2004 CR250 IT'S ALIVE (rings, reeds & thin gasket)
I had been toying with the Cometic high compression gasket idea for my 2004 CR250 for a while, but actually wanted to go thinner then what was being offered. I didn't want to have to run race gas, but was willing to if needed (still use it for my trips to the dunes). Here are the mods that I recently finished and let me tell you it feels like I am throwing my leg over a completely different bike then I had before all this.
From all the posts I could find everywhere on the internet, here is what I gathered on base gaskets. The stock gaskets are at .020 and Cometic .010 (both of them compress an additional .002 once the cylinder is bolted on).
Well when it came time to replace my rings this last week I decided to change a few things. This was the first new set of rings (so I know that helped some also) I have put in. The bike is a brand new 2004 model I got a sweet deal on because they wanted it off the floor. When I first got the bike I could tell the bottom to mid transfer was a little weak, but the mid hit was so crazy it was scary. It felt like a 125 powerband on steroids. First thing I did was drop the pilot jet from 32.5 to a 30 and that helped clean up the bottom a little bit and make it more responsive (im at 0-250 elevation). I pushed the main up from #420 to #430 to extend the top a bit more for over-rev. The bike ran ok like this for the last 6 months but was just uncontrollable. The wheel spin was so violent once the power hit. It really made it alot of work to ride.
Anyway on to the good stuff. I gathered the following parts:
1. Factory Rings $38
2. Boyseen carbon fiber replacement reeds $55
3. .002 thickness gasket material $3.99 (cutrate auto)
4. Redline Water Wetter $4.99 (cutrate auto)
5. Look on my face going down the railroad track for test ride - PRICELESS
Pulled it all apart and inspected everything. Cylinder still had the factory cross hatching and the piston looked great. Pulled old base gasket off and took my sweet time creating a new one from the material I purchased. When it got time to change the reeds I noticed Honda had already included carbon fiber reeds, but they were about half the thickness of the Boyseen. I also decided to put all the carburetor jetting back to stock until I knew more about how it would run. Put it all back together with a new sparkplug and held my breath.
Took about 10 kicks for the bike to fire up and took a minute or so to clean the little bit of motor oil I used to lube the cylinder during installation. It sounded great (93 octane pump gas mixed 40:1 with Dumonde Tech Oil). I babied it for about 5 minutes, let it cool down and then took it for a ride down the local rail road track. The bike flat out felt like a whole new ride and I know it wasn't just the rings that did it. I know the 2005 CR comes with a thinner metal base gasket for a reason :). The whole power band felt different and incredibly torqueier. For the first time since I have owned it, it acutally felt ridable from a powerband perpective. Like it was breathing better and not loading up, everything just felt like it had magically fallen into place like it should have from the show room floor. Only I know how different it feels and after riding it I wish I would have done this from day 1. Anyway, hope this helps anyone else out there thinking of the same thing. The only thing else I plan to mod is the silencer, thinking a pro circuit would be a nice addition to the stock pipe, hehe.. and I plan on trying some VP gas soon, Peace!
PS - Anyone else use the Redline Water Wetter as a replacement for antifreeze? It cuts radiator temps by up to 28 degrees. Running cooler means more power right? Well at least more reliability I guess :).
I had been toying with the Cometic high compression gasket idea for my 2004 CR250 for a while, but actually wanted to go thinner then what was being offered. I didn't want to have to run race gas, but was willing to if needed (still use it for my trips to the dunes). Here are the mods that I recently finished and let me tell you it feels like I am throwing my leg over a completely different bike then I had before all this.
From all the posts I could find everywhere on the internet, here is what I gathered on base gaskets. The stock gaskets are at .020 and Cometic .010 (both of them compress an additional .002 once the cylinder is bolted on).
Well when it came time to replace my rings this last week I decided to change a few things. This was the first new set of rings (so I know that helped some also) I have put in. The bike is a brand new 2004 model I got a sweet deal on because they wanted it off the floor. When I first got the bike I could tell the bottom to mid transfer was a little weak, but the mid hit was so crazy it was scary. It felt like a 125 powerband on steroids. First thing I did was drop the pilot jet from 32.5 to a 30 and that helped clean up the bottom a little bit and make it more responsive (im at 0-250 elevation). I pushed the main up from #420 to #430 to extend the top a bit more for over-rev. The bike ran ok like this for the last 6 months but was just uncontrollable. The wheel spin was so violent once the power hit. It really made it alot of work to ride.
Anyway on to the good stuff. I gathered the following parts:
1. Factory Rings $38
2. Boyseen carbon fiber replacement reeds $55
3. .002 thickness gasket material $3.99 (cutrate auto)
4. Redline Water Wetter $4.99 (cutrate auto)
5. Look on my face going down the railroad track for test ride - PRICELESS
Pulled it all apart and inspected everything. Cylinder still had the factory cross hatching and the piston looked great. Pulled old base gasket off and took my sweet time creating a new one from the material I purchased. When it got time to change the reeds I noticed Honda had already included carbon fiber reeds, but they were about half the thickness of the Boyseen. I also decided to put all the carburetor jetting back to stock until I knew more about how it would run. Put it all back together with a new sparkplug and held my breath.
Took about 10 kicks for the bike to fire up and took a minute or so to clean the little bit of motor oil I used to lube the cylinder during installation. It sounded great (93 octane pump gas mixed 40:1 with Dumonde Tech Oil). I babied it for about 5 minutes, let it cool down and then took it for a ride down the local rail road track. The bike flat out felt like a whole new ride and I know it wasn't just the rings that did it. I know the 2005 CR comes with a thinner metal base gasket for a reason :). The whole power band felt different and incredibly torqueier. For the first time since I have owned it, it acutally felt ridable from a powerband perpective. Like it was breathing better and not loading up, everything just felt like it had magically fallen into place like it should have from the show room floor. Only I know how different it feels and after riding it I wish I would have done this from day 1. Anyway, hope this helps anyone else out there thinking of the same thing. The only thing else I plan to mod is the silencer, thinking a pro circuit would be a nice addition to the stock pipe, hehe.. and I plan on trying some VP gas soon, Peace!
PS - Anyone else use the Redline Water Wetter as a replacement for antifreeze? It cuts radiator temps by up to 28 degrees. Running cooler means more power right? Well at least more reliability I guess :).
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