CRF230F Piston Kit – Which One Is Best? [Wiseco/BBR/Athena]
Does your Honda CRF230 need an engine rebuild? I’m going to show you which is the best CRF230F piston kit for you. I’ll also explain why and when you should rebuild the top-end on your 4 stroke dirt bike.
Just want a quick answer? The Wiseco stock size piston (Amazon) is a great cheap replacement piston kit if you need a new one. I put one in a CRF230 engine of mine and it’s reliable upgrade with more torque than stock.
Why replace the piston in your CRF230F?
The two most common reasons why you’d want to replace the piston is if your CRF230F is worn out or you want more power.
Depending on the piston or top end kit you choose, an aftermarket piston can give you more torque and horsepower while staying reliable. This is because the stock CRF230 engine has a very low compression ratio to start with.
When to replace the top end of your CRF230F
Is your CRF230F top end worn out? These are the most common signs you need to rebuild the top end of the engine:
- Low compression
- Smoking out the exhaust
- Engine is making excessive noise
- Engine is vi
Do I need a new cylinder or just a honing job?
A new cylinder may be needed in addition to a new piston, but how can you tell? Even if you’ve never removed or installed a cylinder and piston before, there’s some simple signs to look for.
When you have the cylinder off, first look at the wall for wear. If you see any scratches or gouges, scrape your fingernail across it. Can you feel the gouge or line? If yes, then the cylinder should either be bored out or replaced.
These scratches are called “score marks” or “scoring”. Even if you smooth them out, your engine won’t have optimum compression, so it will be down on power and burn/smoke more oil out the exhaust.
Is the cylinder still in good shape with no scratches/scoring? You might be able to get away with a simple honing job.
However, to know for sure, you need to measure the cylinder with proper tools to get an exact measurement of the size and whether or not the bore is tapered (larger on one end than the other).
CRF230F top end rebuild – what’s involved?
Before you order your piston kit, you may or may not want to do the work yourself. With that said, with an OEM service manual, a top end rebuild on your CRF230F is not very difficult with the right tools and you take your time.
Here’s a basic breakdown of what rebuilding your CRF230 will be like:
- Remove gas tank
- Loosen cam chain tensioner
- Remove cylinder head cover, cam
- Unbolt and remove the cylinder
- Remove piston
- Install new top end parts
- Check timing before starting
Piston kit vs big bore kit
So now it comes down to how you’re going to rebuild your CRF230F and how to determine which is best for you.
Wiseco high compression piston kit (stock size)
Wiseco has an option for a stock bore size piston kit, which will keep your engine at 223cc displacement. You will get a mild bump in torque (especially if you use just one base gasket layer) because of the increased compression.
This doesn’t reduce reliability because the compression is so low to begin with.
I went with the Wiseco HC piston kit (Amazon) on my first CRF230F engine rebuild because it was less than $100 and was simple to do for more power. It’s still going strong after 4 years. All I did was a very quick hone job to get some fresh cross-hatching on the cylinder walls. This allows the piston rings to seat/seal better for the most compression when breaking in your fresh engine.
BBR big bore piston kit (high compression)
On my next build I went with the BBR big bore piston kit (Amazon) because I had a spare cylinder that was scored. I was able to bore it out myself, so that saved me from paying a machinist. Then I know it was done right and to size for the proper clearances.
This is a good way to go if you have a scored/junk stock cylinder and want more power with a basic piston kit.
However, the BBR piston kit is not exactly cheap. It’s noticeably more than a stock sized Wiseco piston kit (last time I checked). If you can’t bore it out yourself or know someone that can, then your best piston and cylinder replacement is the next option.
Athena big bore cylinder kit (high compression)
Is your cylinder junk and you want more power without needing any machining work? The Athena piston and cylinder kit (Amazon) is the best bargain. It’s not too much more expensive than the BBR piston kit, but it comes with a new cylinder already matched to the new big bore piston.
I did a review article on it that you can read here, but it’s an easy bolt-on upgrade in torque and horsepower. The reliability will be about the same because you don’t need to rev the engine as high.
Bottom Line For A CRF230F Piston Kit
Still unsure what to choose? Here’s your 3 options in a nutshell if you need a new CRF230F piston kit:
- $ Cheap With Stock Cylinder – Wiseco piston kit (stock bore size)
- $$($) Big bore with machining required – BBR piston kit
- $$$ Big bore with NO machining required – Athena big bore kit