AmSnow.com is now SnoWest.com
You have questions; we have answers. Hey, we're here to serve!
This spring we launched a new service for our Web users. We got several aftermarket companies to have their tech departments available to our online members. Now, instead of going several different places for advice, all you have to do is type your question into the forum and an expert will give you an answer. Pretty good deal huh?
Our panel includes reps from Dynatek Racing, Hauck Powersports, Speedwerx, Straightline Performance and G&G Powersports, several other aftermarket shops and our own staff.
Read on for some advice excerpts.
Asphalt drag racing coolerQ: I have a 2003 Firecat 500 and have it set up for asphalt drag racing with Boondocker nitrous. I'm planning on putting a water temp gauge on the sled in the ¾-in. hose that goes from the Mono head down.
At what temp is the sled warm enough and ready to go down the strip? After the run, what temp will the sled be? At what temp should I shut down and hitch a ride back to the pits? When I'm cooling the sled down with my cooling cart, what temp am I trying to get it down to? Should I buy a mechanical or electrical gauge? Thanks a lot!!
- Bradf5A: In a race application such as yours, the cooler you can run the motor, the better because it'll produce more power. Exactly what temp you will want to run will vary on clutch set-up, nitrous shot, pipe temp and so on.
Bottom line, you will have to test. Keep the motor as cool as possible, but remember you'll want the pipe hot when you take your run. I wouldn't suggest anything over 190 degrees on the return lane, but if you see a little higher readings, you should be OK. A digital gauge will most likely be easier to read, but both will work.
2002 Mountain Cat 600 boggingQ: I am having troubles with my 2002 Mountain Cat 600. My engine is bogging when I accelerate quickly, and gas mileage is way down. My stock 600 used ¾ of a tank while a 700 mod sled used less than ½ a tank on the same trip. My sled is a 600 stock machine with no mods on any part of the sled. I have not compared mileage with the other modded 700 sled before, but the low mileage surprised me, as I usually get a lot better - 17 to 18 mpg.
- Mountain Cat 600efiA: You probably have a stinky injector or one going bad. If that's not it, check to see if you have a cracked or broken reed. Also check the fuel pump as your pump pressure may be off.
2003 Cat ZR 900 EGT gaugeQ: I am about to install a dual digital LCD EGT gauge so I can keep an eye on detonation. The sled is a 2003 ZR 900 trail sled with D&D ported cylinders and cases, shaved head (the previous owner was not sure by how much) and bored carbs by Doc Fangs Performance. It has 660 main jets, a Tempa-Flow and twin ceramic-coated D&D pipes. Can anyone tell me what temperature range a 2-stroke twin should operate in safely, and at what temperature would you recommend I set the warning light?
The manual doesn't state the stock compression ratio, therefore I can't even guess what it is at now; a compression check reads 145 lbs. each. The timing is stock. I run 93-octane and intend to put the probes 10 inches from the cylinder.
- Just another aliasA: An EGT is a good tool to maintain a certain state of tune, but not a good tool to achieve the initial state of tune. It is better to first do spark plug and piston wash readings to set your carb calibration and make note as to what temp it is at certain throttle settings, you then maintain that state of tune by using the EGT.
Your readings could be in a range from 1,050-1,350, and that depends on ignition timing, probe placement, fuel type used and type of engine it is. Based on your initial info, I'd say temps at idle should be 400-450, midrange 1,200 and WOT 1,150-1,250. That is as close as I can guess. You may see temps hotter than that in midrange because of ignition spike at 6,000 rpm, but that should put you in the ballpark.
Rave valvesQ: How much backpressure is needed for the rave valves to work properly, and is it all due to stinger size or stinger size and muffler flow? I am building a custom muffler for my triple REV and I am wondering how to tell if it's too restrictive.
- F3doodooA: Very tough question just to give a straight answer. Rave valve pressure is adjustable with spring tension. Proper operation is dependent on the specific engine performance. Some require lower rpm opening while others require higher, the valve timing is typically correlated with engine torque to where they should open.
Cat flywheel lighteningQ: I see someone on eBay is selling the service of lightening the stock flywheel for Arctic Cats. I was wondering if this is worth the money or just leads to issues as far as not being balanced? Please let me know what you think. I would be having it done on a 1,108 race motor.
- someday I'll be fastA: We do not even do it on our full race motors. So no, I wouldn't suggest it.