2 Stroke Aftermarket pipe question

[acw592]

I really hate to ask this question, seems like a stupid one.....but I was wondering how much of a difference an aftermarket pipe / silencer makes on a 250 2-stroke? I have a 03 KX 250 that needs a new pipe, currently has the stock one. It has a crack that leaks oil on the bend of the left side. I tried tack welding it a few times without sealing it. I was going to get another stock pipe until I bought my 03 RM 250. It has a FMF fatty pipe with stock silencer and aftermarket reeds, stock gearing. Both bikes have about the same compression and power but the RM gets there quicker. I can roost out of the corners on our track in 3rd without downshifting or useing the clutch. The KX I have to downshift or clutch if I want the same response. It has the same hit, only it is after the corner, takes a little longer to get there.
That makes me think the pipe has to help but when I tried to search this topic I found answers going both ways?

[dklassen]

Some bikes respond better to aftermarket pipes than others. If you change the pipe you'll likely have to change the jetting to maximize it's use. I owned a Suzuki RMX250 that had a double walled pipe to keep the noise down. When I put a FMF pipe on, it made a huge difference all the way through the powerband. It was also louder. Some pipes change the power delivery for more low, mid or top end power. I read a magazine article in the 90's where several pipes were dyno'd on a KX 250. It was quite surprising to find out that the stock pipe made a lot of horsepower along the power curve. It did show the difference along the curve for each pipe and did note that a dyno was different than the feel on the bike. I can say for sure that any pipe that is intact will be better than one that leaks!

[acw592]

This one has leaked as long as I've owned the bike. I keep thinking I would see a good used stock pipe on here or on ebay but I haven't found anything yet. Just not sure I want to spend that much money on an aftermarket pipe and silencer if it isn't going to make a noticable difference. Thanks!

[JS89]

I would get a PC works pipe and shorty 304 silincer and made a good differnce on my and then put a v-forces 3 reeds and made a very good differnce

[MXtras]

I always advocate spending the cash on riding lessons rather than accessories. However, in your situation (damaged pipe) I think an aftermarket pipe is a good option. The primary gains from an aftermarket pipe are that you can select a pipe that alters the power to match your preferences.

Never run a 2-stroke with a leaking pipe. This can be worse than running the bike without an air filter depending on where in the exhaust system the leak is.

Scott

[pjg351]

I've had success on 2 strokes by cutting down the stock silencer, try it on your old one first.

[TYSTYX]

I dont know about 250's, but it a proven fact that on CR500 the stock pipe makes the best power spread. The FMF pipes focus on bottom to mid power and the Pro Circuit pipes are a high end pipe. I switched from a FMF to a stock pipe and I like it much better. I still might try the Pro Circuit pipe. It will soften the bottom a little more than the stock pipe.....but its a 500 so theres plenty of power anyway, and I want more over-rev for the dunes and hills

[acw592]

I ended up buying a new FMF Gnarly for $127 on ebay. The Gnarly is the same pipe that's on my RM 250. I like the roll on power, makes a big difference on the bottom to mid. I just put it on last night, havent had a chance to ride it yet. Hopefully after work today!

[dklassen]

I had a Gnarly pipe on my 03 CR250. That bike really benefited from the FMF jetting specs. You can find them on their site. Just don't forget to adjust for elevation and temperature. I'm jealous of you being able to ride. Winter came to Saskatchewan this past week and I doubt that I can get out until late March or early April.

[yzernie]

There is never a stupid question. IMHO, you need to pick a pipe that suits your riding style. If you like a lot of low to mid power then an FMF Gnarly may be what would work best for you. If you like a lot of top end power then maybe the Pro Circuit would be a better choice. When I had my YZ 250 I put an FMF SST pipe on it and for my type of riding and my riding style it was the best pipe I have ever used.

I don't know much about the KX's or the RM's but 2 strokes are basically the same. You are doing the right thing by asking questions here at , also, read up on the net and then make a choice.