Hi there Randy, I have a bevy of questions for you. I might be suffering from information paralysis analysis and would appreciate your help. I've been thinking the KTM 300 2-stroke is the way to go, some nice advantages over the 450 mx bikes -- .....but then I am also seeing a lot of older 500's for sale. Have read your build post several times. Wondering what bikes would be best for snowbikes? I don't mind spending more for a ktm 300 if that is an overall better way to go; I also don't mind spending $2-2.5K for a 500 if it doesn't make much difference. Would run a SmartCarb either way.
Unrelated question, what would be involved in installing a SmartCarb on an EFI bike, cost-wise and labor-wise (what would have to be done exactly to make it work)?? Thanks much, any help is appreciated.
Alan,
Great questions. After countless hours in the shop, here is what I have learned. First of all, the 450F's are pretty good right out of the box. Fill them with gas and go ride. The only factors to consider are, they run cold and need a thermostat, they run rich and need an EFI tuner to lean them out, and when time to rebuild, they will cost you approx $2800.00 for a top quality race motor re-build. I got that quote from the FMF engine rebuild department. You do not "have to" have the tuner and thermostat. They work well and trouble free stock, but in order to run to their full potential I recommend those mods.
The 2-strokes run very well at those cooler temps. Do not need heated oil for the head and valve train, do not require a programmer to adjust fuel, and a rebuild can be done in your shop on a Saturday afternoon for about $180.00 and takes only about two hours. They do need jetted or a smart carb, and they do need a heater. The EFI throttle bodies are not prone to ice whereas the venturi in a carb will build ice in some conditions. Not every ride, but in certain conditions. Easy fix though for $69 bucks.
The KX500 in Napa would be a great platform to build a hot rod. They have a big motor and ton's of power but not as user friendly as the modern 4 stroke EFI's. The old WR500 I would probably pass on. The newer KTM 300 with e-start would be the best of both worlds. "summer and winter", "trail bike/snow bike". They come with a carb heater! electricity for extra's, very lite weight, and virtually zero maintenance. A rebuild is easy and inexpensive. That would be my first pick if I were to have one bike/12 months. They produce about 50hp, and work very well. They will keep up with the 450's, but not a "big hot rod", just a very fun and easy bike. Also, in the summer months, you would have one of the best woods bikes ever made. A 450 race bike does not make a fun single track bike at 8000' on a tight trail.
If I were to pick a "dedicated snow bike", and never take the track off. It would probably be a new KTM 450SXF. Very light weight, ton's of horsepower, more that the 500 XCW, close ratio transmission, and that little magic button, "E-start". That bike with a few "snow specific" mods makes a very nice snow bike. I have had the opportunity to ride one on demo's. It is super nice. Right there with it would be the Husqvarna 511. It is a cadallac with great performance and all the goodies. I tested one on a demo as well. It was super super nice. However, the kit for that bike is specific, and not universal.
For a big horsepower, aggressive hot rod, either the Service Powersports KX500AF or CR500AF. They are huge fun!!!
As for the APT smart carb on a 450F, I would love to try that myself. It is on the "to do" list. That would solve the over fueling conditions and piston wash for sure. It would also stay "spot on" every day regardless of where you ride. APT has racers world wide winning titles on 4-strokes with the "smart carb". It should work well on the snow, solving some EFI problems. They win the Pikes Peak race to 14000 feet with no tuning or adjusting! and out perform the EFI's! I would love to try one on a 4-stroke snow bike.
http://www.youtube.com/watch?v=BDWnuIoJpzY
Hope this helps, Randy
