBP gets a hold of it , Look out. Haha . Super quick & 1.7 ft lbs more torque than a Ktm. Ktm,s rip on top but I,m long gone b4 that.
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