Dear Ralph: I have a 1992 Indy 500 and I recently bought a PSI pipe. When I had the stock pipe in the needles were dropped one setting in the carbs to get rid of a nasty hesitation at half throttle. If I leave it where it is now... Read more

Dear Ralph: Where can I get the specs for trail porting my engine (Rotax 670)? Tom Scheideman Tom: There aren’t really any instructions, books, or sources that will give you exact porting specs for specific engines. One of the best sources of porting information is “Tom Turner’s Two Stroke... Read more

Dear Ralph: What is the best way to take the play out of my ’93 EXT steering ? My sled has 3000 miles on it and the play has been increasing every year. I was able to get at the pivot bushing on the right side. This appears to... Read more

Dear Ralph: I bought a roller secondary clutch kit last year based on all the good things I’ve been hearing, but I was not happy with the performance when I installed it. It just doesn’t run right, especially at low end. I know I haven’t got the calibration down... Read more

Dear Ralph: Please help me! I have a 92 RXL. The problem is that I can’t trail ride it. Running it hard on the lakes is just fine, but when you are on the trail it starts to “pop”, even when the plugs are new. Everything else is set... Read more

Dear Ralph: Much has been made of the multi-angle helix in the driven clutch. I’ve heard and read that it can substantially improve acceleration without hurting backshifting in most models. Snowmobile shows are rife with machinists that have “their own” version of this little item. They all claim that... Read more

Dear Ralph: Why are the OEM pipes so heavy ? If the aftermarket pipes are so much lighter and provide more horsepower, why can’t the sled manufacturers make their pipes that good right off the bat ? Are there some type of restrictions that limit their ability ? The... Read more

Dear Ralph: What is the difference between “case-reed” induction and “piston-reed” induction ? Are there advantages or disadvantages to either one of the methods ? On a case reed motor the carbs and reed block is mounted down on the crankcase instead of the typical location up on the... Read more

Dear Ralph: My dealer told me that when I buy a set of aftermarket pipes to make sure that they have rebuildable silencers. Why is this an advantage over the non-rebuildable types ? If the silencer has a “fiber-pack” it will burn out after about 2000 miles (or in... Read more

Dear Ralph: With the never ending emphasis on increased performance, why are we still seeing mostly round-slide carbs (Mikuni VM) on the new sleds? Especially since the flat slide TM and TMX carbs can provide an improvement in throttle response, tunability, and power. The flat-slide technology was developed over... Read more