FTZ Performance, Inc. ATV F.A.Q. (Frequently Asked Questions) I've found that Two-Stroke ATV racers are full of basic questions, and mis-information in general. You can blame this on a lack of good tech articles in the magazines. Here is a few we get asked often; I've got the “Stage 14 1/2 porting but I'm getting beat”; Sometimes I want to say “Oh, I'm sorry,but:....A port job is not a port job!" Most people don't realize how critical the porting is on a modern two-stroke motor. The difference between a good one and one that looks good but doesn't make the power is very small. Years of dyno testing have taught us that if the ports are off as little as .010” the power can be down 4 or even 5 horsepower! This fine line is not only hard to find but takes tremendous skill to grind. I am continuously amazed at what passes as good portwork. (I.E.) how little work is done in the hard places to get to (the transfer ports) and how the exhaust and intake are often hogged out too big. We actually re-port (fix) many previously ported cylinders for customers. It takes a long time to do it our way but it is very important both to making big power and having a wide powerband. “They know what they are doing because they have a dyno”; My response is usually, “ A dyno is a tool just like a hammer, you can fix something with it or you can screw it up with it, depending on how skilled the operator is.” Reading dyno charts is like a doctor looking at a "cat scan" or x-ray, the obvious is not the whole story. Then.... you have to know what to do to make it better! Another clue; if the dyno runs off tires and doesn't have gobs of sensors and wires to it, you might as well test ride the darn thing-- it will tell you about as much. I've got a Fatty pipe already.” Okay, this one really fires me up. Just as port jobs are not the same, pipes are even more different. There are good skinny pipes and bad fat pipes and torque and rev versions of both. Dyno testing and knowing what you are doing is what makes the best pipes. We have as close to the ultimate 250 pipes as you can get. Here is why; (1) We dyno test BIG TIME. We take the best pipe and cut it apart to change cone angles, lengths, etc. After 10 or 20 times we hope to find something a little better. Then we repeat the process all over again. (2) We know what we are doing. (I started making race pipes in 1972) This lets us make progress when we dyno test instead of going backwards. “Methanol is corrosive and is hard on seals.”; Who got methanol confused with battery acid? The biggest thing to look out for here is the alcohol will absorb moisture and water is corrosive, (on steel, it's called rust) and you don’t want it on your bore or crank bearings. Run a gasoline/oil mix thru the motor before you put it up for the week and problem solved. A 1 gallon jug with a fuel line fitting works great. Just hang it from the handlebar and run in neutral for about 5 minutes. "Should I raise compression and add timing with alcohol?" Well it depends...on how good your stuff is! We have found that our motors will make best power with no more timing or compression than is best with race gas. This is because first our Alky carbs mix the fuel very well making a easy-to-burn mixture. Also our heads and ignitions optimize the combustion process. Your wimpy ignition, poorly shaped head, and a carb that poors in wet "un-burnable" fuel may have to have more timing or compression to even run on methanol. But that will only be a "Band-Aid" and doesn't make it the correct way to best power.

“How much Compression should my motor have?" We get this one all the time...We don't concern ourselves with cranking pressures! It tells you nothing! Remember this: Cranking pressure is only a product of several other factors including displacement, head & dome volume, squish clearance, and exhaust port timing and some other things such as altitude/air density and even how much hose is on the gauge! We cut our heads and domes to exact shapes that our experience tells us will give the best power without promoting detonation or excessive combustion turbulence. We have done much cutting edge research into this area. This is a often misunderstood field by most engine builders. Trust us to get it right for your motor. “My jetting is okay because the plug is dark”; I love this one...... A few minutes with a warm motor at idle or slow speed will darken a plug and the mixture can still be dangerously lean at the torque peak. There is only one way to know what is rich: that is make it too rich! Jet it up to the point where it blubbers and misfires at wide open throttle (say 3rd or 4th gear). Then you can lean it down a little at a time until it runs clean. Do the same at half throttle, with the needle position. “I have a new exhaust temp gauge -What should it read?”; Boy this is a tough one, because there are so many variables. Generally the EGT builds as load is applied and raises with time under load. A racer can check it at the same place on the track & after the same amount of time and get a consistent reading, otherwise it will change constantly. Other factors such as high compression and advanced timing will lower the EGT while trying to burn a hole thru the piston. I told you it was a tough one! You will have to work out your own numbers for your particular situation. “Somebody said there is no way you make 75 Horsepower out of a 250 - My 500 only makes 62 hp!”; Believe it! It is a real deal...(Remember, 9 or 10 HP difference between our alky carb and a gas carb.) Keep in mind that what determines how much power is made, is a matter of how much air a motor can pump through it, (It’s the air & fuel that makes the power, not the parts involved.) Think about it this way...Our 250’s rev to over 11,000 rpm. That is 3000 RPM more than most 500’s and 1500 more RPM’s than most big Banshee’s. That’s why the 250 power output can actually be higher than the bigger motors plus having a wider powerband and lighter weight. "My 330 getting beat by a 250": Same as above! What’s new: Our new Powervalve 250R motors at 265cc to 370cc offer awesome performance, without welding up the crankcases. We think our Trx 370R powervalve motor with our pipe, intake & ignition is the fastest Honda package we have ever offered. Our SuperFat Drag pipes are now available for the Banshee's and we recommend them for the big bore aftermarket cylinders. Call for more details and prices on these both.. I hope this can help you, Jon @ FTZ

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